Smoke Control BC Expert Evidence - Thursday 29th July 2021 (1/1)

29 July 2021 · Sara Menzies - Building Control Expert, Counsel to the Inquiry · 2:27:38
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Building control expert Sara Menzies gives evidence on smoke control system design, commissioning failures, and regulatory compliance

Key moments

Full transcript

00:00:26 good morning everyone welcome to today's hearing

00:00:29 hearing today we're going to continue hearing evidence from this barrel menses one of the experts instructed to help the inquiry would you ask ms menzies to come back in please thank you

00:00:50 good morning miss fences good morning all ready to carry on yes i am thank you thank you very much yes it's grogan thank you good morning ms menzies morning um we

00:00:59 we left off yesterday um where we'd started to look at the specifics of the design of the system and i'm just going to continue with that topic for a little longer

00:01:11 topic for a little longer in your supplementary report you explain your view that the psb technical submission for the smoke control system as conditionally accepted by building control in revision 3 was acceptable in

00:01:23 control in revision 3 was acceptable in principle yes and in paragraph 304 we don't have to go to it but the reference for the transcript is bmer

00:01:32 bmer 607 page 69 you say that by this you mean a performance-based strategy was acceptable in the circumstances of an existing building with retained smoke extract shafts

00:01:44 extract shafts can you just confirm what you mean when you say performance based um

00:01:49 um the system had to achieve a criteria of the air flow through the door and the

00:01:55 and the system would have to be designed to achieve that and to demonstrate that yesterday made reference to the air flow through the grills

00:02:08 through the grills that would have a bearing on achieving that performance standard but it would be variable and depend possibly depend from floor to floor to achieve it because that would have to be

00:02:20 achieve it because that would have to be as all part of the commission which i'm sure we'll touch on um demonstrated at each floor level and when you say a performance based strategy was acceptable are you saying

00:02:31 strategy was acceptable are you saying that this approach was acceptable or is it your view that the specific design as presented to the bcb was acceptable the approach was acceptable it's outlined in the guidance in various documents and

00:02:43 the guidance in various documents and the choice of the airflow through the door at two meters per second was in a recognized substantiated code and in my view that was an acceptable rate of flow for a

00:02:55 was an acceptable rate of flow for a performance and in terms of the proposed system is it right that whilst it may not have been intended as a full depressurization system that complied with bsen12101-6

00:03:09 system that complied with bsen12101-6 it was a system that created a pressure differential in the lobby yes it did it created a reduction of pressure in the lobby and at paragraph 120 of your report

00:03:20 and at paragraph 120 of your report which is page 19 for the transcript you say you do not believe that the intent of the design proposal was full compliance with bsen12101-6 correct

00:03:31 correct if we could look at paragraph 123 of your report which is on the same page that's page 19.

00:03:42 you say there no guidance existed to address the grenfell tower proposal a partially retained system that was to be modified the adoption of any particular guidance is not mandatory to achieve compliance with the building

00:03:53 achieve compliance with the building regulations and as outlined in my main report and you give some references there

00:03:58 there an applicant is at liberty to choose how to achieve compliance the building regulation requirements b1 through to b5 are substantive and not prescriptive the guidance must be appropriate for the

00:04:09 the guidance must be appropriate for the situation no one document is subjugated by another but one guidance document may be predominantly relevant and form the basis of a proposal with benefit from others

00:04:18 others however it should be remembered that guidance is based on the assumption that its interrelated measures are adopted and cherry picking from numerous documents is unacceptable without justification and can be inappropriate

00:04:31 justification and can be inappropriate it could be said that taking just one aspect of

00:04:35 aspect of bsen12101-6 was cherry-picking what's your view on that

00:04:41 in the context i view cherry picking it was not it was a performance that was

00:04:49 that was considered by the bsi as achieving an appropriate level for means of escape and for firefighting which was required in this instance

00:05:00 which was required in this instance the means of achieving that was

00:05:05 was via equipment and design that was

00:05:10 was achieving a depressurization but not in the context of the bsen12101-6

00:05:19 in as much as i had never seen a depressurization system in accordance with that guidance ever proposed in a residential situation it

00:05:31 proposed in a residential situation it would not have been appropriate to do so it would have taken substantial alterations similarly a pressurization system again a differential system would not be appropriate at

00:05:43 not be appropriate at greenville tower or in my opinion any other

00:05:46 other residential situation and why is that depressurization generally requires extract of the smoke from the fire cell the room of origin if

00:05:59 from the fire cell the room of origin if you like the fire which would not be inappropriate in a flat pressurization is an excellent form of smoke control but it requires a very

00:06:10 smoke control but it requires a very high standard of maintenance if the doors that are forming the barriers that maintain the pressurization and the differentials etc are under frequent use

00:06:22 differentials etc are under frequent use they become worn then requiring more maintenance the testing of it became become quite annoying to residents because of the fans starting up etcetera

00:06:36 fans starting up etcetera and it's

00:06:37 and it's a high level of capital outlay and a high level of ongoing maintenance

00:06:46 in terms of the actual design of the system dr lane has set out her view regarding the system in detail in her phase 2 report she concludes that the grenfell tower smoke control

00:06:58 that the grenfell tower smoke control system did not comply with the requirements of schedule 1 of the building regulations b1 b3 and b5 when handed over to the tmo and we'll go to the detail of her

00:07:09 and we'll go to the detail of her conclusions in a in a moment um have you had the opportunity to acquaint yourself with dr lane's conclusions i've looked at all 500 odd pages yes

00:07:20 i've looked at all 500 odd pages yes if we could go to a summary of her conclusions which are at blarp2

00:07:28 5036 page 25.

00:07:37 so this is in chapter 10 of her smoke control report she concludes there at 10.13.2 and that she's found no evidence that

00:07:48 and that she's found no evidence that either set of performance standards and she's referring there to both cp3 1971 and adb

00:07:56 and adb were considered as a means to derive design objectives nor were criteria set on that basis do you agree with our conclusion there i don't really understand the reference

00:08:07 i don't really understand the reference to cp3

00:08:10 to cp3 there were aspects of grenville town that complied with cp3 the smoke control in the lobby did not comply with cp3 but had been

00:08:21 did not comply with cp3 but had been accepted as a reasonable provision under the legislation at the time by the authorities having jurisdiction and what about her criticism that they

00:08:33 and what about her criticism that they didn't use adb to derive any type of design objective adb doesn't really did not really address mechanical systems

00:08:44 address mechanical systems it spoke about alternative to natural systems but didn't give it any technical data for the system other than by reference to other

00:08:56 other than by reference to other documents

00:08:58 documents she goes on to say at 10.13.4 that mechanical extract only systems are agreed to be inappropriate for the protective purpose of means of escape

00:09:09 protective purpose of means of escape and no consideration was given to this during the grenfell tower primary refurbishment do you agree with that i think

00:09:15 think dr lane's referring to depressurization this was not a full depressurization system it was a mechanical extract system that

00:09:26 system that afforded a level of depressurization in the lobby

00:09:31 the lobby at

00:09:32 at 10.13.5 she says that our bkc building control correctly requested a performance-based design as a route to compliance by means of the sca guide however she's not found any evidence

00:09:43 however she's not found any evidence that psb's lobby smoke control system was designed on that basis i do not recollect any disclosure that building control requested a

00:09:54 building control requested a performance-based design it requested details of the existing system to show it was a no worsening situation

00:10:06 it was a no worsening situation or as an alternative it requested details of a new system the

00:10:13 the observations provided by mr hansen the rbkc experts in the field of the smoke control stated that he based his actual

00:10:24 stated that he based his actual observations b1 being a wider than the smoke control alone

00:10:30 alone on adb

00:10:33 on adb and

00:10:34 and bs9991

00:10:35 bs9991 as appropriate he did recommend that the components of the system accorded with the sca guide and the sca guide in turn refer to other

00:10:47 the sca guide in turn refer to other documents

00:10:48 documents for standards to be attained etc she also concludes at 10.13.6 that the commissioning process fell below the standard to be

00:11:01 process fell below the standard to be expected she says there that it did not demonstrate compliance with regulation seven of the building regulations do you agree with that the commissioning process as i understand the commissioning

00:11:13 as i understand the commissioning process

00:11:14 process is merely

00:11:15 is merely to demonstrate that the system works as intended

00:11:20 intended the reason building control bodies generally do not attend commissioning processes

00:11:25 processes is that they take so long they can be very time consuming very intense lots of people involved particularly when there are a number of flaws that need to be addressed at the same time

00:11:37 addressed at the same time and

00:11:38 and the

00:11:39 the actual standards of the equipment etcetera should have been dealt with as they were installed and checked by the installation engineers as being adequate the compliance with regulation seven is

00:11:51 the compliance with regulation seven is basically they are they are being fit for purpose and are installed in a workman-like manner and that should have been addressed all the way through the construction at the commissioning is too late

00:12:03 at the commissioning is too late and as i understand it commissioning engineers who may have never seen these the site before

00:12:12 are not looking at the standards of the equipment but making sure that they are literally wired up correctly and running in the correct order etc she also concludes at 10.13.7

00:12:25 she also concludes at 10.13.7 that the fire performance standard for the dampers most importantly as well as the newly installed portions of the ductwork did not comply with either the performance standards for a smoke control system nor the requirements for a protected shaft i would agree with

00:12:38 a protected shaft i would agree with that and

00:12:39 that and from all the disclosures i have seen there is no evidence that building control sought clarification and sort test certificates or anything associated with establishing the

00:12:50 associated with establishing the performance of those dampers so does that

00:12:53 that lead you then to also conclude that there were non-compliances with b1 and b5

00:13:00 b5 yes because there was no conclusion that indicated that there was full compliance and in those circumstances um should building control have

00:13:12 should building control have rejected the proposal or at least not issued a final certificate not issued a final certificate which i have

00:13:20 have stated in my supplementary report in the event that the panel accepts dr lane's conclusions there that the system did not comply in other ways with b1 and b5 is that something that you think

00:13:32 b5 is that something that you think building control ought to have picked up

00:13:38 i would have to know what those particular aspects were [Music]

00:13:45 [Music] from the regulatory side the system as installed was not shown to be compliant

00:13:55 compliant because it was altered after building control

00:13:58 control last

00:13:59 last saw it demonstrated

00:14:03 and i'm still confused as to what these additional events that were requested by building control were and at what stage they were requested and whether they had ever been mentioned

00:14:15 and whether they had ever been mentioned before because there is a disclosure that says building control agreed that we didn't need a vent then we get the request after the demonstration for the additional

00:14:28 demonstration for the additional event and the s2 i believe from memory annotation by building control on the drawings

00:14:36 drawings includes

00:14:37 includes inlet vents to lobby at the lower level so i'm very confused as to what was actually thought to be required and what was actually

00:14:48 and what was actually installed at the final uh completion and we'll come on to that topic and look at mr hansen's evidence on that slightly later this morning

00:14:59 moving on to a new topic now which is the smoke control association guidance at paragraphs 121 and 122 of your report which is on page 19.

00:15:12 you explain that the various the recommendations of the various bsen1201 specifications relating to the installation components testing and maintenance were relevant and were

00:15:23 maintenance were relevant and were similarly referenced in the smoke control association guidance and you say in my experience the sca guidance was generally recognized as authoritative and relevant and was applied to smoke control schemes at the

00:15:34 applied to smoke control schemes at the time of the full plan submissions there was no other performance based guidance available and bs12101-6 provides a performance criteria

00:15:44 criteria moving on in your report to page 55 paragraph 219.

00:15:52 you also say there that you consider the sca guidance was an appropriate reference in the circumstances there was no other performance related guidance and no guidance that's specifically related to existing

00:16:03 specifically related to existing buildings

00:16:05 buildings can you explain what to what extent you would have expected building control to consider the proposal against the sca guidance

00:16:14 so it's acceptable in principle as a starting off point but how would you expect them to follow it through well the sca guidance addressed mechanical extract natural inlet as a

00:16:25 mechanical extract natural inlet as a system of smoke control it was also guidance that was more recent in its version

00:16:37 12101-6 is getting quite old now and

00:16:42 and it was

00:16:44 it was guidance that was compiled

00:16:48 compiled by persons and organizations who were literally at the coal face dealing with these installations on a day-to-day basis

00:16:57 basis and was

00:16:59 and was contributed to by building control bodies and the fire service who would be one of the end users it's right there that the sca guidance

00:17:10 it's right there that the sca guidance also sets out a process for arriving at your final design it does

00:17:16 it does would you expect the bcb to insist upon that process being followed so selecting your performance criteria and justifying them not insisting because they can't insist

00:17:28 not insisting because they can't insist it would be a case of if you followed this guidance that would be something we would be supportive of in our overview and it would make sense for you to do it

00:17:41 would make sense for you to do it particularly in this case when mr hansen was actually sitting on the committee but irrespective of that it was something that gave a constructive process

00:17:50 process by which people could relate to a process as submitted to building control and mr hanson's confirmed his view in his witness statement um for the ref for

00:18:01 his witness statement um for the ref for the transcript the references rbk3033894

00:18:07 page 9 paragraph 52 that the new smoke control system was designed in accordance with the principles of the 2012 revision of the sca guide

00:18:16 sca guide mr mani however said that the system was not designed in accordance with the saa guy process and the reference for that is day 155 page 135 line 20

00:18:29 page 135 line 20 when he was asked whether the system was meant to be designed in accordance with the process set out in the sa guide he said no because we couldn't follow it

00:18:40 given the conflict of evidence there how do you reconcile the fact that mr hansen on the one hand thought that that's what was being followed that mr money says it wasn't the sca guide puts great emphasis

00:18:54 wasn't the sca guide puts great emphasis on cfd

00:18:55 on cfd which was decided not to be done at temple tower the

00:19:02 mr mani's statement i believe related to the fact that he designed it from the basic principle of achieving a flow rate

00:19:15 principle of achieving a flow rate which

00:19:16 which the sca guide then directs you back to 12101-6

00:19:23 for pre for pressure differential systems

00:19:27 systems but the sca guidance was more akin to what was being proposed

00:19:34 mr manis proposal didn't set out on what it was based

00:19:41 based but then neither did the building control

00:19:44 control documents that have been made available and the records cannot be found there's no record of what the discussions were held what was said between the parties

00:19:56 held what was said between the parties and why the conclusion was drawn but looking at it if you like as a separate review

00:20:03 review it seemed appropriate to me for the purposes of the building regulations

00:20:09 if we could just look at the sca guide 2012 and one particular aspect of it it's clause 5.3.1 which is a lfb nine two 305924 one page ten

00:20:30 and it says there design conditions right at the bottom design conditions and performance criteria should be agreed with the approving authority as part of the approval process

00:20:41 part of the approval process preferably in advance of any of detailed calculation or modelling is it clear to you having looked at the documentation what design conditions and performance criteria were agreed in advance for

00:20:53 criteria were agreed in advance for grenfell tower not what was agreed in advance of the submission of revision03 i do know that a

00:21:04 i do know that a clause was removed from revision02 where it's i think there was a typing error anyway because it said it extracted into the staircase which was obviously totally

00:21:15 staircase which was obviously totally unacceptable but the reference saying it wasn't designed to 12101 etc was removed as well

00:21:23 well so

00:21:24 so a correction would have been better but the whole sentence well the paragraph was removed but

00:21:34 but the

00:21:35 the justification for the removal was only a comment by

00:21:42 by rights

00:21:43 rights saying that they had spoken to building control

00:21:46 control and mr hansen said this is not what we agreed but i can't make out from the disclosures whether the extraction into the staircase was what not which was the

00:21:57 the staircase was what not which was the question that mr hansen was raising or the whole paragraph in its entirety because there's no explanation from either as to why just focusing on the

00:22:08 just focusing on the idea that design conditions and performance like criteria should be agreed with the approving authority do you see any evidence that that was positively done

00:22:18 done not recorded as such no whether it was discussed and not recorded i don't know are you critical of that failure to record

00:22:28 record that that process had been carried out yes yes because it's a record leading up to the decision but then as we never had a decision on the overall project um this standalone aspect is the

00:22:42 um this standalone aspect is the probably the most detailed recording but it is has gaps in leading up to why that particular process was adopted and why would it be important to

00:22:54 and why would it be important to to record what had been agreed because in it's a record that shows what

00:23:02 what why it was installed it's a record that shows that building control had done its due diligence in its job if you like and it's also a record for those that come

00:23:13 come after the installation has been installed and been running for some time if for instance a component is no longer available you can look at what's gone before what was discussed why it was achieved and if the

00:23:26 discussed why it was achieved and if the variation that you're now compelled to infor

00:23:31 to incorporate in the system will have a detrimental effect on it

00:23:38 if we could look now at clause 5. i'm sorry can i just interrupt you for a second to ask this i can understand that the questions about the design of the system

00:23:49 questions about the design of the system may be interesting maybe important as maybe questions of record keeping but from the point of view of compliance with the building regulations um

00:24:01 um does it matter so long as the airflow was achieved in practice now right

00:24:10 right but

00:24:13 it's a good it is always good practice whether you're on the building control side or on the design side to record

00:24:20 to record the route that you have went to achieve what you did yeah i don't dispute that for a moment i just want to be clear though because sometimes one gets confusion between it's not recorded and

00:24:32 confusion between it's not recorded and whether it happened yes and of course we do have the data from the commissioning exercise

00:24:40 exercise which presumably would be available subsequently if anyone wanted to know how it would have performed yes yes so there to something there's a record of actual performance

00:24:52 record of actual performance um even if not a record of how you got to the uh

00:24:58 uh to that point the

00:25:01 the the record of the actual performance demon is indication the system achieved the design which is what you want to know

00:25:09 know well it's a record is it not of the fact that the system achieved uh a performance level which satisfied the building regulations

00:25:21 which satisfied the building regulations yes

00:25:21 yes correct and they may also have achieved the design if you know what the design was but that doesn't detract from the fact that it achieved what was required to satisfy the building regulations

00:25:32 to satisfy the building regulations exactly that because it was accepted that design criteria was accepted as satisfying the building regulations yes yeah all right thank you thank you very

00:25:44 yeah all right thank you thank you very much yes i'm sorry ms grogan too thank you

00:25:49 so we were just about to look at clause 5.4 of the sca guy which is on page 14 of this same document

00:26:00 and it's the bottom half of the page there

00:26:03 there and

00:26:05 and we can see that the documentation required by the sca guide to allow relevant parties to assess the analysis undertaken in relation to checking and meeting the required performance criteria should include at least and

00:26:17 criteria should include at least and then there's a list a description of the residential area and the proposed ventilation system the design criteria and performance objectives of the analysis the scenarios investigated

00:26:28 investigated details of the techniques used and related information and over the page the results of the analysis and a statement as to whether the design criteria and objectives have been met um mr hansen in his evidence suggested

00:26:41 um mr hansen in his evidence suggested that this list was in relation to modeling a scenario rather than considering a performance based criteria and the reference for the transcript is day 154

00:26:51 day 154 page 190 lines two to eight um can you help us if one was following the sca guide um in establishing performance criteria as we've just discussed and as you've

00:27:02 as we've just discussed and as you've just had an exchange with the chairman about

00:27:05 about would you expect that information to have been provided for grenfell i think

00:27:11 i think to

00:27:13 to a level it was provided if we can go back a page

00:27:22 a description of the residential area and the proposed ventilation system there was

00:27:28 there was a description of that a high level and i think you it would be acceptable to assume

00:27:36 assume that this coming after the main submission of the full plans and plans of the proposal of works having been submitted

00:27:45 submitted the people involved including building control had an awareness of the residential area and the proposed ventilation system the design criteria was the performance

00:27:56 the design criteria was the performance criteria

00:27:57 criteria as was the objective the analysis leading up to that may be a little vague in the paperwork the scenarios investigated there was only one scenario

00:28:11 investigated there was only one scenario and that was a fight in a flat and persons leaving and the whole concept to stay in place had been described previously details of the techniques used and

00:28:22 details of the techniques used and related information i'm not quite sure what that would be that's probably where the

00:28:29 the reference to modeling etc by mr hanson is and if you can go down the page

00:28:42 the results of the analysis was the calculation that was done by mr mani

00:28:49 mani and the

00:28:51 and the aspirational flow that was achieved by the commissioning certificate at the time

00:28:59 time although it must be noted that that was not the final system that was installed

00:29:08 when this list of matters that should be addressed was put to mr hansen he acknowledged that it should have been documented better how the considerations were arrived at and the reference for

00:29:21 were arrived at and the reference for that is day 154 page 191 lines three to six

00:29:26 six in light of his acceptance that things could have been done better was it right for building control to proceed to approve the system in the absence of proper recording [Music]

00:29:38 so the purpose of the building regulations i think yes

00:29:43 think yes in as much as the building regulations were looking for a result to be achieved and that result was achieved

00:29:55 achieved at the time but not the final system because that was never recorded

00:30:01 so as you've said in your evidence before the focus is on what happened at commissioning and was it demonstrated that this flow rate was achieved rather than

00:30:11 than when looking at it on paper in advance whether all of the information was there to permit building control to carry out an assessment yeah the looking at it in advance gives an

00:30:23 the looking at it in advance gives an indication that it's viable and will fulfill the function of the building regulations if it shows a total non-compliance

00:30:36 a total non-compliance or something that didn't fulfill or aim to fulfill the function of the building regulations it could have been rejected at that point although this proposal wouldn't would have been rejected on the basis

00:30:48 would have been rejected on the basis that it's unacceptable not this your fall plans application is rejected

00:30:55 rejected in this particular case the full plans application was never passed or approved it went outside the time limit no overall um

00:31:06 no overall um view of building control on the the proposed project was ever given

00:31:12 so it would have been this is unacceptable and if they said we're going to proceed with it anyway then it would be a case of what we'll see on site what is actually

00:31:23 what is actually produced and whether that is adequate it's in circumstances where a design criteria or performance criteria is put forward but as we've discussed not

00:31:34 discussed not explained or justified and building control looks at it and then you get to cite and something goes wrong is it not too late by the time you've got to cite

00:31:46 late by the time you've got to cite and the commissioning process it is too late in the in the case of grenfell i would have said

00:31:53 have said although there was not the detailed analysis and the whole matrix if you like of how i arrived at this

00:32:02 this decision

00:32:04 decision there was nothing to say this will not perform on site there was nothing to say this is totally wrong

00:32:13 wrong i think as mr marnie said a lot of it was based on his experience and he didn't put it down on paper and perhaps mr hansen

00:32:24 and perhaps mr hansen in his experience knew that the intent would work although he suddenly decided towards the end although the commissioning demonstrated the flow was achieved

00:32:36 the flow was achieved that he thought there should be and recommended additional ventilation at ground level

00:32:51 at paragraph 183 of your report which is on page 52 of the mer at

00:32:59 at 607

00:33:00 607 [Music]

00:33:01 [Music] you say that the psb technical submission rev 3 does not state that it's based on reliant on or has adopted the sea guidance and the guidance is not quoted anywhere

00:33:11 anywhere in the document should it have done so

00:33:18 mr marnie said it wasn't based on the sca guidance on that basis no it wouldn't have been the the conditional approval if you like of revision03

00:33:30 of revision03 stated that it should comply with the components aspect as recommended in sca guidance

00:33:38 guidance so then if you like that almost became conditional of it but if it was proven that it hadn't followed it but was adequate in any event

00:33:50 but was adequate in any event then

00:33:51 then the system finally would have been accepted

00:33:57 and moving on in your report to page 54 paragraphs two one one and two one two thinking about the proposal as it came across mr hansen's desk you said there are several aspects that you would have

00:34:08 are several aspects that you would have expected to be queried by an experienced bcb surveyor and they are did the proposals follow any aspect of the sca guidance mr hansen having stated that the

00:34:19 mr hansen having stated that the proposed system was designed in accordance with that guidance and if so why was it not referenced in the technical submission what was the temperature rating of the smoke extract fans what was the fire resistance of the proposed dampers to

00:34:30 resistance of the proposed dampers to the smoke extract shafts and were the dampers to the smoke extract shafts the fire and smoke damper is required to maintain compartmentation and deter smoke spread and then you go on to say you've seen no disclosure that indicates

00:34:42 you've seen no disclosure that indicates that these issues were queried at the time

00:34:44 time of the bcb review in light of your view that those matches were not queried should building control have accepted the proposal in principle

00:34:56 accepted in principle but i should have queried those aspects and that could been part of the conditional approval the

00:35:08 the aspect i've i highlighted in my main report where the division of mr hansen and mr hoban mr hansen being a consultant to mr hogan

00:35:21 mr hansen being a consultant to mr hogan the smoke extract shaft dampers etc were relevant under requirement b3 as well

00:35:31 well so one of the two should have been looking at them mr hansen said he never carried out any site inspections so

00:35:40 so implying in my view that mr hoban should have been looking at the fire rating of the dampers so this is where this confusion arises on several aspects

00:35:51 arises on several aspects of the building regulations review of the whole project but those are matters which were should in my view have been queried would have been a bit beneficial to both

00:36:03 would have been a bit beneficial to both parties to have known at the time prior to installation but all the building control body can do is ask for that information if the scheme proceeds and that

00:36:15 if the scheme proceeds and that information is not forthcoming they can't stop it all they can say at the end is well basically we warned you now

00:36:23 now because we don't know if these dampers are adequate we need you to prove it or you replace them with something that we both agree is acceptable and

00:36:34 and i think it's right that there's no evidence that that happened so there was no querying later on not that i've seen of the dampers and no request to install something different

00:36:45 different in those circumstances should building control at the end of the process have issued

00:36:50 issued its certificate so in the absence of information that you've listed there no they should not um i think i said in my main report that the

00:37:00 that the completion certificate should not have been issued the

00:37:04 the aspect of the smoke control was only one part of that recommendation that they should not have issued it

00:37:12 issued it or conclusion rather

00:37:15 moving on to a new topic which is extended travel distances can we go first to adb which is clg 50224

00:37:28 50224 and this is the 2006 edition incorporating the 20 2007 2010 and 2013 amendments go to page 31

00:37:42 and we zoom in on 2.25 which is at the top of the page

00:37:50 and it says there should therefore be some means of ventilating the common corridors lobbies to control smoke and so protect the common stairs this offers additional protection to that provided by the fire doors to the

00:38:01 that provided by the fire doors to the stair brackets the ventilation also affords some protection to the corridors lobbies and then it says this can be achieved by one of two ways natural or mechanical

00:38:15 is it correct that this is drawing attention to the need to ventilate both um to ventilate the common lobbies first of all so to protect the stairs but second of all also to provide some

00:38:26 but second of all also to provide some protection to the lobbies themselves

00:38:30 yes and is it right that what the guidance is saying there is that you need to think about the escape route in its entirety so a single-minded focus on the stairs would not be

00:38:41 focus on the stairs would not be appropriate you would consider the escape from the room within the flat through the flat hall through the common horizontal areas down

00:38:52 through the common horizontal areas down the stair

00:38:53 the stair right out to somebody standing outside in the fresh air and that would apply whether or not travel distances are extended correct

00:39:04 if we go now to the 2015 version of the sca guide

00:39:08 sca guide which is rbk402932

00:39:12 page six

00:39:18 now we've heard the evidence and you've said in your report that it's the 2012 guide

00:39:22 guide that would have applied to the assessment of the remote control system but the 2015 guide expresses the principle as well which is why i've taken you to it

00:39:33 which is why i've taken you to it it says at the beginning of the section titled primary objectives um where the travel distances are no more than 7.5 meters in distance from the door to the staircase brackets or

00:39:44 the door to the staircase brackets or sterile lobby the most remote apartment to the most remote apartment entrance door the primary objective of smoke control in residential buildings is to protect the staircase enclosure by

00:39:56 protect the staircase enclosure by ensuring that the stairways remain relatively free from smoke and heat in the event of a fire within a dwelling and it goes on to say however where corridors are extended the primary objective of the smoke

00:40:07 the primary objective of the smoke control system is to protect both the common corridor and the staircase enclosure

00:40:12 enclosure there are considered to be two forms of extended corridors and then it goes on to define extended travel distances of typically no more than 50 meters and then significantly extended travel

00:40:23 then significantly extended travel distances

00:40:24 distances which have more than 15 meters travel distance

00:40:28 distance and so if you keep that in mind we'll now look at one farther standard which is clause 0.2.3 of bs 9991 2011 and that is bsi

00:40:39 and that is bsi 50621 page 11.

00:40:47 and at 0.23 it says in the second paragraph smoke can be controlled in the common areas through fitted ventilation systems which are either natural or mechanical

00:40:58 either natural or mechanical these ventilation systems have two main purposes the first of which is to provide some protection to the stair core and the second of which is to aid firefighters when tackling a fire ventilation systems can also be used to compensate for extended travel distances

00:41:11 compensate for extended travel distances within the common corridor leading to the stairs and thereby help occupants to escape safely where smoke control is used to provide compensation for extended travel distances it is the responsibility of

00:41:22 distances it is the responsibility of the designers to demonstrate that the ventilation system can provide tenable conditions bracket c annex e close brackets for the occupants using the route with extended travel distances

00:41:35 travel distances do you agree that therefore adb the sca guide 2015 and bs triple nine one

00:41:41 nine one all anticipate the use of a smoke control system to protect not just the stair but also the common corridor in the in the context of an extended

00:41:53 in the in the context of an extended travel distance yes the smoke ventilation system will also afford some protection to the common lobby

00:42:05 lobby and i'll say lobby in the context of grenfell because it was not a corridor as such and there's a big debate as to what's a lobby and what's a corridor

00:42:16 corridor in my view a corridor is longer

00:42:20 longer and bigger than a lobby

00:42:25 you will by virtue of the smoke control system running

00:42:30 running have some degree of protection in that protected lobby whether the travel distance is 7.5 or longer

00:42:42 longer the whole

00:42:43 the whole aspect has to be considered in the concept

00:42:46 concept with

00:42:48 with recognizing the concept of how these

00:42:52 these recommendations are compiled on the basis of the stay in place protocol and the compartmentation the fact that the flat on fire will be the initial flat and perhaps hopefully

00:43:05 the initial flat and perhaps hopefully the only flat necessary to evacuate therefore when they evacuate they open the door to the flat which should be a fire resistant self-closing

00:43:17 should be a fire resistant self-closing smoke sealed door they will come into the common area they have left their flat because they have either seen the fire

00:43:27 the fire noticed smoke or have been warned of fire by virtue of the smoke detection in their flat activating and that should activate in the early stages of the fire so that they should be

00:43:39 of the fire so that they should be leaving the flat in the early stages of fire

00:43:43 fire that flat entrance door closes behind them

00:43:47 them should close behind them if sufficient smoke has escaped from the flat to activate the smoke detector in the common area that ventilation system that smoke

00:43:58 that ventilation system that smoke control system will activate

00:44:02 they then move into the stair and go down and evacuate the building should anybody else on the floor become aware of a fire and feel the need

00:44:13 become aware of a fire and feel the need to evacuate when they come out into that lobby that smoke control system may or may not be running if it's running it will be pulling air from the stair

00:44:26 pulling air from the stair from gaps under the door etcetera when the door is opened into the stair it will boost up and further dilute the smoke in the lobby but it would be a limited amount of lob of smoke in the

00:44:38 limited amount of lob of smoke in the common lobby provided the front door to the fire flat had closed so there is a level of protection but it is recognized in

00:44:48 in guidance and commentary and i think generally known throughout the industry that during fire fighting the only

00:44:57 the only practical way of holding the smoke back from entering the stair to a degree is if the stair

00:45:06 stair is part of a pressurization system that will hold the smoke back otherwise it is inevitable that smoke will pass into the common stair

00:45:18 will pass into the common stair now should the fire brigade determine that further persons need to evacuate

00:45:26 evacuate their decision as to whether to close the door to the stair close the door to the flat stop firefighting at that particular time where persons

00:45:37 that particular time where persons evacuate is entirely up to them and it's a dynamic decision only they can decide but in circumstances where there are extended travel distances it is right

00:45:49 extended travel distances it is right that the guidance points to the fact that the lobby the smoke control system should protect the lobby as well as the stair yes and it should

00:46:00 as well as the stair yes and it should achieve certain levels of tenability temperature visibility which is not specified for a code compliant distance so

00:46:12 so not all new projects adhere strictly to the 7.5 meters travel distance

00:46:19 distance because 7.5 meters as probably has been said

00:46:23 said will be adequate for joe public perhaps not somebody who has breathing difficulties has just come back from skiing has broken their leg etc or is of a certain age

00:46:35 etc or is of a certain age or has some form of impairment so

00:46:39 so it's

00:46:40 it's you know a meter half a meter each way

00:46:44 each way is probably not going to make much difference i'm sure the [Music]

00:46:48 [Music] panel has been informed the inquiry has been informed at one point we had mandatory rules for means of escape way back from the 1985 regulations that was done away with

00:47:00 was done away with one reason i believe was because it was very rigid and did not allow circumstances where a slight extension would be adequate

00:47:11 would be adequate but definitely if it goes up towards 15 meters

00:47:15 meters or

00:47:16 or perhaps even sort of 10 or so meters you would be then start looking in an extended travel distance situation

00:47:25 situation for those tenability criteria to be demonstrated and that is usually done by cfd

00:47:31 cfd in the case of grenfell in my view the travel distances were not extended because they complied with the criteria when it was built

00:47:44 criteria when it was built so whilst in the context of modern standards it was extended and it approached the magic 15 meter distance

00:47:55 distance depending on how you or you were permitted under cb3 to go up to 15.

00:48:02 i know that the bre measured that travel distance i know dr lane measured it i have measured it on the plans from scale and we've come up with three different versions

00:48:13 versions of how far that distance is um it's not unusual in scaling to get a an incorrect distance but it gives you an indication and that's what you do when you do the

00:48:24 and that's what you do when you do the plans under building rigs you're doing the review you're scaling it or you're taking dimensions that are put on the plan by the architect so in the com in particular in grenfell

00:48:35 so in the com in particular in grenfell tower

00:48:36 tower the

00:48:37 the distance which was not 15 meters it was less would have been permitted under cp3 at the time

00:48:48 so just going back to bs triple nine one where it says it's the responsibility of designers to demonstrate that the ventilation system can provide tenable conditions for the occupants

00:48:59 conditions for the occupants um using the route with extended travel distances is it your view that for grenfell tower that

00:49:06 that piece of guidance didn't apply so there was no

00:49:09 was no requirement for the designer to demonstrate that tenable conditions in the common lobbies could be achieved had i been looking at it i wouldn't have raised the matter of extended travel distance as being a

00:49:21 extended travel distance as being a criteria which they would now have to address under the new proposals the refurbishment proposals i readily acknowledge some others

00:49:32 acknowledge some others another building control officer may have in fact raised it as an issue if they were looking at distances of 15 meters

00:49:41 meters if a building control office had raised it they would if following the guidance at that time would have been looking putting sprinklers in all the flats which would not been viable

00:49:53 which would not been viable from the proposals

00:49:57 the building owner's point of view perhaps

00:50:00 perhaps but i personally would not have considered it being

00:50:05 being an extended travel distance in the context of grenfell tower and you

00:50:10 and you you refer to what you personally would have done is that a matter that there's a range of reasonable views so bearing in mind the standard of a reasonably competent bcb um

00:50:21 um would it be within the range of reasonable responses for a bcb to query the travel distances and ask for a demonstration uh that at grenfell tower those extended travel distances

00:50:33 travel distances could still provide tenable conditions with the smoke control system

00:50:38 in all honesty i can't give you a view on that in as much as these systems

00:50:45 systems as exactly as per grenfell tower i've never seen another one in existence so i couldn't say in all honesty it's down to personal judgment and interpretation by the

00:50:57 judgment and interpretation by the building control body and mr hansen's evidence was that um in the context of protecting the common corridor where

00:51:08 protecting the common corridor where there were these extended travel distances but less than 15 meters he described that as a qualitative decision not based on any kind of modelling or anything of that nature and that's it paid day 154 page 168

00:51:21 and that's it paid day 154 page 168 lines 2 to 25 does that reflect what you've just said that

00:51:26 that it's a matter of professional judgment as to how you approach it as a bcb yes

00:51:33 i'm going to ask you now about the shape of the lobby so the eye shape of the lobby we've heard evidence in relation to that and in his evidence mr mani on day 155

00:51:45 and in his evidence mr mani on day 155 page 88 lines four to seven uh which we don't need to go to said the system i'm putting forward isn't designed to deal with the eye shaped lobby

00:51:53 lobby and no system will remove those dead spots whether it be natural or mechanical because it's a dead spot is that an issue you would have expected to see

00:52:01 to see considered in the design documentation

00:52:08 again ideally it would have been a part of a discussion recorded or set out in the document however in the case of the layout of grenfell tower

00:52:20 grenfell tower unlike most modern layouts that comply with the travel distance or not you are actually extracting in two points so you were drawing away from two

00:52:31 points so you were drawing away from two points some of which were quite near these dead ends i'm not convinced that the dead-end situation would have been significant

00:52:44 significant it would add to my view that as was usual in these circumstances you would have requested demonstration that of a cold smoke

00:52:55 of a cold smoke test to show what the situation was with the flow of smoke away from the stair etc

00:53:06 the layout of

00:53:08 of the opposing extract and the proximity to the dead ends would

00:53:16 would in my view have likely resulted in some movement

00:53:20 movement but as to whether it would have been an earthquake level that would been demonstrated as being given the visibility that one would expect or the guidance gives you

00:53:31 the guidance gives you i don't know mr manny's experience as an engineer a mechanical engineer dealing with air movement smoke control systems far exceeds mine

00:53:44 exceeds mine so

00:53:46 so i can't say whether or not it would have if that was his stance then i would have expected that to have been recorded in the discussions

00:53:58 been recorded in the discussions and addressed but i don't think it played a significant role in the system that he designed there's nothing to direct me towards saying this was a system that would deal with

00:54:11 system that would deal with well as he said it wouldn't deal with the aspects of the dead-end situations and in those circumstances should the bcb have

00:54:23 thought about whether or not that affected compliance with b1 and b5 you would always consider dead-end situations in the context of smoke movement

00:54:35 smoke movement but as

00:54:36 but as the prime concern was to protect the stair and

00:54:45 and in my view there were not extensive dead ends

00:54:48 ends i can understand why it was not apparently considered under the proposed as a grantful to any higher degree

00:54:58 degree but it would have been a general re aspect that you would consider as a building control officer in any project with uh smoke control the same would arise for a natural

00:55:10 the same would arise for a natural system as well as a mechanical system i'm going to ask you about that because the dead ends if we're going to call them that were built into the structure weren't they yes and therefore and because the

00:55:22 because the new system was drawing or designed to draw smoke from two locations in the lobby rather than just one presumably there was no it was no

00:55:33 presumably there was no it was no more unsatisfactory than the original arrangement in my view it would have been better well yes yeah

00:55:42 yes yeah in which case there wasn't much that building control could say about it was that not really no um thank you

00:55:51 thank you is that right even in circumstances where they were applying modern standards so they were seeking achievement of b1 and b5 i think the applying modern standards was aspirational

00:56:02 aspirational but in an existing building it would be rare that you could apply all modern standards in this particular case the size of the vent

00:56:14 vent vent shafts didn't comply with any guidance at all and although i hesitate to raise the colt system which has been discussed at length in dr

00:56:26 which has been discussed at length in dr lane's night length that has been addressed in dr lane's report the reason people often go for the colt system is that the vent duct is smaller than the

00:56:38 vent duct is smaller than the recommendation but it's been shown to work

00:56:43 work on a certain layout it's all been all the cfd analysis has been done which is expensive and can run for weeks to get an answer has been done um so people sometimes opt for that for

00:56:55 um so people sometimes opt for that for the smaller size vent shaft in this case i don't think they even added up to the cult size shaft

00:57:07 and in circumstances where you have the dead end and there's a potential for smoke not to be cleared from that dead end how can the bcb satisfy itself that there would

00:57:18 the bcb satisfy itself that there would be an adequate means of escape through the lobby and out to the stair if the bcb was concerned that there was a dead dead-end situation where there would be

00:57:29 dead-end situation where there would be a lack of

00:57:31 a lack of dilution

00:57:33 dilution in that area in order to request substantiation that it was not a problem they'd have to establish that there was a problem in the first case

00:57:47 these

00:57:49 in the situation of a layout with dead ends you would consider the escape from the individual flats on the basis of a stay in place

00:58:00 stay in place and then you would say the these you would i think you would surmise that had the dead end situation been an issue it would have

00:58:11 situation been an issue it would have been because it wasn't the fire flat that was escaping the fire and the smoke should be behind you and you're running ahead of it it would have been a situation if the fire flat

00:58:24 if the fire flat fire had caused an issue within the common lobby and the residents on the same floor were trying to escape through that

00:58:35 that lobby but

00:58:36 lobby but in the case of an existing situation it would be an issue

00:58:44 an issue as originally approved as opposed at the same time as being the proposed

00:58:50 proposed scheme

00:58:51 scheme there was no worsening if you like of the situation and because you were now going from natural to mechanical you were probably improving

00:59:01 improving the situation in the lobby for that other flat occupants to escape

00:59:10 moving on to foreseeable scenarios and door opening conditions now at paragraph 116 of your report which is on page 18.

00:59:25 you say there that sca guidance makes no specific recommendations relating to firefighting operations and you've said this in oral evidence today these will be dynamic at each incident but an experienced competent

00:59:37 incident but an experienced competent bcb should be aware that it is likely firefighters will approach a fire from a floor or floors below where they have connected hoses to the rising water main and the hoses will retain open doors between the lobbies and the stair

00:59:52 and then going forwards in your report to page 65

00:59:59 at paragraph 271 it says whilst neither version of the sca guidance specifically stated the stair doors on the lower floors should be considered as being open in

01:00:10 should be considered as being open in addition to those at the level of the fire

01:00:13 fire a competent building control surveyor familiar with smoke control systems supporting firefighting operations and the particular scenarios associated with a class b installation would have been aware of the need to consider additional

01:00:24 aware of the need to consider additional doors being open uh and then at paragraph 275 on which is on the same page at the bottom it's you say you've seen nose disclosure that suggests the bcb required open doors

01:00:37 suggests the bcb required open doors other than on the fire floor as part of the commissioning of the system or the witnessing of the system and there's no indication that the bcb took these additional doors into consideration when reviewing the smoke control proposal

01:00:50 control proposal is it right then that you would have expected a reasonably competent bcb to have required the commissioning or testing process to address different door opening scenarios

01:01:02 door opening scenarios yes and in witnessing uh the demonstration i would have expected them to have asked for certain doors to be held open on the lower floors to demonstrate the effect

01:01:17 lower floors to demonstrate the effect it was not a commissioning matter in as much as it was not part of the design as i understand it can you help me with this because i'm

01:01:28 can you help me with this because i'm sure the

01:01:29 sure the lack of understanding on my part but i as i understand it the system is designed to draw air

01:01:37 air from the stairway into the lobby and there

01:01:40 there thereafter up the shaft why does it matter where the air has come from

01:01:45 come from when it emerges from the stair shaft into the lobby i'm not an uh mechanical engineer but my understanding is that this whole system works on balancing

01:01:57 works on balancing and therefore it would be just to demonstrate that there was not an imbalance of

01:02:05 of the air flows through from the stair through the doors but also

01:02:11 but also it would be an indication of where the likely direction of flow would be

01:02:19 would be if it would would this influx of air cause any additional drawing from the fire flat

01:02:29 but at the moment i can't see how it could because um effectively you're just drawing air from the whole of the stairwell

01:02:39 and the stairwell is open to the atmosphere at the top so

01:02:44 so in one sense you're drawing air on the faceship from practically everywhere and i can't see why having a door open on the floor above or the floor below should should affect the rate of flow

01:02:56 should should affect the rate of flow through the door you're concerned about uh i have mr marley said it wouldn't but i may have misunderstood this is why i was

01:03:04 was asking the question from my understanding of the way these systems work i doubt whether it would have affected it but it would be a demonstration of what

01:03:16 but it would be a demonstration of what would be happening on the night of the fire

01:03:19 fire with the fire brigade holding doors open it's a bit different in grenfell in as much as in the under current guidance the brigade are asked sorry the brigade prefer and the

01:03:32 asked sorry the brigade prefer and the guidance is that the dry riser or the wet riser is in the stair under previous guidance it asked for it to be in a ventilated protected space

01:03:44 to be in a ventilated protected space and

01:03:45 and in this case it was the lobby as opposed to the stair so the

01:03:52 so the actual

01:03:53 actual performance that's the wrong word the operations of the fire brigade on the night

01:04:01 night of or of the fire incident would have been different to what would have been set out in the actual guidance and the guidance changed

01:04:12 and the guidance changed and the acknowledgement of the two crews was different to the original concept for grenfell tower the two crews followed the 9 11 incident

01:04:23 two crews followed the 9 11 incident my understanding is having spoken to firemen for many many years and read the reports post 9 11 in that the temperatures that were reached the

01:04:35 the the crew that fights the fire is effectively protected by the second crew and i'm sure this has been explained to the panel by spraying above their heads so the hot gases don't affect them

01:04:47 so the hot gases don't affect them because as good as their suits are from temperature wise they were in london anyway at one time known as boiling the bag suits because they they don't wick the

01:04:58 because they they don't wick the temperature from the body and the perspiration so post-911 it was established that probably the maximum a firefighter at the face of a fire could withstand from

01:05:10 the face of a fire could withstand from a

01:05:10 a uh

01:05:12 uh durability point of view not only from heat but exhaustion as well was about 17 minutes so obviously the crews need to be given additional protection etc um sorry i've gone off a tangent all right

01:05:25 sorry i've gone off a tangent all right i

01:05:26 i invited you to um but yes i think i understand i mean i think what you're telling me is that the um

01:05:34 the um it would have been good practice for building control to have asked for a demonstration with other doors open yeah even though you don't think it's likely to have made any difference

01:05:45 to have made any difference i thought

01:05:46 i thought but i would i wouldn't couldn't get a correctly saying that the other aspect that is in my mind when you're adopting a flow criteria taken from

01:05:57 taken from that particular bs is that that recommends that you do consider other doors being opened so whether or not it would have a practical

01:06:08 whether or not it would have a practical effect

01:06:09 effect others more qualified should give the definitive answer but i did note when looking at the draft document

01:06:19 document which is in the bsem 101-6 series

01:06:24 series which i think is 13 which

01:06:29 which reflects this type of system there was a my reading of it and it was only a draft no recommendation for additional doors on other levels being open to be

01:06:41 on other levels being open to be considered all right well thank you very much

01:06:44 much yes mr scrooge for the transcript we can um

01:06:48 um i'll just give you the reference it's clause

01:06:51 clause 12.2.3.3 of bsen12101-6 which is

01:06:58 rbk3045054 at page 73 um there's a list there of the different door opening scenarios that should be um should be opened during the test

01:07:11 should be opened during the test for a pressurization system for a pressurization system um i just want to ask you about one particular scenario so where a door to the fire flat is open and a window in that flat is broken or

01:07:24 and a window in that flat is broken or is otherwise open um can you help us on whether the exposure of the system to outside air through the window would negatively affect the two meters per second flow

01:07:35 affect the two meters per second flow rate at the stair door no i can't help you i i i'm not qualified to make that judgment would you expect a reasonably competent bcb to have required the commissioning process

01:07:47 have required the commissioning process to have demonstrated that in that scenario the two meters per second was still achieved

01:07:59 a competent bcb

01:08:02 with a basic knowledge of fire

01:08:07 of fire would

01:08:09 would i think be expected to know that a window to a flat could be open

01:08:17 open or that the fire may and it doesn't happen in every case cause a window to fail

01:08:27 in the context of the door being open

01:08:35 the safety of the residents that would have been a transient risk because that door should have closed after them and therefore protected

01:08:47 and therefore protected everybody else using that same level it may have marginally if the window was open or failed been another leakage path but it would have been directing the fire and the heat out of the window

01:09:01 the fire and the heat out of the window so been a

01:09:03 so been a balance i would imagine i'm not qualified to give you the full scientific facts on that

01:09:12 on that mr hansen said in his oral evidence that he expected that door testing would be done to the british standard which is the standard we've just discussed which refers to the different door opening scenarios

01:09:22 scenarios and for the transcript that was day 154 page 197 lines 12 to 15. was it reasonable for mr hampton to make that assumption without seeing positive

01:09:34 that assumption without seeing positive evidence that it had in fact been done

01:09:38 no a wise man once said to me is unsafe to assume anything

01:09:45 when you say that guidance to which we've just been referred refers to a pressurization system are we

01:09:54 are we to think of pressurizing the staircase in this context a pressurization system is different to what was proposed

01:10:07 different to what was proposed you would pressurize the stair you would pressurize the lobby and you would pressurize the lift right

01:10:14 and it's as i hope i've illustrated it's a very um

01:10:20 um delicately balanced system therefore if you open doors on other levels well that then it's going to affect it that's what i was wondering you see the

01:10:30 the sen12101 is concerned with pressurization systems and you're applying it to a staircase and pressurizing the staircase then

01:10:42 and pressurizing the staircase then it would not strike me as surprising that if you open doors in the several places on the staircase you're likely to affect the pressurization because you're uh offering exit paths for the

01:10:55 uh offering exit paths for the for the pressure so to speak rather crudely but i think you'll understand but that wouldn't apply to the system that we're considering would it in my understanding of the system no it

01:11:07 in my understanding of the system no it wouldn't

01:11:11 to be quite honest is something because we know that the doors will be propped open by the brigades hoses that we generally look to demonstrate i can't honestly say i've ever seen a system

01:11:23 honestly say i've ever seen a system fail because of it i've i know anecdotally of a pressurization system failed when somebody cut a socket for the cleaners hoover

01:11:31 hoover in the actual wall of a protected shaft is that finally balanced right thank you very much so we know that the two meters per

01:11:43 so we know that the two meters per second was the performance criteria for this system so focusing on that rather than

01:11:48 than pressurization depressurization for a moment

01:11:52 moment and that was proposed on the basis that it would have been adequate to ensure so that it would have ensured an adequate means of escape

01:12:03 ensured an adequate means of escape how is it

01:12:04 how is it that

01:12:05 that the bcb would know that that adequate means of escape in the form of that flow rate would always be achieved depending on all these different scenarios unless it was tested

01:12:21 they wouldn't um

01:12:25 the design engineer would have carried out his calculations on the basis of

01:12:34 the information given to him and what he observed on site etc

01:12:42 that design is then given to others to build

01:12:46 build to formulate

01:12:50 tolerances etc may not have been maintained until that system is up and running whilst everybody's fingers are crossed it will follow the design intent

01:13:01 it will follow the design intent until it's actually tested and it's shown at the commissioning that everything is literally joined up and doing what it's supposed to do in the various scenarios is required to

01:13:13 in the various scenarios is required to address

01:13:14 address then nobody knows that it's actually working and achieving that particular flow rate

01:13:22 so it would then be important to check whether the two meters per second was maintained with other doors on the floor below for example open to the stair even if in principle you are skeptical that it

01:13:34 in principle you are skeptical that it would make a difference it's important to test it to make sure yes

01:13:41 it's good it's best practice shall we say

01:13:48 on the issue of um the force of the door you note at paragraph 257 of your supplementary report that there's no record of mr hansen measuring the door opening for us that's on page 64.

01:13:59 opening for us that's on page 64. correct in his evidence he said that the commissioning report didn't include the readings of door opening forces and said that building control were relying on the professionalism of the installer and designer was that a reasonable approach

01:14:11 designer was that a reasonable approach for the building control to take if he hadn't seen any records that he had the force on the doors had been tested no it wouldn't did not

01:14:22 did not somebody from js wright say that they

01:14:27 they with mr hansen no they tested them and recorded them and it was no more than 85 newtons and that mr hansen relied on his being

01:14:38 and that mr hansen relied on his being able to open the door without any undue force i think was the way it was phrased

01:14:48 i think that was in mr white's um

01:14:52 um evidence

01:14:53 evidence oral evidence yes so where where that had happened um was that sufficient for building control's assessment of whether the system

01:15:05 system was adequate and compliant i'll be quite blunt it was fine until you get found out then that's just a fact that is why you should record these things or get

01:15:16 should record these things or get somebody to recall them and submit that detail to you or get them to perform the test and you witness it and get them to record it and copy it to you

01:15:29 moving on to the topic of dampers uh in his evidence mr hansen said that he just considered b1 and b5 and did not consider how the system would in any way affect internal fire spread or building

01:15:41 affect internal fire spread or building compartmentation was that in your view a reasonable approach for him to take no it was not b1 and b5 rely on all other aspects or other requirements of the building

01:15:52 other requirements of the building regulations under part b and does that feed into your overall conclusion that the final certificate should not have been issued correct

01:16:03 mr hanson said that he considered the basic specification for the dampers to make sure that they were appropriate and he told the inquiry that the type of damper being used was a smoke control damper because it was being used to

01:16:15 damper because it was being used to control smoke and it did he said he believed and the references for the transcript are day 154 page 204 line 2 today 154 page 205 line 7.

01:16:27 line 2 today 154 page 205 line 7. was that level of scrutiny of the dampers by building control appropriate in your view no the damper required fire resistance to perform the function of the protected shaft

01:16:37 shaft a firefighting shaft it was critical particularly in context of b5 as i've said in my report it's the last

01:16:47 last way a firefighter at risk can evacuate the building it is the point of retreat for them they fall back to it and they

01:16:58 and they evacuate people via the shaft if they need to by rescuing them the inquiry heard evidence from mr jones of the damper supply gilbert's to the effect that the series 54 dampers were

01:17:10 effect that the series 54 dampers were not intended to be nor were described as being smoke control dampers the inquiry also has seen product documentation that reference test standards applicable to fire and fire smoke dampers not smoke control dampers

01:17:23 smoke dampers not smoke control dampers and mr jones also acknowledged that the series 54 damper had no formal certification at all would you have expected a reasonably competent bcb without the benefit of a mechanical and electrical engineer to

01:17:35 mechanical and electrical engineer to recognize that the dampers were not a smoke controlled emperor yes because they should have asked for full details of the damper and the book should have asked for the test results for the damper

01:17:48 for the damper so was it reasonable then for mr hansen to conclude that the damper being used was a smoke-controlled damper to put in inverted comas there just because it was being used to control smoke

01:18:00 smoke no because it had two functions fire resistance and smoke

01:18:08 can we just look now at a change in the design after kind of

01:18:14 kind of intervene to ask you how you're getting on um i was going to ask this question and then propose a break um because i'm not going to reach the end of my question no no before yes you take your calls um before the

01:18:26 take your calls um before the transcriber needs a break um so

01:18:30 um so yes i'm just asking you about this change to the design which we can see described in mr mani's first witness statement which is psb one three two nine page eleven

01:18:46 and it's sub paragraph three there in this part of the statement mr mani is explaining some of the key changes in the design that occurred as the technical submission progressed through the project and as we know there were

01:18:58 the project and as we know there were six revisions to that technical submission he says there that as well as the configuration of the extended smoke shafts and other detail which was finalized after the initial design work recorded in revision one of the

01:19:10 recorded in revision one of the technical submission was the specification and location of the fan sets used in the system and just to summarize what he says there is that initially it was envisaged that

01:19:21 is that initially it was envisaged that the north and smoke north and south smoke shafts would be connected at the roof level that design then changed

01:19:32 and a new arrangement was reflected in revision 5 of the technical submission onwards

01:19:38 onwards which he also confirmed with js wright was that change in design something that should have been considered by building control given that it post dated the rev 3 technical

01:19:50 that it post dated the rev 3 technical submission

01:19:54 yes i would have expected

01:20:00 building control to have been advised of a change in the design

01:20:06 even if it was simply to allow them to check it out on site when they were conducting their inspections you could turn up look at something say well that's what we approved and that's what you've got on site

01:20:18 what you've got on site what happened in between

01:20:25 thank you mr chairman that would be an appropriate good point right thank you very much um wellness mrs will time for a break for the morning and we'll stop now we'll resume at 25 to 12

01:20:36 we'll stop now we'll resume at 25 to 12 please and as with everyone else please don't talk to anyone about your evidence while you're away okay thank you very much

01:20:51 thank you 25 to 12.

01:38:01 would you ask mrs mendes to come back in please thank you

01:38:14 all right spencer's ready to carry on thank you good thank you yes grogan thank you

01:38:19 thank you we're moving on to commissioning now uh in his evidence mr hansen explained that he looked at the system's commissioning certificate as best he could but that not being a mechanical and electrical engineer

01:38:30 and electrical engineer um

01:38:33 the commissioning certificate is not something that he could interrogate as well as a mechanical and electrical engineer could do he also explained that with the loss of the mechanical net

01:38:45 the mechanical net mechanical engineer we weren't expected to go down and witness commissioning or any kind of inspection and the references for the transcript for that are day 154 page 49 line 25 and

01:38:58 for that are day 154 page 49 line 25 and day 154

01:38:59 day 154 page 147 lines 11 to 13. how common was it for building control bodies

01:39:06 bodies to employ an m e engineer at that time so the 2012 to 2016 period probably not common um i think as mr hansen alluded to

01:39:19 i think as mr hansen alluded to when the glc was disbanded the

01:39:23 the breg the building regulation electrical engineers

01:39:26 engineers group um was dispersed as were three surveyors and various ones went to all the london boroughs and as time went by they either moved on

01:39:37 and as time went by they either moved on or they retired and due to

01:39:41 due to mostly

01:39:43 mostly uh cost cutting um they

01:39:47 um they but their positions were not replaced also with the sorry if i may add with the loss of the section 20 a role disappeared now that went into

01:39:58 a role disappeared now that went into the building regulations to an extent but whereas under the protocol that was adopted by the glc for section 20 when break went out and

01:40:09 section 20 when break went out and periodically witnessed the testing etc of fireman's lifts firefighting lifts whatever you want to call them and

01:40:19 and safety lighting smoke control systems and the like that was no longer done the government was a great pains to lift the burden deregularized deregulate

01:40:31 deregularized deregulate the legislation and put the onus on the person carrying out the work to achieve and display compliance

01:40:42 so against that background would you expect a reasonable bcb to be able to consider a commissioning report without the assistance of an m engineer

01:40:53 yes a reasonably experienced one in as much as what you don't gather from the commissioning that you expect to see you ask that's the role of building control is to question

01:41:05 building control is to question and to check things are as they would expect to demonstrate compliance could you just expand on that so in the absence of an m e engineer what would

01:41:16 absence of an m e engineer what would you expect a bcb such as mr mr hansen to do when it came to inspection and commissioning of the system um to

01:41:26 um to to if he wasn't the reason building control generally do not accept invites to go to commissioning because it's a very long lengthy process as i said before

01:41:37 lengthy process as i said before and all they're really interested in the results not how if you balance damper 55 and then tweak damper 62 you'll end up with what you want they're not

01:41:48 with what you want they're not interested in that they're just interested in the end results but looking at the commissioner's certificate you would expect all the

01:41:57 all the smoke detectors to have been

01:42:01 tested in as much as they were activated by artificial smoke to run to make sure that when they activated they opened the vents that they were required to open to close vents that

01:42:13 required to open to close vents that they were required to open etc you wouldn't be looking at for anything as regards the wiring other than to the commissioning certificate to say it was installed as required

01:42:28 uh so would it follow then that you'd expect the commissioning documentation to lay out in a fair bit of detail that all of the relevant things had been carried out

01:42:39 carried out yes what i would have expected is what was given to building control in the form of i think three separate documents i.e

01:42:50 documents i.e well it was four documents it was the partial commissioning certificate as they termed it which was for floors for and above because the lower floors weren't completed at the time

01:43:02 weren't completed at the time there was then a commissioning certificate that related to the building as a whole but it didn't say whether it tested

01:43:10 tested all the flaws at the same time and then there was a separate sheet without heading that

01:43:18 that was established was the flow rate readings and the

01:43:24 and the another

01:43:26 another sheet that was the environmental flow rate readings so i would have expected a a proper commissioning certificate to

01:43:37 a proper commissioning certificate to have incorporated all that information and not be a few a4 sheets stapled together shall we say

01:43:47 and on receipt of the a4 sheets stapled together as you describe it is there anything you expect you would have expected mr hansen to do

01:43:57 to do either say thank you very much i note the content and i'm satisfied or this is inadequate i expect to see x y and z neither of which i understand was

01:44:11 neither of which i understand was the response

01:44:14 a paragraph 291 of your report which is on page 68 you say that in your experience systems are generally demonstrated on site using do you want yourself on the screen uh no it doesn't

01:44:26 yourself on the screen uh no it doesn't uh need to come up on the screen um

01:44:29 um generally demonstrated on site using a cold smoke test and that's something you've mentioned earlier in your evidence and that while that wouldn't fully replicate an actual fire situation

01:44:41 replicate an actual fire situation it would be indicative and you say that this doesn't appear to have been suggested or undertaken can you explain to us exactly how it would work in practice

01:44:52 work in practice in a building such as grenfell which was occupied

01:44:55 occupied a cold smoke test yes you would gain permission from one of the residents to access their flat and then you would set off a cold smoke machine

01:45:05 machine it's a theatrical smoke machine generally smells like baby talcum powder really and it's just thick white smoke which is discharged from a small electrical canister

01:45:16 electrical canister electrical device and then you would open the front door

01:45:23 that would activate the smoke detection and then you would observe what happened to the smoke as the system did what it's supposed to do and it would give you an

01:45:34 supposed to do and it would give you an idea of the direction of flow towards the grills into the shaft away from the staircase it would in that particular case

01:45:43 case if you left it running long enough to fill the lobby or you could purposely fill the lobby of smoke see what was the uh situation in the dead ends that have been mentioned and just to

01:45:54 that have been mentioned and just to give an overall impression of what the system would do it's it doesn't reflect fully obviously the energized smoke from a fire but it will give you in fact even

01:46:05 fire but it will give you in fact even because it's cooler smoke and not as buoyant and not as active it will give you a better indication of the way that the system is pulling the smoke do you know what is the nature of the

01:46:16 do you know what is the nature of the smoke that's generated um off the top of my head now it's just what they use in the theaters i asked a question because i just wonder

01:46:27 just wonder whether it contains very fine particulate matter which

01:46:33 which sometimes is the way in which smoke detectors operator believe and if so where does all the where's all the particular matter end up it's you can breathe it it's safe to be

01:46:45 it's you can breathe it it's safe to be in and breathe because it's used in theaters and then the smoke detection would generally work on obscuration ionization um smoke detectors are frowned upon because they have a

01:46:57 frowned upon because they have a radioactive element in them so as soon as that beam in the head is obscured by the smoke the white smoke in this case then it will activate

01:47:09 it will activate all right thank you as far as i'm aware it doesn't the particulars can't be large because there's you don't walk away covered in white well that's rather i was wondering particularly if you were going to fill the whole lobby with smoke

01:47:21 going to fill the whole lobby with smoke no it it it gets extracted away what what is the best thing you can do is do a hot smoke test but obviously nobody wants to do one of those and set fire to it

01:47:33 do one of those and set fire to it you could demonstrate a proposal in a derelict building by doing a hot smoke test and there are descriptions of doing hot smoke tests but then

01:47:43 but then i'd say they're never done these days thank you

01:47:46 thank you and if a cold smoke test had been carried out would one have been able to look at the different door opening scenarios that we discussed before the break to see what the effect

01:47:57 before the break to see what the effect on the flow direction or the flow rate might be um yeah i don't see why not it would demonstrate what would be happening with smoke yes and could it help to identify whether there were

01:48:08 help to identify whether there were breaches in compartmentation up through the dampers in the shaft it would have been a good way to observe it what you'd what has been done in past if you suspect there is a failure in

01:48:20 suspect there is a failure in compartmentation you would put colored smoke in

01:48:26 in an area and see if you could see it on the other side of the compartmentation that's been done that's to demonstrate whether it's good or bad compartmentation

01:48:36 mr hanson said that he was not aware that carrying out a cold smoke test is important in any system where there are extended travel distances although he accepted it could be a useful guide and

01:48:47 accepted it could be a useful guide and mr partler said that he would have considered a cold smoke test to be dangerous in an occupied building in light of that evidence are you still of the view that a cold smoke test should have been considered and

01:48:58 should have been considered and undertaken i think it would have been reasonable to consider it i've never heard of it being an issue in an occupied building do you think the question is not whether it would have been reasonable to do it

01:49:10 it would have been reasonable to do it but whether it was unreasonable not to have done it

01:49:18 i think in this particular particular case it would have been reasonable because you had an existing situation existing layout and construction of which you did not know all the intricacies and the voids etc

01:49:31 intricacies and the voids etc did the failure to carry it out for below the standard that you would expect of a reasonable bcb the failure to request that it was carried out

01:49:46 i think i'm going to say yes in this particular case yes particularly with an experienced bcb

01:49:55 one of dr lane's concerns about the system is that it may have drawn smoke from the fire flat into the lobby should that issue have been considered by the bcb yes um however i would say that in my

01:50:08 yes um however i would say that in my view it's inevitable if you extract from the lobby you will at some point draw smoke from the fire flat the cold smoke test would have indicated

01:50:19 the cold smoke test would have indicated whether that was excessive or not

01:50:26 moving on to a topic that you've already mentioned which is the the makeup error and the additional event proposed by mr hanson

01:50:35 hanson if we go to your report at page 68

01:50:42 paragraphs 296 and 297 you say there

01:50:50 that you are not satisfied that the issue of the makeup or input error in the ground floor entrance was resolved and you conclude that the commissioning report did not relate to the system as installed and as such the commissioning

01:51:01 installed and as such the commissioning report should not have been accepted as part of the evidence of compliance that resulted in the bcb issuing a building regulations completion certificate and you give the date there this relates to as you've identified the

01:51:14 this relates to as you've identified the the suggestion by mr hanson that an additional event be added after the commissioning had been undertaken and then no additional commissioning process was carried out

01:51:28 in those circumstances where the bcb suggests

01:51:32 suggests a change to the system what further commissioning would you expect to have been undertaken after that the whole system to say that everything had any additional connections to other

01:51:43 any additional connections to other parts that already had been commissioned um had been dealt with it may not have been to the depth of the original but as the lower floors had not had an

01:51:54 but as the lower floors had not had an in-depth commissioning undertaken because the available commissioning report only related to the flaws above the lower levels

01:52:05 the lower levels there was no overall commissioning report that related to the building as completed

01:52:11 completed can we go to mr hanson's evidence on this in the transcript which is day 154 page 160

01:52:27 and it's line 15 there

01:52:30 there he's asked do you want to just clarify exactly what was being requested by building control and he says yes okay so after witnessing of what i call sequence testing and then he explains what that is

01:52:41 is um

01:52:43 um there was a lobby there which was existing that didn't have any ventilation at all so just a little bit of background on this he says generally speaking if i see something that could be improved in the building i mention it to the design team

01:52:54 to the design team [Music]

01:52:56 [Music] and then

01:52:58 and then we see that again sorry i think the reference i've got for this is wrong um but what mr hansen's evidence was if i can summarize

01:53:09 i can summarize is that this wasn't something that he could legitimately ask for as a matter relevant to compliance it was an improvement that he was suggesting

01:53:19 um in light of that evidence is it still your view

01:53:23 your view that an additional commissioning process should have been carried out yes because although it may have been a suggestion on his part it was adopted and therefore affected

01:53:35 it was adopted and therefore affected the system as finalized

01:53:43 just a few we've just got two topics left the first one is the involvement of the london fire brigade again on the commissioning we've covered the consultation with the

01:53:55 we've covered the consultation with the london fire brigade in module one these questions relate specifically to the commissioning and testing if we could first go to the 2015 sca guide at page 56 which is

01:54:07 2015 sca guide at page 56 which is rbk402932

01:54:19 and under 9.1 introduction the text says as smoke control systems are primary life safety systems and or for assistance to the fire and rescue services it is imperative that the smoke

01:54:31 services it is imperative that the smoke control system is tested by the installer and then offered for witness testing to the authority having jurisdiction to prove its compliance with the project specification and the approved design criteria

01:54:43 criteria authority having jurisdiction is defined on page nine of that guidance

01:54:51 so if we go there

01:54:56 and you'll see it's the first one the organization office or individual responsible for enforcing the requirements of legislation or standards or for approving equipment materials an installation or a procedure

01:55:08 installation or a procedure i just want to understand what your understanding of that guidance is is the authority having jurisdiction the lfb the bcb both neither

01:55:18 neither both

01:55:20 both the

01:55:21 the bcb under the building regulations and the fire authority either fire service the london fire brigade in this case and the fire safety order

01:55:32 safety order but you would do that any you would invite the local fire service as well because it's familiarization they're the ones that are going to turn up and fight the fire it's in your interest for them

01:55:44 the fire it's in your interest for them to know how that particular system works does the fact that the lfb witnessed the commissioning of the smoke system on the 28th of april 2016 have any bearing on your views about

01:55:57 any bearing on your views about rbkc's approach to the commissioning process no so would it have been reasonable for the bcb to rely on the fact that the lfb had been there and hadn't raised any objections

01:56:08 objections um

01:56:12 i wouldn't have expected the lfb to make any comment on their witnessing the commissioning unless it was their opinion that there was something

01:56:23 their opinion that there was something wrong with the system from their operational point of view or otherwise the final topic that we have to cover is the gas works in 2017 so we're moving on

01:56:34 the gas works in 2017 so we're moving on now from the refurbishment to the gas works you covered these in your first report and for the transcript that references bmer 604 page 156

01:56:45 that references bmer 604 page 156 onwards

01:56:48 onwards i want to look at the advice given by mr allen

01:56:51 allen to janice ray of the tmo about whether the gas works were controllable under the building regulations so if we could go to tm012016546

01:57:03 page three which is the beginning of an email chain on the matter you see at the bottom there miss ray tells mr allen that the new riser has been sorry uh mrs

01:57:15 that the new riser has been sorry uh mrs ray tells mr allen that national grid is fitting a new riser to grenfell and they've told her that building regulations approval is not required she asked him to confirm that this is

01:57:26 she asked him to confirm that this is correct and if we go further up the page we see

01:57:29 we see that on the basis of the information she gives him

01:57:32 gives him he agrees that the work is repair providing

01:57:35 providing that no change to fire safety implications um are there and so no application would be required so he says i'm content that this work will be regarded as a repair

01:57:47 will be regarded as a repair with that caveat and it's right you agree with the initial advice he gave based on the information he received from janice ray on the basis it was a repair of an existing installation yes

01:57:59 existing installation yes going up to page two of the same

01:58:04 document we see another email you can't see the date on that page because it's on page one but the date of the email is the 24th of march 2020 so we've moved forward in time a little

01:58:15 forward in time a little ms ray tells mr allen that the new riser has been installed in a new location and if we go up to page one

01:58:24 we see an email at the top on the 3rd of april 2017 from mr allen where he advises that they do not usually take a building

01:58:35 they do not usually take a building regulation application for this type of work and he would still regard it as a repair

01:58:40 repair and in your report your view is that the installation of a gas riser in a new location was controllable under the building regulations yes

01:58:50 yes and that's because the venting of the gas pipe duct into the stair was detrimental to escape and affected the integrity of the stairs a firefighting stair

01:58:59 stair yes the riser had been moved in its position it had been installed within the stair

01:59:08 by virtue of it being a gas riser it would be in a position whereby it would ventilate any leak that emanate him from the steel conduit that it was made of

01:59:19 made of the purpose i understand from speaking to gas engineers prior to

01:59:26 prior to this inquiry and subsequently is that they want people to be able to smell the gas

01:59:35 positioning in the only escape stair from a tall building by any stretch of the imagination i don't think would be acceptable

01:59:46 don't think would be acceptable the fact that it is the intention that it is for people to sniff the gas basically underwrites the fact that it's expected that it will at some stage leak

01:59:58 expected that it will at some stage leak and to have a combustible gas in the only escape route and the fire fighting shaft

02:00:04 shaft is very bad practice it is also governed in my view under the building regulations in that this is an adverse effect on the existing arrangements and

02:00:15 effect on the existing arrangements and is therefore a material alteration and potentially a false foul of the non-worsening principle it does yes so what you're saying is the building regulations

02:00:28 the building regulations which are

02:00:29 which are which impose legal requirements would uh be inconsistent with putting the riser where it was relocated

02:00:38 relocated the building that's a question of law i suppose but uh well

02:00:44 it would be in my view the works as undertaken made

02:00:49 made the situation worse in respect of fire safety that invoked the building regulations by a worsening of the situation

02:01:00 that meant that the building control body would require

02:01:07 an application with proposals that would justify it where it was if you like this is after the event because it was put in um and then you would look at the

02:01:18 um and then you would look at the guidance

02:01:19 guidance in relation to gas installations in buildings having regard to the fact this was an escape stair and that it was a firefighting shaft

02:01:33 and that it was a firefighting shaft now adb

02:01:35 now adb is not the most straightforward as regards the installation of gas in a stair

02:01:40 stair and it effectively says you can install it

02:01:44 it if you

02:01:46 if you have it in a conduit a gas pipe that complies with the gas safety regs x y and z it then says if you enclose it

02:01:57 it then says if you enclose it for athletic or other reasons you have to vent it top and bottom

02:02:03 positioned in this excuse me positioned in the stair it was not ventilated top and bottom and it was enclosed it was only ventilated at the top as i understand it unless it was ventilated into another

02:02:15 unless it was ventilated into another escape route i.e the escape route from the stair at the bottom but also all the guidance in relation to a firefighting shaft says you shall not have any service within

02:02:27 you shall not have any service within that shaft that is not related to the functioning of the firefighting shaft if you enclose the gas riser

02:02:39 you effectively impact in practice or otherwise take it out of the fire fighting shaft but you would have to take it out by construction that was imperfect and attained two hours fire resistance

02:02:53 and attained two hours fire resistance now

02:02:54 now the tmo was informed by the gas undertaker that they were going to enclose it when i went down to site it was partially enclosed because i think the fire occurred in the interim

02:03:06 in the interim but the protection was actually on the firefighting shaft side on the stair side

02:03:11 side where you would not expect the attack of fire to come from it should have been in my view on the inside of the stud that was separating the gas riser from the stair

02:03:26 so in effect to summarize your view um

02:03:29 um [Music]

02:03:30 [Music] what mr allen ought to have done was say this is controllable under the building regulations and therefore i need to see justification as to why these proposals are compliant

02:03:41 are compliant or no worse yes um

02:03:44 yes um i mean i think i think one of the first things he should have said to her yes it is controllable and i can tell you now it won't be acceptable if you're citing it in a fire

02:03:55 acceptable if you're citing it in a fire fighting shaft or it has been sighted in a fire fighting shaft then i would imagine and this is just to illustrate it she would have said but it's already in there and then

02:04:06 and then i think mr allen should have been saying words to the effect well in that basis if you're not going to move it then we expect it to be separated to the required to our standard from the stair

02:04:17 required to our standard from the stair the inquiry's gas expert mr hancox gave evidence that mr allen's advice as contained in that email was a common position taken by bcbs and the reference for that is day 161 page

02:04:30 the reference for that is day 161 page 21

02:04:31 21 line 18.

02:04:33 line 18. is this an issue then on which there might be a range of reasonable expert opinion from the building control side of things

02:04:43 i i don't know if mr hancock was actually referring to buildings of this height with that contained firefighting shafts but a

02:04:53 but a reasonably competent building control surveyor shouldn't have known that a firefighting shaft by virtue of the recommended standard shouldn't have

02:05:04 recommended standard shouldn't have anything in it that did not support the functioning of the firefighting shaft if we perhaps just go to his evidence so you can see what he was

02:05:15 his evidence so you can see what he was asked and what his response was it's um as i said day one six one page 21.

02:05:30 and it's there like line 18. in 2016 would a gas engineer have expected their work on a replacement riser to be controllable work under the building regulations and subject to building control approval and

02:05:42 subject to building control approval and he says no

02:05:46 does he mean by replacement like for like

02:05:53 i.e same service in the same position

02:06:01 we can we can check that um to see what it the base of which the question was put to him are you aware that this issue prompted so the works that we're actually looking at

02:06:13 the works that we're actually looking at so the installation in a stair in a tall building would have prompted a different range of responses from different bcbs i know it should have prompted it is

02:06:24 i know it should have prompted it is controllable

02:06:29 i suspect there are some that would not have had that reaction on the basis that it is permitted if you like under the

02:06:40 is permitted if you like under the guidance within adb subject to certain conditions

02:06:47 but where you have a firefighting shaft you have that additional consideration it is an issue this aspect of venting gas

02:06:59 gas supplies

02:07:00 supplies just by way of illustration i was looking carrying out a risk fire risk assessment in a conversion from the 1980s

02:07:10 1980s of a rather large in its day very grand house that been converted into small flats in the 70s and the time had come to replace the gas supply

02:07:21 supply and the

02:07:23 and the one staircase the gas engineer as i was

02:07:29 as i was when i got to the place was in fact venting

02:07:32 venting the gas supply into the main entrance hall in the ground floor taking the pipes then into a riser and up to the top venting at the top and venting into the hall below

02:07:44 venting into the hall below which was obviously in my view well in my view was unacceptable and so the arrangement was changed

02:07:55 but i think there is a con a belief that if a an accredited gas contractor undertakes the work everything will be fine

02:08:07 everything will be fine people

02:08:08 people quite rightly are somewhat scared of gas because of the it goes bang on occasion but

02:08:17 but in the context of fire safety under the building regulations it is a recognized phenomenon we know it occurs we know it goes into stairs

02:08:28 goes into stairs we have standards that go with that if you deviate from those standards or you want to enclose it aesthetically there are further standards but there are additional standards that relate to a firefighting shaft

02:08:41 a firefighting shaft so would it have been reasonable for the bcb to take any comfort from the fact that the gas transporter in this case cadent was ultimately responsible for those works

02:08:53 um not on the basis that they were not compliant with the standard required at the time

02:09:00 the time um the the actual installation of the gas may have been perfectly okay its location and its its location within the firefighting shaft was unacceptable

02:09:12 shaft was unacceptable did cadent know it was a firefighting shaft i don't know you say you consider that a building notice would have been reasonable um but that some authorities would have

02:09:23 um but that some authorities would have required a full plans application yep the reason for that is that the building regulations and the rro legislation require that where

02:09:35 legislation require that where a building is or will be subject on completion to the rro then a full plans application is the only route under the building regulations and that is to ensure that

02:09:46 regulations and that is to ensure that the necessary consultation takes place in a quite formal manner however

02:09:55 however that requires quite a process a building notice with a simple description would have achieved the same function because in my opinion the answer would

02:10:06 because in my opinion the answer would have been no you can't put it there so

02:10:10 so there was

02:10:10 there was effectively no need to consult the fire service because the answer from the building rex aspect and the bcb enforces the building regs the answer was no it shouldn't be

02:10:21 regs the answer was no it shouldn't be there

02:10:23 there but

02:10:24 but i can quite understand any other building control body say no we require a full planned application and strictly as a matter of the regulations because

02:10:35 as a matter of the regulations because this was a building that would be subject to the rro it should have been a full plans application yes um yes in the context it was adversely affecting the existing fire safety

02:10:46 affecting the existing fire safety arrangements yes and it was a material alteration yes thank you miss menzies that's the end of my prepared questions for you so now would be a time for a break to see if anything else has come in right well

02:10:58 if anything else has come in right well as you

02:10:59 as you already know i'm sure mr lindsay's we have to have a break now to enable council just to check that nothing's been left out and to enable others who are not present in the room to suggest questions

02:11:10 present in the room to suggest questions that perhaps we should put to you so we'll we'll break now we'll come back at 25 past 12 and see if there are any further questions okay thank you thank you very much we'd like to give the usher

02:11:28 all right 25.00

02:25:58 all right you got some spencer's to come back in please

02:26:11 right well let's see is there any more questions shall we yes mr grogan uh thank you um we do not think there are any further questions that we need to ask right at this stage good all right thank you very much well

02:26:24 good all right thank you very much well miss menses it really just remains for me to thank you very much yet again on behalf of the panel and the inquiry as a whole for uh all the work you've put into your expert reports and of course

02:26:35 into your expert reports and of course coming here today and yesterday to give us your oral evidence i mean i need to hardly say we're very grateful to you it's been a pleasure very helpful and very interesting and

02:26:46 and so we're going to profit greatly from what you've told us okay i hope so thank you very much indeed thank you bye-bye thank you of course thank you

02:27:03 well thank you very much ms grogan um that was our last witness for the day so we're going to call a halt at that stage and uh that will complete the inquiry's

02:27:15 and uh that will complete the inquiry's hearings for this month we shall not be sitting during august but we shall resume at 10 o'clock on the 6th of september

02:27:27 on the 6th of september thank you thank you very much

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