Building Regulations Part B1 - Means of Escape - Loft Conversion

[Brian Downes]

My client has an existing single bedroom loft conversion on top of his two storey semi.
 Existing means of escape arrangements are ladder rescue by others from loft conversion window, accepted when development was carried out under previous ADB.
A new ground floor extension will obstruct the ladder pitch to the window, so BCO has deemed Loft conversion to be adversely effected, quite rightly.
Access to loft conversion is by a fully compliant full width staircase discharging onto first floor landing inside staircase enclosure. Staircase from first to ground discharges by front door. All rooms opening onto staircase have existing timber panel doors, close fitting, imperforate and held closed by latches.
I propose an LD1 AFD system as a compensatory feature achieving an alternative functional solution by giving early warning in lieu of the greater structural protection that would be achieved by the FD20 doors required by new ADB.
I can find no directly comparable situations amongst Building Regulations 'Determinations' posted on DCLG (or whatever they are called this week's) website.
My client spent many many hours stripping his doors and staircase so does not want to replace the doors with FD20 fire doors.
Has anyone had any experience of succesfully arguing a similar case?

Brian Downes

[kurnal]

Brian
Can you not upgrade the existing doors to an FD20 standard to the satisfaction of the BCO? Fire and smoke seals are available that are self adhesive and pin into the rebate of the door frame and intumescent varnishes and veneers if absolutely nescessary could be used to maintyain the appearance of the door. Suggest a look at the envirograph brochure (safelincs are agents) or the English Heritage website. If the staircase is enclosed to its full height there really isnt a problem and especially if you go for an LD2 alarm system rather than the LD3 standard, if the existing doors are in decent condition and a good fit I cant see any problem at all, without varnish etc

[Brian Downes]

Kurnal,
           Thanks for the reply but my client does not want to touch the doors in any way for aesthetic reasons, and the fact he spent weeks stripping them to achieve the result he has now, hence the AFD offered as a compensatory feature for retaining the existing doors.
Smoke seals and closers are no longer required by the new ADB on the FD20 doors enclosing a protected shaft in a dwelling so I saw no reason to offer these to the BCO.
Brian

[kurnal]

Hi Brian
I was coming at the problem from another angle. I think it is unlikely that the BCO will accept just an enhanced spec AFD on its own as a compensatory feature. But if you friend has taken time and trouble to strip the doors then I guess they are probably fairly substantial well made doors that would certainly offer some degree of fire resistance and probably maintain their integrity for long enough to allow persons to escape. I think to win this you need to show that the doors you have are equivalent to a FD20 door.

But we need to provide some evidence to justify this. Since the ADB does not require smoke or heat seals or a self closing device, it sets a low benchmark that assumes the premises are reasonably safe even if the doors are left open. So it is a matter of satisfying the BCO the existing doors provide an equivalent standard and there is a wealth of information to support this. Simple enhancements such as I suggested may convince them. Otherwise, one of the  free videos in the envirograph marketing package shows just such a door in a realistic fire situation, not a test furnace. BM Trada also have done many fire tests over the years  to support their document "fire resisting door sets by upgrading" and comparisons could be made with their data. The work done by many companies in conjunction with English Heritage may help.

[Brian Downes]

Kurnal,
           Thanks again for your advice, I was going to suggest upgrading with intumescent products if we hit a brick wall with the AFD.
Brian

[smudger29]

Hi all,

I'm close to completeing a conversion on a bungalow - some time ago my builder mentioned that I would need to upgrade the doors to fire doors on the first floor. I took this matter up with my architect who assured me I didn't as the drawings had been signed off by building control without them and that the usual loft conversion issues didn't apply here as it wasn't a second storey 'loft conversion'. I spoke with the buiding controll guy directly and it seems 20 min firedoors were suggested as an alternative to lowering incorrectly built dorma windowa -  six in fact with cill height around 50mm higher than specified on the drawing - a little detail my builder neglected to pass on!  

The bungalow was built in 1928 and has common 34mm thick  pine 3 + 1 panel doors downstairs - at the time the buiding work started I purchased some matching pine panel doors to  match upstair which untill last week I was told would bave to be scrapped. Building control told my builder that it was now possible to upgrade the doors I've bought but hasn't supplied spec's etc. I've done a little research and it seems I can do this by adding fire retardant material laminate to panels which which are around 8mm thick and painting the whole face of the door side that need protecting  with a fire resisting coating which can be over painted.

can somebody tell me if this is all that is required - there rules relating to Door closers and fire/smoke strips in the door closures seem to change regularly - what is the current requirement?

Clearly the builder made a mistake with the cill heights and I'll be discussing the cost of this door  upgrade with him but need to know exactly what we need to do to comply.

Thanks for the advice

[kurnal]

This sounds a bit of a tangled web!!
Presumably the height of the loft conversion floor is less  than 4.5m above any of the surrounding ground.
And just for the record  did work start on site before April 6 2007? (Not that this makes much difference in this case)
Means of escape
you should either have a staircase with FD20 fire doors protecting the landing and hallway - these do not need seals or self closer- or AS AN ALTERNATIVE window exits from each habitable room with a minimum opening of 450mm in any dimension with the sill not more than 1100mm above the the floor, the window to enable a person to lower themself to a place of safety. (If you have a conservatory beneath the window this will not do). See paragraph 2.8 of Approved document B 2006 edition- available for free download via the planning portal.(google)

The 1100mm rule is all about persons being able to reach the window cill to lower themselves out- 50mm is not really a significant variation on this but you could provide a step or rail inside?

Door upgrades- since you do not need self closers or seals on a domestic FD20 door, I would obtain a copy of the Envirograph CD which shows a door of the type you describe under an ad hoc test carried out by Avon Fire Brigade. The test did not replicate a BS476 test in any way but was under fairly realistic conditions. I would show the video to your building inspector and seek his approval.
I would then upgrade your doors to their scheme or similar. Safelincs,the sponsors of this site, are agents for envirograph products and may be able to help you get the CD catalogue.
But the step would save you doing this.

[jasper]

I had this on my house and unfortunately had to go down the fire doors with s/s and closers route - a real pain in the backside when moving from room to room with 1 baby or the other infant