Building Regs (Roof extension implications)
Building Regs (Roof extension implications)
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jdw1234

Original Poster:

6,021 posts

239 months

Thursday 3rd November 2011
quotequote all
Gentlemen,

I recently started this thread about extending a terrace house (many thanks to everyone).

http://www.pistonheads.com/gassing/topic.asp?h=0&a...

It appears that you need to have a corridor from stairs to door.

Is there any way around this (thousands of london terrace houses have an open plan front room)?

If I have a wall taken back down after getting rubber stamped will house insurance be invalid in event of fire?

Many thanks in advance for any tips or replies.




mk1fan

10,860 posts

249 months

Thursday 3rd November 2011
quotequote all
With your proposals in mind. The Building Regulations require that the single means of escape route needs to be a protected route.

Now the common interpretation of this is that the route be enclosed but there are alternative methods of protection.

One being a domestic sprinkler system.

Another is to have a more comprehensive automatic fire detection and alarm system. I have two domestic refurbs on the go where we are doing just this to provide the 'protection'. The arguement being that the sooner a fire is detected, the less the building is on fire and the sooner occupants are alerted and leaving.

I've always found getting Building Control Departments to consider and approve 'alternative methods' more unpleasant than a kick in the crotch. So if you're wanting to try it I suggest you use an Approved Inspector to deal with the Building Regulation approvals.

Sam_68

9,939 posts

269 months

Thursday 3rd November 2011
quotequote all
jdw1234 said:
It appears that you need to have a corridor from stairs to door.

Is there any way around this (thousands of london terrace houses have an open plan front room)?
Potentially, yes.

In certain circumstances you can have 'escape windows' as an alternative (windows that meet certain criteria in terms of opening size, cill height and height above the ground, so that you can escape via them instead of via the 'protected stairwell').

You need to download Approved Document B to the Building Regulations for the full criteria.

Don't get optimistic too soon though: Sod's Law dictates that you'll have a bloody great purlin slap bang where you need to put your escape window or something. Handy tip on sill height, though: if you can't manage a low enough cill relative to your floor level, you can always put a fixed step underneath it .

Sam_68

9,939 posts

269 months

Thursday 3rd November 2011
quotequote all
Hang on; sorry!

Just read your link and realised you're talking about a 2nd floor loft conversion.

In which case you may exceed the 4.5 metres from ground to upper floor level for an unprotected stairwell and escape windows.

You still don't necessarily need a corridor from the stairwell to the door though: if the stairwell itself is enclosed, it can still be acceptable for final escape to be via another room, provided you have a choice of two exits at the ground floor. This seems as though it might be viable for the plans you've posted at the beginning of your linked thread.

If your upper floor isn't much above 4.5 metres above ground level, there may be a 'bring the mountain to Mohammed' solution of using escape windows but artificially raising the external ground level (being careful not to compromise your DPC) to bring it within limits.

mk1fan

10,860 posts

249 months

Thursday 3rd November 2011
quotequote all
Personally, I'd spend £300 on extra detectors.

Sam_68

9,939 posts

269 months

Thursday 3rd November 2011
quotequote all
As you yourself pointed out, that would depend on whether your BCO is willing to accept 'alternative solutions' though, doesn't it?

Personally, I'd rather stick to the Approved Documents rather than than get into having to prove a 'risk engineered' solution to an intransigent BCO, but either way it will depend on the individual circumstances of the OP's design.

mk1fan

10,860 posts

249 months

Thursday 3rd November 2011
quotequote all
Or work with an Approved Inspector.

Sam_68

9,939 posts

269 months

Thursday 3rd November 2011
quotequote all
The Building Regs are the Building Regs, whoever inspects the work, but in my experience, AI's tend to be more careful/stringent with interpretation of the Regs than many experienced LA BCO's.

They have their CIC registration and their PI premiums to worry about...

jdw1234

Original Poster:

6,021 posts

239 months

Friday 4th November 2011
quotequote all
Mk1, Sam,

I really, really appreciate your responses.

Good to get some thoughts from pros and good to hear a proper architect might be able to come up with a solution.

Thanks again guys.

JW

mk1fan

10,860 posts

249 months

Friday 4th November 2011
quotequote all
Sam, I've found the opposite. I much prefer working with an AI and - currently - they are significantly cheaper than Building Control too which is handy when discussing things with Clients!

ETA: Although, in fairness I've found the BC team at Richmond to be just like working with AI.

JW, we should talk.

Edited by mk1fan on Friday 4th November 13:13