Building Regs requirements

[Davey]

Good morning,

We've received planning permission for our small (3m x 3m) single story kitchen extension. We're going for a full plans application and the architect has sent us the first draft of the drawings to be submitted for Building Regs approval.

I'm going to give him a call on Monday but just wondered if anybody could confirm the following:

1) The drawings show two new mains powered interlinked smoke alarms and a heat detector added to the existing structure. Is it a requirement to upgrade the existing building when a new extension is built?

2) Powerpoints and lightswitches to be between 450mm and 1200mm above FFL. Does this apply to extensions? We would like the switches and sockets at the same height as the existing ones if possible?

3) A Tyvek sealed cold roof system with closed eaves is shown. This isn't something I've heard of before - is it a common method of construction?

Thank you

 

[freddiemercurystwin]

1) Not usually.
2) They can be at levels to match the existing.
3) Tyvek is a breathable membrane so allows air to pass through it so no need to have physical vents at the eaves in a typical roof that has felt that is impermeable.

 

[Davey]

Thanks FMT

Spoke to the architect yesterday and he said the interlinked alarms are required by our local authority building control. TBH I think I'll just take his word for it - the alarms are not a bad thing and shouldn't add too much to the cost (although we are watching every penny!)

I would have expected the architect to know the regs about the height of power points and light switches would not apply but I didn't bother asking him about this. It's a kitchen extension and I suddenly realised all sockets will be above the work surfaces and we're using the existing light switch for all lighting

Tyvek roofs seem fairly common for extensions - presumably a simple way of meeting the required U-value?

Thanks again

Davey

 

[^woody^]

You'd need interconnected alarms for a three story [loft] conversion, but otherwise a just a new detector for any new landing but it can be independent

Unless something has changed very recently?

 

[freddiemercurystwin]

Aye I've had numerous extension plans approved without linked smoke alarms in the rest of the house.

Breathable membranes in roof's have no effect on U Values they are simply a means of avoiding of traditional vents at eaves and ridges.

 

[Davey]

Mmmmm thanks Guys,

The drawings have now been submitted for approval but it seems my architect is a little over-zealous...

It's a 2 story house and we're having a single story extension to enlarge the kitchen. The architect has specified smoke alarms in the hallway downstairs and on the landing upstairs. Also a heat detector in the kitchen.

Not necessarily a bad thing I know but we are trying to save the pennies.

If the drawings are approved showing the alarms, when we come to do the electrics is it too late to persuade the Building Inspector that we've changed our minds?

Thank you

Davey

 

[^woody^]

You only need to conform to the b/regs. So even if the approved drawings show something which is not required by the b/regs, then you don't have to do it

 

[garyo]

Aye I've had numerous extension plans approved without linked smoke alarms in the rest of the house.

My electrician seemed pretty insistent that I'd need a new linked smoke alarm on my landing (next to my 2 storey extension) and heat detector in my kitchen. This could possibly due to the fact that the kitchen is at the bottom of the stairs (i.e. the "escape route") and there isn't a closable door separating kitchen from stairs?

 

[Davey]

Thanks again Guys

My electrician seemed pretty insistent that I'd need a new linked smoke alarm on my landing (next to my 2 storey extension) and heat detector in my kitchen. This could possibly due to the fact that the kitchen is at the bottom of the stairs (i.e. the "escape route") and there isn't a closable door separating kitchen from stairs?

Our kitchen is also at the bottom of the stairs but we do have a closable door.

You only need to conform to the b/regs. So even if the approved drawings show something which is not required by the b/regs, then you don't have to do it

I think I'll see how much it will cost to get the alarms installed (and how much money we've got left!) when we get the electrician in.

If its too expensive and/or we can't afford it I'll tell the Building Inspector we've changed our minds.

Regards


Davey

 

[freddiemercurystwin]

there isn't a closable door separating kitchen from stairs?

That'd be why then, usually there is a door.

 

[ianc1200]

When Approved Document B changed in April 2007 it became a requirement for 2 storey extensions, and where a ground floor habitable room was created without an external door. Loft conversions & houses already required it. For these purposes, kitchens were classed as habitable. Some authorities do go beyond this and require SD's in other situations - IMO going beyond the recommendations of Part B.