Improving insulation to existing dormer conversion

[moonbug]

My house has a dormer conversion done ~40 years ago (I haven't dug out the original pp application to find the exact date). As a result it has very poor insulation. I'd like to improve the insulation, which I think should be as straightforward  as stripping the plasterboard and relining with PIR. 

My question is: if I do this, will that require building control approval? Will this change likely require me to bring other aspects of the conversion up to current building regs? (eg fire door, protected escape)

 

thanks!

 

M

[nod]

No you won’t need BC to improve the insulation and your 30 minutes fire resistance will stay the same 

Leave a small air gap and use a foil backed board 15 mil 

[Redbeard]

I am not yet engaged with AI except as a method of speeding up meat production, but here's what it says:

 

"Generally, upgrading room-in-roof insulation does require Building Control approval if more than 25% of the roof area is being replaced or re-covered, as this triggers the need to meet current thermal insulation standards. If the work involves replacing or significantly upgrading a thermal element (like a roof), building regulations apply, and you'll need to ensure the insulation meets the required standards. "

 

..and that's the line I have followed. Bldg Regs defines 'renovation of a thermal element' as 'adding or replacing a layer' (of an 'insulation sandwich')

[torre]

If you're renovating more than 50% of a thermal element (your roof) or 25% of the whole building envelope then yes, you do need building control, but as it's already a room then you won't be subject to other regs.

 

An advantage of getting building control involved is that because there's an official record any improvement should be reflected in an EPC if you sell. If that's not important then a lot of people would just get on and make the improvement for their own benefit.