insulation issues with extension / conversion

[mumbles78]

Hi everyone,

Picked up loads of helpful advice from the forum before but this is my first post so go easy. I'm hoping someone might be able to help me out with an insulation issue I'm having with my current project.

My house has a garage which is separated from the house by an unheated covered passageway. I'm now in the process of extending the back of the house for a new kitchen and utility room and as part of this the passageway will become part of the main house and will be fully insulated and heated. The garage wall will therefore become the new external wall to the house.

The existing garage wall is a single skin of brick. My question is how best to insulate it. My current plan is to insulate the inside of the garage with 100mm of kingspan/celotex between batons and then fix OSB on top. However, I'm not sure what the requirements would be for damp proofing, fire regs for the use of OSB in a garage and I have no idea what air gaps would be required.

Any advice would be fantastic,

Thanks.

Matt

 

[freddiemercurystwin]

Insulating on the inside would be better, thermally speaking. And easier too, just add insulation+plasterboard.

 

[mumbles78]

Insulating on the inside would be better, thermally speaking. And easier too, just add insulation+plasterboard.

Thanks for the response Freddy. I guess you're right but I was trying to avoid that option (insulating in the passageway) as it will really constrain the usable width. I will have another look at it though. What's the thinnest type of insulation which still complies with building regs?

 

[ban-all-sheds]

Insulating on the inside would be better, thermally speaking. And easier too.

No and yes.

Thermally speaking external insulation applied to what are now the outer walls of a house with integral garage would be better.

Harder to do, but it makes the walls of the garage a thermal mass for better equilibrium, it avoids all issues with VCLs and possible interstitial condensation, it does not compromise fixing things to the walls and so on.