Insulating a single brick bathroom/kitchen extension

[riley]

Any advice as to the best way to insulate a single brick extension that will be used as a bathroom?
I was thinking battens, kingspan and plasterboard with a vapour barrier, but space is at a real premium, so are there better ways?
And can anyone recommend an electric underfloor heating system?

Thanks.

Adam.

[mattty]

Hi mate,

To achieve a decent level of insulation you need to accept the fact you are going to lose some space, or settle for a cold room.
I would dry line the room with 50mm metal stud, set 20mm from the brick wall and insulated with 50mm of kingspan.
Apply a vapour barrier and plasterboard, job done. It makes integrating the bathroom plumbing a lot easier too.

[nickw]

External insulation?

[modernist]

Why not consider a second leaf of blockwork with insulation bats in the cavity. If it's going to be used as a bathroom you are going to have to get a decent level of insulation or end up with discomfort and condensation.

[woodsmith]

Only fit electric underfloor heating if you have a lot of insulation under the floor. I fitted some to our, as it turned out, uninsulated bathroom floor and the cost of running it was silly.

For the walls I've done the same as Matty recommends to a couple of our rooms and it has made a big difference, not just to the warmth but another big benefit is that the inner skin ensures that you will not have any damp problems. The only thing I would add would be that, especially if the wall shows any sign of damp, to provide some ventilation between the wall and the stud wall, possibly by fitting some air bricks.

[riley]

Thanks for the help fellas.
Sounds like I now have a plan.
Merry Christmas.

Adam.