Hi everyone. Our Edwardian house had a single story extension built in 1990, with 4 1/2" bricks (external & internal) with a 2" cavity. We would like to add a second story on top of the existing walls, so assuming the foundations are suitable (and we understand they are, but will require a dig to confirm), what are Building Regs in regard to the current requirements for cavity insulation and could I build with a 2" cavity and fill with a high u value insulation such as Kingspan or Celotex? Any advice / help appreciated.
Second Story Extension
- Thread starter c145hoo
- Start date
No you'll need additional insulation internally no matter what you stick in the cavity. It's theoretically possible to corbel the masonry skin out internally to create a wider cavity, or you could probably build it with a timber frame on the inside. Is this one of these making it up as you go along or are you employing someone to draw up some decent working/building regs drawings?
As per Freddie - you will have the additional pain of adding insulation to the walls either internally or externally, unless you can fathom a way of building with (at least) 105mm cavities.
I'll discuss the possibilities of 'corbel the internal masonry or have a timber interior frame' with our architect. His original idea was to install steels under the floor to support the internal wall for the second floor. Thanks for your help and advice.
Which is pretty standard