DIY Doctor

UPVC Windows in an extension and position over cavity

Postby Rossitm » Tue Nov 10, 2020 8:11 am

Morning all. I’m after some advice on fitting windows in my extension. I read somewhere that the windows need to be 30mm over the cavity? Is this correct? I’ve changed all the other windows in my house and fixed to the inside of the outer brick. Does this mean these are incorrect? Thanks in advance
Rank: Labourer
Progress to next rank:
Posts: 1
Joined: Tue Nov 10, 2020 7:58 am


Simply Build It

Postby stoneyboy » Thu Nov 12, 2020 10:39 pm

Hi rossitm
The installation of replacement windows with the inner face flush with the inside face of the outer brickwork is not wrong. Ideally the windows should be installed to avoid cold bridging but in many cases it is a compromise because replacement windows are shallower than the original. Fitting a upvc strip around the inside of the window overcomes this issue.
Regards S
Rank: Project Manager
Posts: 4387
Joined: Wed Dec 10, 2008 6:44 pm

Display posts from previous
Sort by
Order by

  • DIY How to Project Guides
  • DIY how to tutorial projects and guides - Did you know we have a DIY Projects section? Well, if no, then we certainly do! Within this area of our site have literally hundreds of how-to guides and tutorials that cover a huge range of home improvement tasks. Each page also comes with pictures and a video to make completing those jobs even easier!

  • Related Topics