Lining windows and Doors with Timber frame to improve thermal performance

[ricardo100671]

We are doing a complete home refurb, including new door and window opening and I had an idea about lining these with a 2x4" treated timber frame into which windows and door can then be fitted. The benefits, I thought, would be

1. Precise opening dimensions avoids discrepancies during construction and window and doors can be confidently ordered when the build starts to avoid delivery delays.

2. Since wood has better thermal performance to brick, this will act as an thermal break between the window frames and brick work.

 

Any thought on why this may be a bad idea please.

 

Thank you 

 

[Redbeard]

Can you draw that? Are thinking to install them 'in check', where the win frame is tucked partly behind the outer skin of brickwork, so the timber lining in line with the inner skin? Is it solid walled?

[mike2016]

Wood has better thermal performance but it's not the best product for a thermal break. There are structural insulation boards that could be used (EPS) around the reveal but you would need some professional detailing to ensure correct installation and to prevent water ingress. You may find local companies - these are two in Ireland I'm aware of for comparison:

https://www.prodomo.ie/online-shop/#!/Structural-Insulation-Board/p/468917076/category=0

https://www.ecologicalbuildingsystems.com/product/phonotherm-200