What are the options to close a 200mm cavity?

[CalvinHobbes]

 

Getting a price for lintels and he just asked me would we want deep or thin sills and how are we closing the cavity? (he said something about core bridge?? and 4x3 and 6 x 4 and plasterboard was useless to screw up.

 

[Dave Jones]

https://subframes.co.uk/cavity-closers/kingspan/

 

[Canski]

are you on the new regs ? I think I read something in there that the window has to overlap the outside of the inner skin by 30 mm. This would lead to a cill the size of a window board

[Dave Jones]

nearly, you want the window 30mm onto the outer brick/block, just enough to weather seal it with the majority of the frame sitting in the insulation envelope.