Blocking up a large window

[Jamie2106]

Hi all

Our house is a converted shop, and the former shop windows have been blocked up and replaced with a much smaller window and a door.

I've just found that the previous owners did this by building a timber frame, plasterboarding the inside and adding a skin of 8mm ply on the outside, which has then been rendered over.

This is clearly a bodge, but I'm wondering whether it would be OK to just replace the outer skin with thicker ply, or some other suitable material, or whether to bite the bullet and have the whole lot rebuilt in brick.

The two former windows are 3.7 and 5.7 m wide respectively and full height, 2.4m.

 

[stevethejoiner]

Its another one where you will really only know how far to go when you start. If it is a bodge, you will probably find the studding may have rotted now, and your have to replace it all. There is nothing wrong with a stud wall and ply to outside, its done on new build to this day. but now we usually have a breathable membrane to the outside, with a full fill of good instillation in the stud cavity.
A 4" or 100 stud wall, full cavity filled, ply external, membrane, mesh, and render is fine, and you do not lose space inside the room. If you go with brickwork you will need a cavity wall and that takes up room.