Hi all, hope you're well.
We're getting "near" the end of the renovation on our 1930's semi-detached home with 9" solid brick walls.
....Well, I keep telling myself and my wife the "end is near"
, and both have an issue and need need some help/advice regarding our main front room Window.
The window in question is pretty wide at 3 metres and relatively new (was installed ~3yrs ago).
The issue:
Since install it's felt very draughty (compared to all the other windows in the house from the same installer + manufacturer).
The installer re-sealed the outside left & right sides (~7-10mm) when we first let them know of the issue, with a pretty standard looking frame sealant in a gun (from memory) and then said due to the "window rubber seals being gap/draught free, that It'll be an issue with your brickwork" if the issue isn't fixed??? It never was...
I've since inspected the brickwork (not really knowing what to look for other than obvious gaps in the pointing etc) and can't see much other than the smallest of gaps in a small area of sealant used below outside window sill/ledge.
So am firstly wondering what to look out for in such buildings to fix the issue and how best to do it (a DIY solution would be ideal, but happy to hire a pro if required/best practise).
Advise:
On the inside of the same window, we've had the entire wall around the window stripped back to brick and lime plastered (see attached picture).
So am wondering how best to fix a (solid) Oak window board down? I assume slathering a load of "modern" grab adhesive (+ screwing it down) will counteract the breathability of the lime plaster? So am ideally looking for a breathable fixing solution with some kind of draught proofing if possible - if I never find the cause of the draught - is laying a very thin 1-2mm wool/felt-like material on top of the plaster/under the board and screwing down an option???
Many thanks all. Any help is hugely appreciated.

We're getting "near" the end of the renovation on our 1930's semi-detached home with 9" solid brick walls.
....Well, I keep telling myself and my wife the "end is near"
The window in question is pretty wide at 3 metres and relatively new (was installed ~3yrs ago).
The issue:
Since install it's felt very draughty (compared to all the other windows in the house from the same installer + manufacturer).
The installer re-sealed the outside left & right sides (~7-10mm) when we first let them know of the issue, with a pretty standard looking frame sealant in a gun (from memory) and then said due to the "window rubber seals being gap/draught free, that It'll be an issue with your brickwork" if the issue isn't fixed??? It never was...
I've since inspected the brickwork (not really knowing what to look for other than obvious gaps in the pointing etc) and can't see much other than the smallest of gaps in a small area of sealant used below outside window sill/ledge.
So am firstly wondering what to look out for in such buildings to fix the issue and how best to do it (a DIY solution would be ideal, but happy to hire a pro if required/best practise).
Advise:
On the inside of the same window, we've had the entire wall around the window stripped back to brick and lime plastered (see attached picture).
So am wondering how best to fix a (solid) Oak window board down? I assume slathering a load of "modern" grab adhesive (+ screwing it down) will counteract the breathability of the lime plaster? So am ideally looking for a breathable fixing solution with some kind of draught proofing if possible - if I never find the cause of the draught - is laying a very thin 1-2mm wool/felt-like material on top of the plaster/under the board and screwing down an option???
Many thanks all. Any help is hugely appreciated.

