We have discovered that some of our 2G windows are draughty. The draught is coming in at the corner of the openable frames. Quite disappointed given these windows were very expensive and marketed as highly energy efficient.

 

 I’m going to raise this with the suppliers (who also did the install), but I’m just wondering how easy it is to fix this without using those unsightly aftermarket products. Windows were installed about 18 months ago, and I suspect the problem has been there from the beginning.

can you slide a piece of paper between the frame and the opener? 

get a straight edge, like a spirit level or a piece of mdf and see if the frame and openers are straight or if they have bowed.

So just to update: the windows company came back and tightened “the mushrooms” which are apparently what holds the window latches when the handle is closed. This has fixed the issue with the draught by the sofa. It turned out that was the only window affected. The other one was actually ventilation coming from the MVHR!