I have a couple of problem windows (both the same). They a made from softwood and are 600mm wide and 2000mm high. I suspect the joiner might of highlight the potential problem I had to my builder.

The windows have friction hinges and espag lock, which keep the opening side in check. The hinge side has warped so much that there is now a few mm gap in the seal (been gaffer taped over the winter.)

Any suggestion what I can put in the hinge side to for the windows straight. I remember looking at uPVC windows once that had some form of locating lug and bracket, that I think would do what I want, but I cannot find anything with google.

They are Double glazed if that makes a difference. They did start of straight, so I guess the glass is already stressed a little. i suspect pulling the frame back into shape will just unstress the glass slightly. I guess my problem with the hinge bolt is that there is no adjustment, and I may not close if I get it in the right position to pull the window fully back. (would have to put the bolt bit on the frame).