On 21/01/2021 14:58, Davidm wrote:
I've got a couple if uPVC double glazed windows which have become very
drafty around the opening casements. It seems at the the "nylon
looking" seal in the frame, which the casement frame closed onto, has
lost it's elasticity and is not sealing the gap. The windows are about
30 years old, BAC I think. Is it possibe to replace these seals, and
are replacements available? Anyone done this and know if it's easy or
don't even try? Any other solution (apart from replace the whole
window)?

Ebay and Amazon sell replacement seals. Depending upon type, even
Screwfix do. They are usually just pull out and push in.