Two separate things are usually under warranty
uPVC window and door warranties typically cover two different things, sometimes on different terms — worth understanding before you assume "the warranty" means one single blanket promise.
The profile (frame) warranty
This covers the uPVC frame itself — discoloration, structural integrity, the material not degrading under normal use. Profile manufacturers (the companies that make the raw uPVC sections fabricators build with) often provide their own warranty separate from whoever installed your windows, since the material itself is manufactured upstream.
The installation warranty
This covers the fabricator's own workmanship — whether the frame was fitted correctly, sealed properly, and functions as it should. A perfectly good profile installed poorly can still leak or fail at the frame junction, which is why this is usually a separate promise from the fabricator, not the profile manufacturer.
What to actually ask before you commit
- Is the profile warranty from the fabricator or the profile manufacturer directly, and for how long?
- Is installation workmanship covered separately, and for how long?
- What voids the warranty — DIY repairs, third-party servicing, anything specific?
- Is the warranty transferable if you sell the property?
Get it in writing
A verbal assurance is easy to make and hard to rely on later. Ask for the actual warranty terms in writing before finalizing anything — a legitimate fabricator should have no issue providing this.