Updated June 2026 · CW Doors & Windows
When should windows be replaced? Signs to look for
Windows don't fail overnight — they degrade slowly. Here are the 7 signs that mean replacement is the right call, and the ones where a £150 repair is all you need.
7 signs you need new windows
1) Misted or condensation between the panes — sealed unit has failed.
2) Visible rotting (timber) or cracked/discoloured frames (uPVC over 25 years old).
3) Persistent draughts even after gasket replacement and hinge adjustment.
4) Single glazing or pre-2005 double glazing — energy losses are significant.
5) Windows won't open, close, or lock properly even after servicing.
6) Visible water ingress around the frame or onto the windowsill.
7) Selling the property and the windows are dated — buyers walk away.
Repair, don't replace, if:
Only one window is misted and the rest are fine — replace just that sealed unit.
Hinges have dropped — adjustment is usually free from the original installer.
Gaskets have hardened — replacement gasket is £20–£40 per window.
Cylinder is worn or you've lost a key — replace just the cylinder, £40–£80.
Typical replacement cost in Leicester
Whole 3-bed semi: £4,500–£8,000. Larger detached: £8,000–£14,000. Single window: from £450.
Repair, reglaze or replace
A single misted pane can often be solved with a new sealed unit. A handle or hinge that sticks may just need adjusting. Replacement makes sense when the frame itself is failing, the locks no longer secure, or several units have misted at once.
We give that advice on a free measured survey within 5 days. If replacement is right, windows start from £450 fully fitted by our own fitters, with a 10-year insurance-backed guarantee.
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