Are new windows worth it? An honest installer's answer

Misted units. Once the seal has failed there is no repair — only replacement. Misted units lose almost all of their insulating value.

Single glazing. Replacing single glazing with A-rated double glazing typically cuts heat loss through the window by 60–70%.

Rotting timber or failing uPVC frames. If the frame won't hold the new unit, the unit fails again within months.

Pre-2005 double glazing. The A-rating standard came in 2010; anything older is leaking significant heat compared to modern units.

Your glazing is under 10 years old, the seals are intact, and you just don't like the colour. A respray is cheaper.

A single window has failed but the others are fine. Replace just that one.

You're moving in 12 months. The payback won't land before you sell — though new windows do improve sale price.

A typical 3-bedroom Leicester semi replacing first-generation double glazing with modern A-rated units saves around £180–£250 per year on energy bills (Energy Saving Trust figures, adjusted to current prices). Payback on a £6,000–£8,000 whole-house job is 25–35 years on energy alone.

If you're replacing single glazing the saving is much larger — typically £350–£450 per year, with payback around 15 years.

The financial case usually breaks even faster when you factor in the increase in home value (typically 3–5% in our area) and reduced noise.

Noise. Modern acoustic glazing units cut external noise by 30–40 dB — the difference between a busy road being intrusive and being barely noticeable.

Security. Modern multi-point locking and laminated glass options are dramatically better than pre-2005 windows.

Condensation. Modern warm-edge spacer bars dramatically reduce internal condensation.

Maintenance. Modern uPVC and composite units need a wipe twice a year and nothing else for 20 years.