Timber sash windows versus uPVC
We believe that traditional sash windows and casement windows are an essential feature of a period building’s character, it’s vital to retain them both for aesthetic reasons, and for the value they add to your property.

Renovating your timber windows and doors has clear environmental benefits over installing new uPVC windows – so it’s not only good for your home, but good for the environment too.
The problems with uPVC windows versus timber sash windows
Renovating your existing wooden doors or windows is a far more sustainable alternative to uPVC. It uses around 40 times less energy by using existing materials rather than extracting new ones, and there’s also a big reduction in landfill, since waste wood and glass can easily be recycled or reused.
- 82% of uPVC goes to landfill
- 43% of uPVC is made up of non-renewable resources
- 15% of uPVC is incinerated
- Only 3% of uPVC is recycled
Life expectancy
A window frame’s life expectancy depends on many factors, so it can be hard to provide exact figures. However, the National Building Federation estimates that uPVC window frames will last around 20 to 25 years, whilst vacuum-treated softwood frames have a life expectancy of around 25 to 35 years. And according to the Green Building Digest, “well designed and well maintained timber windows can and do last the lifetime of the building in which they are installed.”
For more information you can read WWF’s Report: Window of Opportunity.