Windows provide an outlook on the world. They help set the tone and character for a building and the area in which it stands. Windows define natural lighting levels and thermal comfort essential for the wellbeing of residents. They offer sound protection and keep homes safe from intrusion. Windows are an essential part of the building fabric and as such contribute to a development’s overall energy performance.

Modern factory-finished timber windows have a better environmental performance than any other window material. They have a longer service life and lower whole life costs than uPVC windows. Wooden windows can be repaired and recoated throughout their lifetime and are the best option for achieving zero carbon buildings. They can be sourced from local manufacturers using home-grown timber and support economic recovery in Wales.

The multiple benefits wooden windows deliver over their life-span in terms of maintenance, durability, embodied carbon, and other social and environmental aspects make them excellent value for money.

This document provides information for specifiers and procurement specialists working on social housing projects. It is designed to help with the specification of low-carbon timber windows in a social housing context. It provides performance criteria and indicates what needs to be considered to achieve these in practice. Windows are an essential element of the building fabric and should not be discussed in isolation. They should be considered very early in the design process when deciding what build system to use.