Description

Windows and doors are among the most important elements affecting a home's thermal performance.

This bulletin explains how to specify window and door systems that comply with the 6th editions of H1/AS1 and H1/VM1, covering construction R-values, glazing options, frame types, solar heat gain, installation and the factors that influence energy efficiency and occupant comfort.

Scope

This bulletin includes:

1. Introduction
2. Construction R-values for windows, doors and skylights
3. How window components impact on thermal performance and durability
   1. Framing material
   2. Thermally broken aluminium
   3. Spacers
   4. Low-E glass
   5. IGU gas fill
   6. Other considerations around thermal performance
   7. Drainage and durability
4. WEERS (Window Energy Efficiency Rating System)
5. Specifying windows
6. Installation considerations
7. More information