Windows and Doors in Historic Buildings
This page provides advice on improving the thermal performance of both windows and doors, which can be upgraded relatively easily without detracting from their appearance.
Draught-proofing windows and doors
Older buildings are prone to lose heat through gaps, which develop as various building elements move and distort over a long period. This can often be the case with windows and doors so that draughts develop.
Draught-proofing is one of the most cost-effective and least intrusive ways of improving the comfort of occupants and reducing energy use with little or no change to a building’s appearance.
Make sure you repair windows and doors before embarking on any draught–proofing measures.
Secondary glazing for windows
Secondary glazing is a fully independent window system, installed on the room side of existing windows. The original windows remain in position in their unaltered form.
Research has shown that heat loss can be reduced by over 60% by using secondary glazing with a low emissivity hard coating facing the outside.
Older buildings often have dormer windows which come in a variety of shapes, sizes and materials. If the main roof is being insulated then we would advise you to insulate any dormer window which is a part of that roof.
How to make sash windows energy efficient
The video below shows the practical steps that you can take to make your sash windows more energy efficient, from having them repaired to installing secondary glazing.
Related research on windows
Please read our report on Improving the Thermal Performance of Traditional Windows: Metal-framed Windows.