BRE Daylight and Sunlight Tests

Tests to assess the impact, if any, a new development will have on the light to neighbouring properties
are provided in :

'BRE Digest 209: Site Layout Planning for Daylight and Sunlight'

The BRE tests are approved by the Department of the Environment and are widely used by local
authorities when deciding on development applications. It is becoming increasingly common for planning
bodies to insist on a daylight and sunlight survey prior to granting planning permission.

The BRE guidance provides three main tests which should be applied to assess the impact on light to
neighbouring properties as a result of new development:

1. Diffuse daylighting to windows
2. Sunlight availability to windows
3. Sunlight availability to open spaces and gardens