Daylight and Sunlight

The BRE (Building Research Establishment) gives recommendations for daylight levels both within proposed new buildings and for surrounding properties. These are set out in the BRE report 'Site layout planning for daylight and sunlight - A guide to good practice', 1991 by P J Littlefair. Many local authorities have adopted this guide, so that the criteria set out therein can form the basis for granting or refusing planning permission.

What can we do?

We can advise developers, architects, surveyors and local authorities on the extent to which their proposed development meets the BRE guidelines. In cases where the development blocks light to key windows, we can advise exactly how far a scheme would have to be reduced in order to meet the guidelines. We can also advise surrounding property owners on the extent of any breach of the guidelines, providing a strong case for the reduction of any such development.

There are several features we look at in assessing the effect of a development on surrounding properties. These are:

Vertical Sky Component (VSC)
Sunlight Availability
Permanent Shadow
Shadow Animations

There are also ways of estimating interior daylight levels within a proposed development which are:

Average Daylight Factors (ADF)
Real illumination levels


back introduction