13. Daylight, Sunlight and Overshadowing Assessment
What is it?
Policy DES1 of the Plan Strategy requires that proposals ensure no undue effect on the amenity of neighbouring properties or public spaces by minimising the impact of overshadowing and loss of daylight.
Policy RD1 requires that proposals do not unduly affect the amenity of neighbouring residents, including loss of light and overshadowing.
A Daylight, Sunlight and Overshadowing Assessment assesses the impact of the proposal on existing surrounding properties and open spaces in terms of daylight and sunlight. It may also assess the performance of the development for future occupants.
When is it required?
A Daylight, Sunlight and Overshadowing Assessment should be provided with all applications involving:
- buildings exceeding four storeys in height where adjoining other developed land or public open spaces; or
- where proposed buildings or extensions could lead to harmful overshadowing of adjacent or other proposed buildings or spaces within or outside the site; or
- where the proposed development would itself be subject to significant shading from adjoining buildings or trees, or the proposed development itself.
What should it include?
A Daylight, Sunlight and Overshadowing Assessment should include:
- an aerial plan that shows shadowing impacts on adjacent buildings and public open spaces within and outside the site in respect of both the existing situation and proposed situation following implementation of the proposal. The assessment should be provided at the Spring Equinox (20 March or 21 March) and during the following times of day - 8am, 10am, 12pm, 2pm, 4pm, and 6pm.
For applications for Major development, the assessment should include an assessment consistent with the latest relevant Building Research Establishment (BRE) guidance.
- an assessment of daylight and sunlight levels within the proposed development itself.
For applications for Major development, the assessment should include an assessment consistent with the latest relevant Building Research Establishment (BRE) guidance.
