A daylight, sunlight, and overshadowing assessment was carried out for the surrounding properties close to the proposed new extension at Edgware, London. This report outlines the results of the assessment in order to assist with the developments planning application.

Edgware, London - Daylight Assessment - 3The methodology used for this assessment follows the most recognised guidance document for daylight and sunlight within dwellings and is titled ‘Site Layout Planning for Daylight and Sunlight – A Guide to Good Practice’ Second Edition 2011; by Paul Littlefair and is published by the Building Research Establishment.

Our report investigated the changes in natural light received between the existing and proposed plans. The following daylight, sunlight, and overshadowing assessments were carried out with the use of computer modelling software in order to provide the most accurate results possible.

  • Vertical Sky Component (VSC)
  • Annual Probable Sunlight Hours Received
  • Overshadowing Assessment

Edgware, London - Daylight Assessment - 1

The VSC results showed that all of the windows within the neighbouring property that face the proposed extension, will have a VSC value of greater than 27% under the proposed scheme. Therefore each window will be considered to receive an adequate amount of natural daylight and the impact of the proposed extension was therefore negligible.

The BRE guide states that a sunlight assessment is only required for living room windows. Without knowing the type of room behind each window a sunlight assessment was carried out for any window within 90° of due south. This was all of the windows at the neighbouring property that faced the proposed extension. The sunlight assessment results showed that all of the windows would receive an adequate amount of sunlight hours, for both the whole year and during the winter months only. The impact of the proposed extension was therefore be considered as negligible.

The overshadowing results showed that under the proposed scheme over half of the garden and terrace areas at the neighbouring property would still receive at least two hours of sunlight on 21st March, therefore the impact was considered as negligible.

Edgware, London - Daylight Assessment - 2In summary this assessment has shown that the impact to daylight, sunlight, and overshadowing of the neighbouring property caused by the proposed extension would be considered as negligible. Therefore the proposed extension was considered as acceptable in terms of daylight.