A daylight, sunlight, and overshadowing assessment was carried out for the surrounding properties close to the proposed new extension at Meadfield, Edgware. The report outlined the results of the assessment in order to assist with the developments planning application.
The methodology used for the assessment followed the most recognised guidance document for daylight and sunlight within dwellings, 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.
The 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
The VSC results showed that all of the windows to the rear of the 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 is 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 to the rear of the property. The sunlight assessment results show 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 would therefore be considered as negligible.
The overshadowing results show that under the proposed scheme over half of the garden area would still receive at least two hours of sunlight on 21st March, therefore the impact would be considered as negligible.
In summary the assessment showed that the impact to daylight, sunlight, and overshadowing of the surrounding properties caused by the proposed extension would be considered as negligible. Therefore the proposed extension was considered as acceptable.