MEC was commissioned by a private client to undertake a Daylight, Sunlight and Overshadowing Assessment in support of a proposed residential development at land to the rear of 8 St Julians Close, London. The scheme included three new dwellings alongside alterations to the existing property.
The site is surrounded by established 2–3 storey residential properties along St Julians Close, Lamberhurst Road, and Leigham Court Road, presenting a sensitive setting where daylight and sunlight impacts required detailed technical assessment.
MEC’s Lighting team delivered a comprehensive assessment in line with national guidance, including the BRE Site Layout Planning for Daylight and Sunlight: A Guide to Good Practice (2022) and BS EN 17037 Daylight in Buildings. A detailed 3D model was created using industry-standard software to simulate both existing and proposed conditions, enabling accurate analysis of surrounding windows and outdoor spaces.
The assessment considered the potential impacts on daylight, sunlight, and overshadowing, with a focus on ensuring habitable rooms and neighbouring gardens would continue to receive acceptable levels of natural light. In line with Paragraph 130 of the National Planning Policy Framework (2024), the study acknowledged the importance of making efficient use of land for housing delivery, while applying a flexible but robust approach to daylight and sunlight standards.
The main challenge lay in demonstrating that the development would not compromise the living conditions of nearby residents, given the site’s position within a closely built-up area. Careful analysis confirmed that all surrounding windows achieved the necessary daylight levels, while habitable rooms retained appropriate access to sunlight. Overshadowing tests showed that neighbouring gardens continued to receive at least two hours of sunlight on the spring equinox, meeting BRE expectations for outdoor amenity.
The planning decision issued in May 2025 did not raise any concerns relating to daylight, sunlight, or overshadowing. The Officer’s Report highlighted that MEC’s assessment demonstrated compliance with policy and confirmed the proposed development would not give rise to an unacceptable loss of light or adverse effects on neighbouring properties.
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