Understanding the daylight requirements in South Ribble Borough Council is important for anyone proposing a house extension, an infill dwelling or a larger residential scheme in this part of central Lancashire, from Leyland and Penwortham to the communities along the River Ribble that face Preston across the water. South Ribble Borough Council is the local planning authority (LPA) for the area; Lancashire County Council is the upper-tier authority but does not determine most householder and residential planning applications. This guide sets out how daylight and sunlight are considered locally, which adopted policies apply, and what a sound assessment to recognised national standards involves.
Daylight requirements in South Ribble Borough Council: the policy framework
The development plan for the borough is made up of two adopted documents. The South Ribble Local Plan was adopted on 22 July 2015 and contains the borough's detailed development management policies. It sits alongside the Central Lancashire Core Strategy, adopted in 2012 and shared with Preston and Chorley, which provides the strategic framework for the wider Central Lancashire area.
For daylight, sunlight and residential amenity, the key policies are:
- Local Plan Policy G17 - Design Criteria for New Development, which sets out the borough's expectations for good design and, importantly, addresses separation distances to protect neighbours from overlooking, overshadowing and overdominance; and
- Core Strategy Policy 17 - Design of New Buildings, the strategic design policy requiring development to be of high quality, to respect its context and to safeguard the amenity of existing and future occupiers.
Policy G17 is the policy most often engaged by householder and residential applications. Its concern with overlooking, overshadowing and overdominance maps directly onto the three issues that daylight and sunlight assessments are designed to test: privacy between facing windows, the amount of skylight and sunlight reaching neighbouring rooms and gardens, and the bulk and proximity of new building as experienced from neighbouring properties.
Separation distances and overshadowing
South Ribble's design criteria use separation distances as a practical first check on amenity. Maintaining an appropriate distance between facing habitable-room windows guards against overlooking, while the spacing between a new building and a neighbour's boundary and windows influences both overshadowing and the sense of enclosure or overdominance. Separation distances are a useful screening tool, but they are not a complete answer on their own; where levels change, where buildings are taller, or where the geometry is unusual, a more detailed daylight and sunlight assessment gives officers a reliable measure of the actual effect.
The emerging Central Lancashire Local Plan
South Ribble, Preston and Chorley have been preparing a joint Central Lancashire Local Plan to replace the current suite of documents with a single up-to-date plan for the three authorities. Until that emerging plan is adopted, the adopted 2015 Local Plan and the 2012 Core Strategy remain the starting point for decisions, and their design and amenity policies continue to apply. Applicants should always check the current status of the plan before submitting.
How BRE BR 209 applies
South Ribble does not publish a bespoke daylight and sunlight Supplementary Planning Document. Where a proposal needs to be tested for its effect on daylight and sunlight, the recognised national methodology applies. That methodology is the Building Research Establishment guidance, BRE BR 209: Site Layout Planning for Daylight and Sunlight - A Guide to Good Practice (2022 edition), read alongside the British Standard BS EN 17037 on daylight in buildings. These documents are applied through the borough's adopted amenity policies and within the framework of the National Planning Policy Framework (NPPF), which supports making efficient use of land while securing well-designed places and a good standard of amenity.
What a daylight and sunlight assessment involves
A BRE-based assessment usually considers two questions: the daylight and sunlight enjoyed by neighbouring properties, and the daylight and sunlight that future occupiers of the proposed development will receive. The principal tests include:
- Vertical Sky Component (VSC) - the amount of skylight reaching the centre of a neighbour's window, with a guideline value of 27%, or no worse than 0.8 times its former value;
- Daylight distribution (the no-sky line) - how daylight is spread across the depth of a room;
- Annual Probable Sunlight Hours (APSH) - the sunlight reaching windows with a significant southerly aspect, assessed across the whole year and the winter period;
- Overshadowing of gardens and amenity areas - using the sun-on-ground test on the equinox.
A clear, BRE-compliant report helps a South Ribble officer judge a proposal against Policy G17 and Core Strategy Policy 17. It is particularly valuable for two-storey rear and side extensions in the established streets of Leyland and Penwortham, infill plots between existing homes, and riverside and fringe sites near the Ribble where levels and orientation can affect the result. A robust assessment cannot promise consent, but it gives officers the evidence to reach a sound decision and helps applicants resolve potential problems before submission.
How Fortress Associates can help
Fortress Associates prepares our daylight and sunlight report service to BRE BR 209 (2022) and BS EN 17037 for projects across Leyland, Penwortham and the wider South Ribble borough. We work UK nationwide with a typical 4 to 5 working day turnaround and ask for no advance payment. You can see the full range on our services page or contact us to discuss your site. We also produce Building Regulations drawings where these are needed alongside a planning submission.
Sources & further reading
- South Ribble Borough Council - Planning Policy and the Local Plan
- BRE - BR 209: Site Layout Planning for Daylight and Sunlight (2022)
- GOV.UK - National Planning Policy Framework
- Fortress Associates daylight and sunlight reports
- See also our guide to daylight requirements in Oadby and Wigston, our services and how to get in touch
Need help with a UK planning project?
Fixed-fee daylight reports and Building Regulations drawings — delivered in 4–5 working days. No advance payment.
Request a free quote