Understanding the daylight requirements in North Warwickshire Borough Council is important for anyone proposing a house extension, an infill dwelling or a larger residential scheme across this borough, from the market town of Atherstone on Watling Street to Coleshill, Polesworth and the villages set between the M42, M6 and the route of HS2. North Warwickshire Borough Council is the local planning authority (LPA) for the area; Warwickshire County Council is the upper-tier authority but does not determine most householder and residential applications. This guide explains how daylight and sunlight are considered locally, which adopted policies apply, and what an assessment to recognised standards involves.
Daylight requirements in North Warwickshire: the policy framework
The development plan for the area is the North Warwickshire Local Plan 2011-2033, which was adopted in September 2021. It sets out both the strategy for growth and the detailed development management policies that officers apply when assessing the impact of a proposal on neighbouring living conditions.
The borough is shaped by its geography. Much of it lies within the Green Belt that wraps around the West Midlands conurbation, which directs most new housing to the existing towns and larger villages where plots can be constrained. At the same time, North Warwickshire has seen significant pressure from HS2 construction and large-scale logistics and distribution development, given its position on the strategic motorway and rail network. Both factors make the careful protection of residential amenity in the established built-up areas all the more important.
Policy LP29 and Policy LP30
The principal amenity policy is Policy LP29: Development Considerations. This sets out a list of criteria that all development is expected to meet, and criterion 9 is the one most relevant to daylight and sunlight: it requires development to avoid an unacceptable impact through overlooking, overshadowing and loss of light to neighbouring occupiers. In other words, the policy treats loss of daylight and sunlight, overshadowing and loss of privacy as distinct but related tests that a scheme must satisfy.
Sitting alongside it, Policy LP30: Built Form addresses the design, scale, massing and layout of development, expecting proposals to respond to the character of their surroundings. Scale and massing are directly connected to daylight outcomes: a tall or deep building close to a boundary is far more likely to overshadow a neighbour or feel overbearing than a modest, well-set-back one, so Policies LP29 and LP30 are usually read together.
The 45-degree rule in the householder design guide
North Warwickshire supports these policies with a Supplementary Planning Document, "A Guide for the Design of Householder Developments" (September 2003). Although it predates the current Local Plan, it remains the council's practical design reference for extensions and alterations, and it sets out the well-established 45-degree rule for assessing loss of light.
The 45-degree test is a simple geometric check. Working from the centre of a neighbour's nearest habitable-room window, a line is drawn at 45 degrees on plan (and often in elevation as well) towards the proposed development. If the new building or extension crosses that line, it is taken as an indication that an unacceptable loss of daylight may occur, prompting closer scrutiny. It is a quick screening tool rather than a precise measurement of skylight, which is why a more detailed technical assessment is often needed where a proposal is borderline or where the 45-degree line is breached.
Which technical standard applies
Where the 45-degree screening test suggests a realistic prospect of harm, the recognised national methodology comes into play. 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. The National Planning Policy Framework (NPPF) supports making efficient use of land while securing well-designed places and a good standard of amenity, and these national documents are applied through the adopted policies and the householder guide above. BR 209 provides the numerical tests that allow the qualitative language of criterion 9 of Policy LP29 to be measured objectively.
What a daylight and sunlight assessment involves
A BRE-based assessment typically 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 (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 months;
- Overshadowing of gardens and amenity areas - using the sun-on-ground test on the equinox.
A clear, BRE-compliant report helps a North Warwickshire planning officer move beyond the 45-degree screening line and judge a proposal properly against criterion 9 of Policy LP29 and the built-form expectations of Policy LP30. It is particularly valuable for two-storey rear and side extensions in Atherstone and Coleshill, infill plots within the towns, and any scheme where the 45-degree line is breached and a more rigorous answer is needed. A robust assessment cannot promise consent, but it gives officers the evidence to reach a sound decision and helps applicants design out 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 Atherstone, Coleshill, Polesworth and the wider North Warwickshire borough. We work 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. For a comparable authority, see our guide to daylight requirements in Tandridge.
Sources & further reading
- North Warwickshire Borough Council - Planning policy (Local Plan 2011-2033 and householder design guide)
- BRE - BR 209: Site Layout Planning for Daylight and Sunlight (2022)
- GOV.UK - National Planning Policy Framework
- Fortress Associates daylight and sunlight reports
- Our services and our guide to getting 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