Daylight requirements in North Somerset are a recurring point of discussion for householders and developers across Weston-super-Mare, Clevedon, Portishead and Nailsea. Whether you are squeezing a rear extension onto a tightly packed seafront terrace or bringing forward a flatted scheme on a town-centre plot, the council expects you to demonstrate that your proposal will not unacceptably harm the daylight, sunlight and general living conditions of neighbouring properties. This article sets out how North Somerset Council deals with daylight and sunlight, which adopted policies apply, and where the recognised national standards fit in.
How North Somerset Council assesses daylight and sunlight
North Somerset is a unitary authority, so it acts as the local planning authority for its whole area (it does not include the city of Bristol or Bath, which have their own authorities). The two national parks do not extend into North Somerset, so the council determines applications under its own development plan throughout the district.
The starting point is the adopted development plan, which currently comprises the North Somerset Core Strategy (remaining remitted policies adopted January 2017) and the North Somerset Sites and Policies Plan Part 1: Development Management Policies (adopted July 2016), alongside the Sites and Policies Plan Part 2 and saved Replacement Local Plan policies. Together these set the framework against which the impact of a development on neighbouring amenity is judged.
The adopted Local Plan policies that matter
Two Development Management policies do most of the work on daylight and sunlight:
- Policy DM32 (High quality design and place-making) requires that “the design and layout should not prejudice the living conditions for the occupiers of the proposal or that of adjoining occupiers through loss of privacy, overlooking, overshadowing or overbearing impact.†Overshadowing and overbearing impact are exactly the issues a daylight and sunlight assessment addresses.
- Policy DM38 (Extensions to dwellings) permits extensions and ancillary outbuildings provided they “would not prejudice the living conditions of occupiers of adjoining properties†and retain adequate private amenity space. This is the policy most often engaged for the rear and side extensions common across North Somerset's residential streets.
Both DM32 and DM38 link back to Core Strategy Policy CS12 (Achieving High Quality Design and Place-Making), which underpins the council's design expectations.
North Somerset's daylight guidance position: the Residential Design Guide
Unlike many councils, North Somerset has adopted specific supplementary guidance on this point. The Residential Design Guide Supplementary Planning Document – Section 1: Living conditions of neighbours (adopted January 2013) sets out how the council assesses loss of light and overbearing impact. It expressly states that, to assess whether there will be an overbearing impact or significant loss of light to a habitable room, the council has regard to the Building Research Establishment guide Site Layout Planning for Daylight and Sunlight: A guide to good practice.
The SPD then applies a practical, two-stage 45-degree test to extensions: the first stage considers the depth and width of the extension, and the second considers its height. The test is taken from the centre of the nearest neighbouring ground-floor habitable-room window. As the guidance explains, if a proposed structure breaks the 45-degree line in both stages of the test, the proposal would normally be considered an unacceptable loss of light and overbearing impact and would be refused. The guide is clear that a “right to light†is a separate legal matter from planning, and that passing the test does not extinguish any private right.
In practical terms, this gives North Somerset applicants two layers to satisfy: the council's own 45-degree screening test for everyday extensions, and the more detailed BRE numerical analysis (vertical sky component, daylight distribution and the annual probable sunlight hours tests) where a scheme is larger, more sensitive, or where the 45-degree test alone does not resolve the question.
Is a daylight and sunlight report required to validate an application?
North Somerset's local validation list does not impose a blanket requirement for a standalone daylight and sunlight assessment on every application. However, amenity – including the effect on a neighbour's daylight and sunlight – is a material consideration the council must weigh in every relevant case. For new dwellings near existing homes, multi-storey and flatted schemes, backland and infill plots, and larger extensions, a properly prepared report is the most effective way to demonstrate compliance with DM32 and DM38 and to head off objections.
How the national standards fit in
Because the council's design guidance points directly to the BRE methodology, the recognised national framework is firmly in play in North Somerset. In practice this means:
- BRE BR 209 (2022 edition), Site Layout Planning for Daylight and Sunlight – the technical benchmark the council's SPD relies on for assessing loss of light to neighbours and adequate daylight within new homes;
- BS EN 17037 (Daylight in buildings) – the European standard for daylight provision within new dwellings, referenced in the current BRE guidance; and
- The National Planning Policy Framework (NPPF) – which expects new development to secure a good standard of amenity for existing and future occupiers, and which is implemented locally through the Core Strategy and Development Management policies.
Looking ahead, North Somerset is preparing a new North Somerset Local Plan (the emerging Local Plan running to the late 2030s/2040), which has progressed through pre-submission (Regulation 19) stages. Until that plan is adopted, the Core Strategy, the Sites and Policies Plan and the adopted Residential Design Guide remain the documents your scheme will be judged against.
What this means for your scheme
A few practical points for North Somerset applicants:
- Run the 45-degree test early. For extensions, the council's own test is the first hurdle. Designing to pass it from the outset avoids costly redesign.
- Commission a BRE-based report where the stakes are higher. For new dwellings, flats, and schemes close to neighbours, a vertical sky component and APSH analysis to BR 209 (2022) gives the case officer the objective evidence DM32 expects.
- Don't forget your own occupiers. The policies protect the living conditions of future occupiers of the proposal too, so internal daylight to new habitable rooms matters as much as the impact on neighbours.
How Fortress Associates can help
Fortress Associates prepares our daylight and sunlight report service to BRE BR 209 (2022), BS EN 17037 and the relevant Local Plan, including the North Somerset Core Strategy, the Sites and Policies Plan and the Residential Design Guide. We work nationwide with a 4–5 working day turnaround and no advance payment. We also produce Building Regulations drawings to the Approved Documents (Parts A–S). To discuss a North Somerset site, get in touch with our team. If you are working in the neighbouring new unitary further north, see our companion guide on daylight requirements in North Yorkshire.
Sources & further reading
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