Whether you are extending a home in Kilmarnock, building in Cumnock or bringing forward a larger residential scheme, it pays to understand the daylight requirements in East Ayrshire before you apply. East Ayrshire Council is the planning authority, and it judges the impact of development on daylight, sunlight, overshadowing and privacy through its adopted Local Development Plan together with national policy. This article sets out the relevant policies, the local design tests, and how a professional daylight and sunlight report can support your application.
The planning framework in East Ayrshire
In Scotland the statutory development plan has two parts that are read together: the council's adopted Local Development Plan (LDP) and the National Planning Framework 4 (NPF4), adopted by Scottish Ministers on 13 February 2023. Applications across East Ayrshire are determined against both.
The current local plan is the East Ayrshire Local Development Plan 2 (LDP2), which the council adopted on 23 July 2024. LDP2 replaced the previous 2017 Local Development Plan and now sets the planning strategy for the council area, including Kilmarnock, Cumnock, Stewarton, Galston and the surrounding settlements. Because LDP2 post-dates NPF4, the two are closely aligned, but where any conflict arises NPF4 prevails as national policy.
Which East Ayrshire policies deal with daylight and sunlight?
In East Ayrshire, daylight and sunlight are treated as part of design and residential amenity. The most relevant adopted policy is:
- Policy DES1: Development Design – the council's main design policy, which requires development to be well designed and not to significantly reduce the amenity of neighbouring properties through overshadowing, overlooking or an overbearing impact.
Policy DES1 is supported by the council's adopted Design Supplementary Guidance, including Appendix 2: Householder Development. This guidance is unusually specific for a Scottish authority and sets out two clear, locally applied tests:
- The 45-degree daylight test. The guidance states that single-storey extensions “should be designed so as not to cross a 45° line from the midpoint of the nearest window of the adjoining house. The shadow created by the proposed extension should not overshadow more than 50% of the adjoining window in both elevation and plan.”
- A privacy separation distance. As a general rule, new windows should be over 18 metres from facing windows of habitable rooms to protect privacy and avoid overlooking.
This local design guidance establishes the amenity principle and a useful first-pass test. For more detailed or contested cases, the recognised best-practice technical method is used to demonstrate compliance.
How daylight and sunlight are actually measured
The UK best-practice method is the Building Research Establishment guide BRE BR 209, Site Layout Planning for Daylight and Sunlight: A Guide to Good Practice (third edition, 2022), used together with the British and European Standard BS EN 17037. The council's 45-degree rule is a helpful screening test, but a full BR 209 assessment provides the detailed numerical analysis that planners and neighbours often rely on, and it supports the amenity and design aims of Policy DES1 and NPF4.
A typical report assesses:
- Vertical Sky Component (VSC) – the skylight reaching a neighbour's window, with a BR 209 guideline of 27% and a noticeable reduction generally where the retained value falls below 0.8 times the previous level.
- No Sky Line / Daylight Distribution – how much of a room still receives direct skylight after development.
- Annual Probable Sunlight Hours (APSH) – sunlight to windows facing within 90 degrees of due south, over the year and in winter.
- Overshadowing of gardens and amenity space – whether at least half of a garden or sitting-out area receives sunlight at the equinox.
For new dwellings, BS EN 17037 also informs the daylight provided within the homes, supporting the quality-of-life aims that run through LDP2 and NPF4.
NPF4 policies to be aware of
NPF4 carries significant weight in every decision. The most relevant policies for daylight and sunlight are Policy 14 (Design, quality and place), which seeks well-designed places that protect amenity, and Policy 16 (Quality homes), which promotes high-quality, well-designed housing. A BRE-based report is an effective way of showing East Ayrshire Council that a scheme respects both Policy DES1 and these national objectives.
When you are likely to need a daylight and sunlight report
An assessment is commonly needed or advisable where:
- a two-storey extension, dormer or rear addition could overshadow a neighbour's windows or garden, or fails the council's 45-degree test;
- a new house or flatted development sits close to existing homes in Kilmarnock, Cumnock or another town;
- an infill or backland plot is proposed in an established residential street; or
- a case officer or neighbour has raised loss of light, overshadowing or overlooking as a concern.
A clear, BR 209-compliant report submitted early can address objections directly and give the planning officer the evidence needed to apply Policy DES1 with confidence.
How Fortress Associates can help
Fortress Associates provides our daylight and sunlight report service to homeowners, architects and developers in East Ayrshire and across the UK. Every report is prepared to BRE BR 209 (2022) and BS EN 17037 and written to support the design and amenity policies of East Ayrshire LDP2 and NPF4. We work to a 4–5 working day turnaround with no advance payment. See our services or contact us to discuss your project.
Sources & further reading
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