Daylight Consultants in the UK
Browse 52 verified daylight consultants across the UK. Get quotes for Daylight and Sunlight Assessment, Overshadowing Analysis, Rights to Light Report and more.
52 verified daylight consultants across the UK on The Planning Review.
What does a daylight consultant do?
A daylight consultant assesses how a proposed development will affect the natural light received by neighbouring properties and whether the new dwellings themselves will have adequate daylight and sunlight. Their work follows the methodology set out in BRE Report BR 209 (Site Layout Planning for Daylight and Sunlight), which provides the numerical criteria used by LPAs across the UK to evaluate light impacts. In urban areas, particularly London and other major cities where development densities are high, a daylight and sunlight assessment is almost always required for planning applications involving new buildings of any significant scale.
The consultant uses specialist software to model the development in 3D and calculate key metrics. Vertical Sky Component (VSC) measures how much sky is visible from a neighbouring window. Annual Probable Sunlight Hours (APSH) measures expected hours of direct sunlight. Daylight distribution assesses how far daylight penetrates into a room. For amenity spaces, overshadowing analysis determines whether adequate sunlight reaches the ground. Where the development causes reductions beyond BRE thresholds, the consultant advises the design team on modifications (adjusting massing, setbacks, or window positions) to bring impacts within acceptable limits.
Daylight consultants also assess internal light levels within the proposed development, ensuring new homes receive sufficient natural light for occupant health and wellbeing. The London Plan Policy D6 requires adequate daylight provision in new housing, and BS EN 17037 provides a modern climate-based framework for daylight assessment that some LPAs are beginning to adopt alongside the BRE guidelines. Early engagement (ideally at RIBA Stage 2) allows daylight considerations to shape the design from the outset rather than forcing costly changes later.
When do you need a daylight consultant?
- The proposed development is taller or closer to neighbouring properties than the existing situation and could reduce their daylight or sunlight
- The LPA's validation checklist requires a Daylight and Sunlight Assessment for the planning application
- The development is in a dense urban area where close proximity to existing buildings makes daylight impact a likely concern
- Neighbours have objected or are expected to object on grounds of loss of light or overshadowing
- The proposed building is over 3 storeys and within 25 metres of existing residential windows
- The scheme is in London and must demonstrate compliance with London Plan Policy D6 on housing quality
- New amenity spaces (gardens, courtyards, playgrounds) must receive adequate sunlight under BRE criteria
- You want to optimise the design early to avoid daylight-related objections or reasons for refusal at committee
- An existing or proposed right to light may be affected and you need a preliminary assessment before instructing a surveyor
Services you can get local quotes for
- Daylight, Sunlight & Overshadowing
- Light Pollution Assessment
- Rights to Light
- Solar Glare Assessment
Frequently asked questions
How much does a daylight and sunlight assessment cost?
For a small residential development affecting a handful of neighbouring windows, a daylight and sunlight assessment typically costs between £3,000 and £6,000. For medium-scale urban schemes (apartment buildings affecting 20-50 neighbouring windows), fees of £6,000 to £15,000 are common. Large or complex developments in dense urban areas — particularly in central London, where hundreds of windows may be affected and multiple iterations of design advice are needed — can cost £15,000 to £40,000 or more. Internal daylight assessments for the proposed development itself are often included or charged as an additional £2,000 to £5,000.
How long does the process take?
A daylight and sunlight assessment for a straightforward scheme can be completed within 3 to 5 weeks, provided the architect's drawings and site survey data are available. Complex urban schemes requiring multiple design iterations typically take 6 to 10 weeks. Where the assessment reveals significant transgressions that require design changes, the process may take longer as the consultant and design team work through alternatives. Early engagement — ideally at RIBA Stage 2 — allows daylight considerations to be integrated into the design from the outset, avoiding costly redesign later.
What are VSC and APSH?
Vertical Sky Component (VSC) measures the amount of sky visible from the centre of a window face, expressed as a percentage. The BRE guideline target is 27% for an unobstructed window; if the proposed development reduces a neighbour's window to below 27% VSC and the reduction is more than 20% of its former value, the impact is considered noticeable. Annual Probable Sunlight Hours (APSH) measures the total hours of direct sunlight a window could receive over a year. The BRE guideline is 25 hours of total APSH, with at least 5 hours during the winter months (21 September to 21 March). Both are comparative metrics — the assessment compares the existing and proposed situations.
Are the BRE guidelines mandatory?
No. The BRE guidelines in BR 209 are advisory, not statutory. They describe a methodology and numerical benchmarks for assessing daylight and sunlight impacts, but they are not building regulations or planning policy. LPAs use the guidelines as a framework for decision-making, but they apply professional judgment to the results. In dense urban areas, LPAs routinely accept some degree of transgression of BRE targets where the overall planning balance favours the development — the guidelines themselves acknowledge that higher-density urban contexts may justify more flexible application. However, significant transgressions without adequate justification are likely to attract officer concern and neighbour objection.
What is the difference between a daylight assessment and a right to light survey?
A daylight and sunlight assessment is a planning document that evaluates the impact of a proposed development against the BRE guidelines. It is submitted to the LPA as part of the planning application and deals with amenity considerations. A right to light survey is a legal assessment of whether the proposed development would interfere with a prescriptive right to light enjoyed by a neighbouring property under the Prescription Act 1832. A right to light is a private legal right, enforceable by injunction or damages, and is entirely separate from the planning process. A development can comply with BRE guidelines but still infringe a right to light, and vice versa. Right to light surveys should be carried out by a chartered surveyor experienced in this specialist area.
Legal and regulatory framework
- BRE Report BR 209 (Site Layout Planning for Daylight and Sunlight: A Guide to Good Practice, 3rd edition 2022) — the principal guidance document used by LPAs across the UK to assess daylight and sunlight impacts. It sets out the VSC, daylight distribution, APSH, and sun-on-ground methodologies and numerical benchmarks.
- National Planning Policy Framework (NPPF)
- London Plan Policy D6 (Housing Quality and Standards) — requires that the design of new housing in London demonstrates adequate daylight provision and avoids unacceptable impacts on neighbours. Housing Design Standards LPG provides further guidance.
- BS EN 17037:2018 (Daylight of Buildings) — a European (and British) Standard that provides a more modern, climate-based framework for daylight assessment. Some LPAs are beginning to request assessments against BS EN 17037 in addition to or instead of BRE criteria.
- Prescriptive right to light
- Rights of Light Act 1959
Professional accreditations
- Society of Light and Lighting