Daylight & Sunlight

Daylight and sunlight are key material considerations in planning decisions. Local authorities routinely require assessments to:

• Ensure neighbouring properties retain adequate levels of natural light;
• Confirm that proposed residential units receive appropriate daylight and sunlight;
• Maintain high standards of amenity in urban environments.
• Our reports and advice help unlock development potential while addressing planning policy requirements, BRE guidance, and site-specific constraints.

We also advise on Rights to Light for neighbouring properties.

We provide a full suite of Daylight & Sunlight services tailored to the planning process:

Daylight & Sunlight Impact Assessments

Comprehensive analysis of impacts on neighbouring buildings and gardens using BRE BR209 (2022) and BS EN 17037 methodologies. Delivered as formal reports for submission with planning applications.

Internal Daylighting Analysis

Detailed assessments of daylight provision within proposed habitable rooms, supporting high-quality design and amenity.

Design Development Advice

Early-stage input to inform layouts and massing strategies that align with planning policy while maximising development potential.

Alternative Target Assessments

Justified departures from BRE standards using contextual modelling, particularly in dense urban environments or constrained sites.

Solar Glare & Overshadowing Studies

Impact analysis for neighbouring spaces, private amenity areas, and sensitive receptors, including public realm assessments and APSH calculations.

Appeals and Expert Witness

Expert-led input in planning appeals and public inquiries. We provide clear, evidence-based reports that hold up under cross-examination.

We leverage detailed 3D city models and state-of-the-art analysis tools to provide accurate assessments quickly and efficiently. Our city models for London, Birmingham, Manchester, and other urban centres enable contextual daylight and sunlight studies that go beyond default assumptions.

We routinely assess:

Vertical Sky Component (VSC)

No Sky Line (NSL)

Annual Probable Sunlight Hours (APSH)

Where appropriate, we justify bespoke target values using local context and design-led reasoning.

• Developers – From feasibility to appeal, we help unlock complex sites.
• Architects and Designers – Integrated advice that supports high-quality design.
• Planning Consultants – Robust technical inputs that de-risk applications.
• Local Authorities and Third Parties – Independent assessments and review advice.

• Detailed Daylight & Sunlight Assessments
• Masterplanning & Site Optimisation
• Maximum Development Envelopes & Optimisation
• Façade Analysis & Optimisation
• Internal Daylight & Sunlight Assessment
• Environmental Impact Assessment (EIA)
• Transient Overshadowing
• Hours in Sun for Amenity
• BRE 45 Degree Rule
• Climate Based Assessment
• Tree Impact Assessments
• Radiance Studies
• Solar Glare Assessments
• Light Pollution
• Expert Witness
• Technical adviser to Local Planning AuthoritiesTechnical adviser to Local Planning Authorities
• New British Standard EN17037 View Out Assessment

With the largest dedicated Daylight & Sunlight team in the UK, Anstey Horne leads the industry in planning-focused consultancy. Our advice is commercially aware, technically rigorous, and always planning-policy informed. We tailor every report to meet local planning authority requirements and support successful outcomes.