Daylight Assessments London

BRE-compliant daylight assessments for London planning. We help architects, developers and planning consultants navigate dense urban constraints, optimise massing, and secure consents across London boroughs.

Our reports are trusted by planning officers because we explain the methodology clearly, model realistic site conditions, and present balanced advice that protects amenity while enabling viable development.

Why choose Anstey Horne for Daylight Assessments in London

When a London scheme is tight on massing or sensitive on context, daylight and sunlight becomes a decisive planning issue. We combine deep technical modelling with practical planning experience to deliver officer-ready submissions that stand up to scrutiny. You’ll get:

A single accountable Director level surveyor (named in the report) who signs off the methodology and results.
BRE 209 (2022)-aligned analysis with clear commentary on flexibility in dense urban contexts.
Sensitivity testing and mitigation options (e.g. façade articulation, setbacks, lightwells).
Executive summary formatted for case officers, with schedules and drawings logically tabbed.
Swift turnarounds for pre-apps and fast quotes with a clear scope.

What Is a Daylight Assessment?

A daylight assessment evaluates the impact of a proposed development on the daylight and sunlight amenity of surrounding properties (and, where relevant, the adequacy of daylight within the proposed accommodation). For London schemes, the assessments typically address:

Daylight to neighbouring windows using Vertical Sky Component (VSC).
Daylight to neighbouring rooms using No-Sky Line (NSL) / Daylight Distribution.
Sunlight to neighbouring windows using Annual Probable Sunlight Hours (APSH), including winter.
Overshadowing of gardens and public amenity spaces.
Internal daylight to proposed dwellings, often using climate-based daylight modelling (CBDM) or daylight factor proxies where requested by the LPA.

Results are interpreted with reference to BRE 209 (2022), which is guidance not policy, and can be applied flexibly where design quality, urban form and wider planning benefits justify it - particularly relevant across London’s high-density settings.

Why London schemes need a London-specific approach

London boroughs face intense pressures: heritage setting, townscape views, constrained plots, air rights and rooftop extensions, tall-building clusters, and small-site infills. That means context-led professional judgment is vital:

Opportunity Areas & growth corridors may accept a higher degree of daylight change if the overall planning benefits are strong and baseline conditions are already limited.
Conservation areas & heritage adjacencies often require a tighter, more sensitive approach with early massing optimisation and clear narrative on why remaining shortfalls are reasonable.
Street canyons & mixed urban typologies (mews infill, podiums, perimeter blocks) need careful window referencing, façade articulation and realistic boundary modelling to avoid over-promising or under-testing.

Our London daylight assessments explain these trade-offs plainly and evidence them with clear drawings, tables and photographs so case officers can rely on the conclusions.

Key metrics we use (and how we present them)

Daylight to neighbours: VSC

We calculate Vertical Sky Component at the middle of each relevant window to assess the change in sky visibility caused by the proposal. We tabulate existing, proposed and percentage change, highlight material reductions, and cross-reference the associated room where known.

Daylight to neighbours: NSL (Daylight Distribution)

Where room depths and layouts are available or reasonably inferred, we test No-Sky Line to show the proportion of the working plane that remains with a view of the sky. We always explain assumptions and limit inference risk where plans are incomplete.

Sunlight to neighbours: APSH

We report annual and winter APSH for relevant windows with a southerly aspect. We identify whether any windows fall below BRE advisory values and, if so, whether they retain adequate sunlight or have limited potential due to orientation and urban context.

Overshadowing of amenity spaces

For gardens, playgrounds and public realm, we illustrate the two-hours sun test across the Spring Equinox. Where overshadowing increases, we explain whether more than 50% of the area still receives two hours of sun, or whether alternative design responses are warranted.

Internal daylight (proposed accommodation)

Depending on local planning authority preference and design stage, we undertake CBDM (e.g., sDA/UDI) or daylight factor-based screening to demonstrate usability and liveability, especially in deeper plans or ground-floor units shielded by surrounding massing.

Who Needs a Daylight and Sunlight Assessment?

You will likely need an assessment if:

Your proposed development is near residential buildings
You’re submitting a planning application for a new building, extension, or change of use
The scheme could potentially reduce daylight or sunlight to neighbouring properties
The local planning authority has requested one

Our reports are frequently submitted as part of planning applications across all London boroughs, with particular experience in high-density, sensitive, and heritage contexts.

Why Choose Anstey Horne for Daylight Assessment in London?

We are one of the UK’s most experienced consultants in the field of daylight and sunlight. With a heritage spanning over two centuries, Anstey Horne combines deep technical knowledge with an in-depth understanding of planning policy and urban design.

Our London-based team delivers:

Clear and reliable reports tailored to your project
Fully compliant assessments in accordance with BRE, BS EN 17037 and local authority standards
Expert witness services and strategic advice
Fast turnaround and transparent pricing

Typical London project scenarios we support

Rooftop and air-rights additions to existing blocks, including prior approvals progressing to planning.
Tight infill between party walls, mews and backland plots.
Perimeter blocks & podiums in emerging tall-building clusters, with complex overshadowing.
Mixed-use schemes where back-of-house and plant interfaces constrain residential daylight.
Heritage adjacencies where façade rhythm and fenestration alignment reduces risk of localised losses.
Estate regeneration with staged baselines (existing, interim, consented masterplans).

Daylight & Sunlight Assessment Services in London

Contact - Daylight Assessments in London

For advice on daylight assessments from one of our London surveyors, please call our Enquiry line in 020 4534 3138.

We cover all of London and the South East. We have live Daylight and Sunlight projects in London, Brighton, Hastings, Canterbury, Chichester and Guildford.

See links to our recent projects in London at Dagenham Dock, Harrow Road  and Stevenage Town Centre.

For more information on all aspects of a Daylight and Sunlight Assessments see the collection of articles on our blog page.

For details of our specialist Daylight & Sunlight surveyors near you see our Birmingham, Manchester, Bristol, Brighton, Norwich & Plymouth office details.