Internal daylight and sunlight assessments

Internal Daylight & Sunlight Assessments: A Complete Guide

Vertical Sky Component VSC Context

Vertical Sky Component (VSC) Explained

What Is a Daylight and Sunlight Assessment

What Is a Daylight and Sunlight Assessment?

Daylight & Sunlight Glossary

Daylight & Sunlight Glossary: VSC, NSL, APSH and Key Terms

Overshadowing Studies

Overshadowing Studies – How They Affect Planning

Understanding BRE 209

Understanding BRE 209 (2022): The Latest Daylight and Sunlight Guidance

Daylight Factors and BS EN 17037

Daylight Factors and BS EN 17037: Understanding Internal Daylighting Standards

BRE 45 Degree Rule

BRE 45 Degree Rule: Quick Check for Domestic Extensions and Daylight

Climate Based Daylight Modelling

What is Climate Based Daylight Modelling?

Daylight and Sunlight Gardens and Amenity Spaces

Daylight and Sunlight Gardens and Amenity Spaces: BRE Guidance for Outdoor Areas

Solar PV Roofs Not Fields

Solar PV : Roofs Not Fields

Rights to Light Rise of Radiance

Rights to Light – Rise of Radiance

Balconies Impact Daylight & Sunlight

Balconies Impact on Daylight & Sunlight

Daylight and Sunlight Asessment London

Daylight and Sunlight Assessment London

Room Layouts Affect Daylight & Sunlight

How Room Layouts Affect Daylight & Sunlight

Dayight and Sunlight BRE Guidelines

Daylight and Sunlight – BRE Guidelines

Daylight & Sunlight Assessment Solar Panels

Daylight and Sunlight Assessment Solar Panels

Annual Probable Sunlight Hours (APSH) Explained

No Sky Line

No Sky Line (NSL) Explained

Class MA Permitted Development

Daylight Design

Daylight Design: Enhancing Co-Living

Daylight & Sunlight Appeals Westland Place Hackney

Daylight & Sunlight Appeal – Westland Place Hackney

Solar Panels Protecting Investment

Solar Panels : Protecting Investment

Berkeley House Planning Appeal

Judicial Review Watt v Hackney

Judicial Review Watt v Hackney – A Detailed Case Summary

Plans Approved for 85 Gracechurch

Plans Approved for 85 Gracechurch Street

85 Gracechurch Street

Plans submitted for 85 Gracechurch Street

New BRE Guidelines Daylight and Sunlight

New BRE Guidelines on Daylight & Sunlight 2022

Daylight & Sunlight Birmingham

New Birmingham Daylight & Sunlight Assessments

Daylight & Sunlight Dagenham Dock

GIA Surveyors

GIA Surveyors ‘Misleading Advice’

Daylight & sunlight Royal Docks Masterplan

Royal-Docks-Masterplan

Royal Docks Masterplan Approved

European Standard for Daylighting EN17037

New European Standard for Daylighting EN17037

Rights to Light Case Law Scott v Aimiuwu

Judge Quashes Planning over ‘Materially Misleading’ Daylight & Sunlight report

Daylight Error Fatal to Planning Permission

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.

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 <a href="https://www.ansteyhorne.co.uk/news/vertical-sky-component-vsc">Vertical Sky Component</a> (VSC).

Daylight to neighbouring rooms using <a href="https://www.ansteyhorne.co.uk/news/no-sky-line">No-Sky Line (NSL) / Daylight Distribution</a>.

Sunlight to neighbouring windows using <a href="https://www.ansteyhorne.co.uk/news/annual-probable-sunlight-hours-apsh">Annual Probable Sunlight Hours (APSH)</a>, including winter.

Overshadowing of <a href="https://www.ansteyhorne.co.uk/news/daylight-and-sunlight-gardens-and-amenity-spaces-bre-guidance-for-outdoor-areas">gardens and public amenity spaces</a>.

<a href="https://www.ansteyhorne.co.uk/news/internal-daylight-sunlight-assessments-a-complete-guide">Internal daylight to proposed dwellings</a>, often using <a href="https://www.ansteyhorne.co.uk/news/what-is-climate-based-daylight-modelling">climate-based daylight modelling</a> (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 &amp; 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 &amp; heritage adjacencies often require a tighter, more sensitive approach with early massing optimisation and clear narrative on why remaining shortfalls are reasonable.

Street canyons &amp; 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)

We calculate <a href="https://www.ansteyhorne.co.uk/news/vertical-sky-component-vsc">Vertical Sky Component</a> 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 <a href="https://www.ansteyhorne.co.uk/news/no-sky-line">No-Sky Line</a> 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.

We report<a href="https://www.ansteyhorne.co.uk/news/annual-probable-sunlight-hours-apsh"> annual and winter APSH</a> 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.

For <a href="https://www.ansteyhorne.co.uk/news/daylight-and-sunlight-gardens-and-amenity-spaces-bre-guidance-for-outdoor-areas">gardens, playgrounds and public realm</a>, 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 <a href="https://www.ansteyhorne.co.uk/news/internal-daylight-sunlight-assessments-a-complete-guide">demonstrate usability and liveability</a>, especially in deeper plans or ground-floor units shielded by surrounding massing.

Who Needs a Daylight and Sunlight Assessment?

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.

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

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 &amp; 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 &amp; Sunlight Assessment Services in London

<a href="https://www.ansteyhorne.co.uk/services/daylight-and-sunlight-assessment">Detailed Daylight &amp; Sunlight Assessments</a>

Maximum Development Envelopes &amp; Optimisation

<a href="https://www.ansteyhorne.co.uk/news/internal-daylight-sunlight-assessments-a-complete-guide">Internal Daylight &amp; Sunlight Assessment</a>

<a href="https://www.ansteyhorne.co.uk/news/daylight-and-sunlight-gardens-and-amenity-spaces-bre-guidance-for-outdoor-areas">Hours in Sun for Amenity Space</a>

<a href="https://www.ansteyhorne.co.uk/news/what-is-climate-based-daylight-modelling">Climate Based Assessment</a>

<a href="https://www.ansteyhorne.co.uk/services/solar-glare">Solar Glare</a>

<a href="https://www.ansteyhorne.co.uk/services/solar-panel-assessments">Solar Panel Assessments</a>

Technical adviser to Local Planning Authorities

<a href="https://www.ansteyhorne.co.uk/news/new-bre-guidelines-daylight-and-sunlight">New British Standard EN17037 View Out Assessment</a>

For advice on daylight assessments from one of our London surveyors, please call our Enquiry line in <a href="tel:020%204534%203138">020 4534 3138</a>.

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 <a href="https://www.ansteyhorne.co.uk/news/daylight-sunlight-dagenham-dock">Dagenham Dock</a>, <a href="https://www.ansteyhorne.co.uk/projects/daylight-sunlight-harrow-road">Harrow Road </a> and <a href="https://www.ansteyhorne.co.uk/projects/daylight-sunlight-stevenage-town">Stevenage Town Centre</a>.

For more information on all aspects of a Daylight and Sunlight Assessments see the <a href="https://www.ansteyhorne.co.uk/blogs/daylight-and-sunlight-assessment-london">collection of articles on our blog page</a>.

For details of our specialist Daylight &amp; Sunlight surveyors near you see our <a href="https://www.ansteyhorne.co.uk/services/daylight-sunlight-birmingham">Birmingham</a>, <a href="https://www.ansteyhorne.co.uk/services/daylight-sunlight-manchester">Manchester</a>, <a href="https://www.ansteyhorne.co.uk/services/daylight-and-sunlight-assessment-bristol">Bristol</a>, <a href="https://www.ansteyhorne.co.uk/services/daylight-and-sunlight-assessment-brighton">Brighton</a>, <a href="https://www.ansteyhorne.co.uk/services/daylight-and-sunlight-assessment-norwich-2">Norwich </a>&amp; <a href="https://www.ansteyhorne.co.uk/contact-us#plymouth">Plymouth</a> office details.

Contact us

For advice on Daylight &amp; Sunlight direct from one of our surveyors, please call our Enquiry Line on <a href="tel:020 4534 3138">020 4534 3138</a>.
If you would like us to call you, please fill in our <a href="https://www.ansteyhorne.co.uk/contact-us#contact">Contact Us</a> form and we will call you back.

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