Daylight & Sunlight Assessment

BRE 209 (2022) — VSC, daylight distribution, sunlight hours, and right to light screening

Proposed Development

Building Height (metres)

Height of proposed building to eaves or top storey

Number of Storeys

Building Width/Frontage (metres)

Building Depth (metres)

Primary Use

Primary Orientation

Affected Property (Neighbour)

Distance from Proposed Building (metres)

Distance from proposed frontage to affected window

Affected Window Height (metres)

Height of affected window above ground level

Affected Space Use

Affected Floors with Windows

Approximate Number of Affected Windows

Existing Context

Height of Existing Building Being Replaced (metres)

0 if greenfield or no existing building

Urban Context

Street Width Between Buildings (metres)

BRE 209 Tests to Screen

Select which assessments to include:

Vertical Sky Component (VSC)

No Sky Line / Daylight Distribution (NSL)

Annual Probable Sunlight Hours (APSH)

Sun on Ground / Amenity Areas

Room Details (for Daylight Distribution Assessment)

Affected Room Depth from Window (metres)

Typical: 5m for residential

Affected Room Width (metres)

Typical: 4m for standard window

Amenity Space (for Sun on Ground Assessment)

Amenity Space Area (sqm)

0 if no amenity space affected

Amenity Space Orientation

About this tool: Daylight & Sunlight

BRE 209 (2022 edition) assessment — Vertical Sky Component, daylight distribution, Annual Probable Sunlight Hours, and the 25-degree check.

When to use it

Use when your development is close to existing windows, or when neighbouring objections about loss of light are likely. Critical for infill, extensions, and taller buildings.

Policy and guidance it draws on

BRE Report 209 (2022), NPPF living conditions policy P3

Part of Design Intelligence

Use these tools when designing your scheme or reviewing drawings. They help ensure your proposal meets technical standards before submission, reducing the risk of officer objections on design grounds.

Guidance to help you prepare — not formal planning advice. Check the current policy text and your council's local plan before relying on it.