Daylight and Sunlight Assessments in Richmond

In Richmond upon Thames the jobs that land on our desk are mostly householder schemes: 3m and deeper rear extensions on the Victorian terraces of Twickenham, St Margarets and East Sheen, side extensions and dormers on the semi-detached streets of Teddington, Hampton and Whitton, and the occasional office-to-flats conversion in Richmond town centre. The borough's gardens are narrow and its rear elevations close together, so an extension that is unremarkable in size can still take a measurable slice of sky from the kitchen next door.

What is distinctive about Richmond is how often the request for a report comes mid-application. A case officer applies the 45-degree check from the council's house extensions guidance, finds the scheme breaches it on plan, and asks the applicant for a daylight test showing the neighbour keeps at least 80% of its light. The application clock is already running, so these reports are usually needed within days rather than weeks.

Recent daylight and sunlight assessments in Richmond upon Thames

10 Cross Deep Gardens, Twickenham, TW1: 3m rear extension

A single-storey rear extension, 3m deep, next to the matching houses at 8 and 12 Cross Deep Gardens. The drawings showed it crossing the 45-degree line from the neighbour's nearest window, and the case officer asked for a proper daylight test before the application could be determined. The 45-degree rule is only a rough plan-based screen: the full VSC and APSH tests showed every window at both neighbours within the BRE daylight and sunlight guidelines, with no design change needed. Application PA25/2526 was granted permission on 20 October 2025.

39 Kingston Lane, Teddington, TW11: dormers, rear gable and side extension

Side and front dormers, a rear roof gable extension and a side extension to a semi-detached house, with the two adjoining houses tested. The side elevation of No. 37 sat in shadow on every aerial image, so its window positions could not be confirmed from the desk; rather than guess, we used site photographs of the flank wall to confirm them before the report was finalised. Every neighbouring window met the daylight and sunlight guidelines.

Application PA25/1852 was granted permission on 31 July 2025.

York Road, Richmond, TW10: rear extensions and loft dormers to a terrace

Rear and ground-floor extensions with loft dormers to a terraced house. The owner wanted to show the council and the neighbours that the daylight to the rear windows of the houses either side would not be reduced, and that the extension would screen existing overlooking. Every rear window at both neighbours met the BRE daylight and sunlight guidelines, and still did when a rear ground-floor infill was added. Rendered views of the extension and the neighbouring house illustrated the privacy point. The report was issued in November 2024.

What Richmond planning officers look for

Richmond determines applications against the Richmond Local Plan 2024 to 2039, adopted on 7 October 2025, which carries forward the borough's strong emphasis on protecting residential amenity and the character of its conservation areas. For daylight and sunlight the council applies BRE 209, Site layout planning for daylight and sunlight (2022 edition).

For extensions and alterations the working document is the House Extensions and External Alterations SPD. It sets out the 45-degree and 25-degree checks officers use as a first screen, and where a scheme breaches them the SPD points to a BRE assessment as the way to show that the neighbour's light is still acceptable. The Design Quality SPD and the Residential Development Standards SPD cover amenity expectations for larger schemes and new homes. The Local Plan is at richmond.gov.uk/services/planning/planning_policy/local_plan/adopted_local_plan and the SPDs at richmond.gov.uk/services/planning/planning_policy/supplementary_planning_documents_and_guidance.

When you need an assessment in Richmond upon Thames

• Rear extensions of 3m or more on the terraces of Twickenham, St Margarets, East Sheen and Mortlake, especially where the neighbour's kitchen window is close to the boundary
• Any householder scheme where the case officer has written to say it breaches the 45-degree rule and a daylight test is required
• Side extensions, rear gables and dormers on the semi-detached streets of Teddington, Hampton, Whitton and Ham
• Infill and wraparound extensions in the Kew and Richmond Hill conservation areas, where amenity is weighed alongside heritage
• Class MA conversions of offices in Richmond and Twickenham town centres, where the new flats' own daylight must be shown
• Schemes where a neighbour has already raised a concern about light and you want the figures before the committee or officer report

How we work

Send us the drawings and a few photographs and we build the 3D model of your house, the neighbours and the street ourselves. The fee is fixed and agreed before we start, and a report usually takes 4–5 working days; when an officer has set a deadline, tell us and we will say honestly whether we can meet it. Our daylight and sunlight assessment page describes the service. Each report covers the four BRE tests:

• VSC for daylight at each neighbouring window
• NSL for daylight distribution inside the rooms
• APSH for annual and winter sunlight to windows facing within 90 degrees of south
• Sun on ground for gardens on 21 March

Read more on our VSC, NSL and APSH and BRE guidelines pages.

Frequently asked questions in Richmond upon Thames

The officer says my extension breaches the 45-degree rule. Is the application lost?

No. The 45-degree line is a screening tool drawn on plan; it does not measure sky. At Cross Deep Gardens the scheme crossed the line but the neighbours kept their daylight and sunlight within the BRE guidelines. A full VSC and APSH test is what the officer is asking for, and it is often the answer.

Does Richmond ask for a shadow study for a single-storey extension?

Rarely. For a single-storey rear extension the council is usually satisfied with the window tests and the 21 March sun-on-ground test for the neighbour's garden. Shadow plots are more often requested for two-storey or multi-unit schemes, and we add them when they help.

You cannot see my neighbour's side windows. How do you test them?

We check planning history, aerial and street imagery first. If the flank wall is still unclear, as at Kingston Lane, we ask you for a photograph from your garden rather than guess, because a disputed window map undermines an otherwise sound report.

Get a fixed-fee quote

Upload your drawings through our contact page or get an instant figure from the price calculator. For a quick conversation call Nick on 01962 809155 or email nick@sunlightassessments.co.uk; if your site is south of the A3, our Kingston upon Thames page may be the better starting point.