Daylight and Sunlight Assessments in Croydon

Croydon's daylight work splits along the line of the hills. South of the town centre, in Purley, Coulsdon, Kenley, Sanderstead and Selsdon, the plots are wide but the ground is rarely flat: a bungalow gains a first floor and sits a metre or two above the neighbour, or a new house is slotted onto a side plot that falls away towards the road, and the question is what that change in level does to the windows next door. North of the centre, in Addiscombe, Thornton Heath, South Norwood and Norbury, it is the familiar terrace problem of rear extensions and lofts close to a neighbour's outrigger. In the town centre itself, and increasingly around East Croydon and Purley Way, it is tall residential schemes that need a full internal and neighbour study.

Croydon's officers apply Policy DM10.6 of the Local Plan, which requires adequate daylight and sunlight for adjoining occupiers and refers to the BRE guidelines, and they are receptive to a shadow study alongside the numbers when a householder scheme is contested. The two recent jobs below, both in the southern half of the borough, show how we handle a hillside extension and a new house delivered from a BIM model. If you are new to the subject, our main daylight and sunlight assessment page explains what goes into a report.

Recent daylight and sunlight assessments in Croydon

36 Coulsdon Road, Coulsdon, CR5: a bungalow extension with a 21 March shadow study

A first-floor extension and a single-storey rear extension to a bungalow on Coulsdon Road, with a new porch and driveway. The application needed a neighbour-impact report, and we added a shadow study so the officer could see the effect of the new first floor, not just read it in a table. Two windows initially fell short, but they were checked as secondary windows in rooms with other glazing, and the report explained how each room was lit. With the client's permission it is now our public sample report.

The householder application, 25/03684/HSE, was granted permission on 16 March 2026.

1E Riddlesdown Avenue, Purley, CR8: a new house assessed from the architect's own model

A new two-storey house on a plot beside an existing one on Riddlesdown Avenue, with changes to land levels, parking and cycle and refuse storage. The report needed to cover both the neighbours and the new home. We used the architects' own geometry for the proposed massing, so the council saw their design rather than a re-drawn approximation, tested the two neighbouring houses for daylight and sunlight to their windows and gardens, and assessed the new house's rooms internally.

The application, 25/04053/FUL, was granted permission on 6 March 2026.

What Croydon planning officers look for

Croydon's approach to daylight and sunlight is set by the Croydon Local Plan, adopted in 2018. Policy DM10.6 requires development to protect the amenity of adjoining occupiers and to provide adequate sunlight and daylight, and the council refers to the Building Research Establishment guidelines when assessing the layout of development and open space. Officers apply the BRE guidance BR 209: Site layout planning for daylight and sunlight (2022 edition), and because much of the southern half of the borough is suburban they read the benchmarks with regard to local context, as the guidance itself advises.

For householder schemes, Croydon's supplementary planning documents and design guidance explain how the Local Plan policies are applied to extensions and roof alterations. You can find the planning policy pages at croydon.gov.uk/planning-policy and the supplementary planning documents at croydon.gov.uk/supplementary-planning-documents-and-guidance. One Croydon-specific point: where land levels change, officers want to see the existing and proposed ground levels in the model, because a first-floor extension on a plot that sits above its neighbour behaves like a two-storey one from the neighbour's window.

When you need an assessment in Croydon

• First-floor additions to bungalows and chalet bungalows in Coulsdon, Kenley, Old Coulsdon and Selsdon, especially on sloping plots
• New houses on side and garden plots in Purley, Sanderstead and Shirley with neighbours on two or three sides
• Rear extensions and loft conversions on the terraces of Addiscombe, Thornton Heath, South Norwood and Norbury, where the neighbour's outrigger windows are close
• Conversions of houses into flats in West Croydon, Broad Green and Waddon, where the council will want the new rooms tested as well as the neighbours
• Taller residential schemes in the town centre, around East Croydon and along Purley Way, which need a full internal and neighbour study
• Any householder application where a neighbour has raised loss of light and a shadow study would help the officer

How we work

We build a 3D model of the scheme and its neighbours from your drawings, mapping data and photographs, or straight from your Revit, IFC or SketchUp model if you have one, run the BRE tests and tell you the results before the report is written. The fee is fixed and agreed up front, and the report usually takes 4–5 working days from final drawings. The four tests are:

• Vertical Sky Component (VSC): how much sky a neighbouring window can see
• No-Sky Line (NSL), or daylight distribution: how far daylight reaches into the room
• Annual Probable Sunlight Hours (APSH): annual and winter sunlight to windows within 90 degrees of south
• Sun on ground: whether at least half of a garden still gets two hours of sun on 21 March

Our VSC, NSL and APSH page explains each test and our BRE guidelines page sets out the thresholds.

Frequently asked questions in Croydon

Does Croydon ask for a shadow study on a householder extension?

Not as a rule, but officers find it useful when a neighbour has raised overshadowing, and it costs little to add once the model exists. On Coulsdon Road the 21 March shadow images showed the officer the whole day at a glance.

My plot in Purley is higher than my neighbour's. Does the slope matter?

A great deal. The BRE tests are taken from the neighbour's window, so a metre of level difference can add a storey to what that window sees. We model the real ground levels from your topographical survey or the architect's sections, and if the levels are being changed, both the existing and proposed ground are included.

Can you work from our Revit or IFC model?

Yes. IFC, 3D DWG and SketchUp all import; the Riddlesdown Avenue report was built directly from a Stage 5 IFC and delivered in two days.

Get a fixed-fee quote

Send drawings or a model link through our contact page, or get an instant figure from the price calculator. Call Nick on 01962 809155 or email nick@sunlightassessments.co.uk. For sites on the Sutton side of the border around Wallington and Purley Way, see our Sutton page.