A daylight and sunlight report in the UK typically costs between roughly £500 and £2,500 plus VAT for a straightforward residential scheme, with larger or contested schemes running well into four or five figures. The honest answer, though, is that there is no fixed price — the figure depends on what is being assessed, how many neighbouring windows are involved, and which tests the local planning authority expects to see.
This guide explains what drives the cost of a daylight report, what you should expect to pay in 2026, and how to budget sensibly so you neither overpay for a gold-plated study you do not need nor under-scope a report that the council later rejects. If you are still unsure what one of these reports actually is, our explainer on what a daylight report is and when you need one is the place to start.
What you are actually paying for
A daylight and sunlight report is not a single, standardised product. It is a piece of technical analysis carried out by a consultant against the BRE BR 209 (2022) guidance and, for internal daylight in new homes, BS EN 17037. The fee covers a surveyor's time, the 3D massing model of your scheme and its surroundings, the calculations themselves, and a written report your planning officer can rely on.
Broadly, the work falls into two categories, and many projects need both:
- Impact on neighbours — whether your proposal reduces daylight or sunlight to surrounding properties, measured through Vertical Sky Component (VSC), No-Sky Line (NSL) and the Annual Probable Sunlight Hours (APSH) tests. Our guide to VSC, NSL and APSH walks through each one.
- Internal daylight — whether the rooms inside your own new or converted units receive adequate light under BS EN 17037 and the BRE provision tests.
The more windows, rooms and neighbouring properties in play, the more modelling and reporting time is required — and that is the single biggest lever on price.
Typical UK daylight report costs in 2026
As a realistic guide for 2026, the following ranges reflect what most UK consultancies charge, excluding VAT:
| Project type | Indicative fee (ex VAT) |
|---|---|
| Single rear or side extension (one or two affected neighbours) | £500 – £1,000 |
| Loft conversion or single new dwelling | £600 – £1,200 |
| Small block of flats / office-to-residential conversion | £1,200 – £3,000 |
| Larger or multi-storey residential scheme | £3,000 – £8,000+ |
| Major or contested development with rebuttal evidence | £8,000 – £20,000+ |
These figures sit broadly in line with wider industry guidance. Architecture for London's 2026 cost update, for instance, suggests budgeting upwards of £2,000 for sun and daylight assessments on a typical project, with specialist consultant input on complex sites adding several thousand pounds more. Costs climb where a scheme is in a conservation area, has been refused before, or raises significant overlooking and overshadowing concerns.
Treat any single quote as a starting point rather than a fixed tariff. Two consultants can quote very differently for the same building simply because they have scoped the work differently — one assuming a quick neighbour-impact screening, another a full internal-and-external study with a planning statement.
The factors that move the price
1. Number of neighbouring windows
Each window on a surrounding property that could be affected has to be located, modelled and tested. A mid-terrace extension with two affected neighbours is quick; a corner plot overlooked by a dozen flats is not. This is usually the dominant cost factor.
2. Whether internal daylight is assessed
If you are creating new habitable rooms — flats, an office-to-residential conversion, or a basement conversion — the consultant also models internal daylight under BS EN 17037. That roughly doubles the modelling effort compared with a neighbour-impact-only study.
3. Site complexity and surroundings
A flat, well-documented suburban plot is cheap to model. A sloping site, a dense urban context with tall neighbours, or a building with complex geometry all add survey and modelling time. Conservation areas and listed settings can also require additional justification.
4. The council's expectations
Some authorities ask only for a short screening note; others, particularly in London, expect a full BRE assessment with detailed appendices. London boroughs frequently apply the most demanding standards — see our overview of London Plan daylight standards in 2026.
5. Whether the scheme passes first time
If your design already meets BRE targets, the report is a clean statement of compliance. If it fails, you may need mitigation advice, redesign iterations, or an Appendix F alternative-target justification — all of which add cost. Our mitigation playbook explains the options when a scheme falls short.
6. Turnaround speed
Standard turnaround is usually around a week. If you need a report in 48 hours to meet a planning deadline, expect a premium.
Why the cheapest quote is rarely the best value
It is tempting to pick the lowest number, but a daylight report is evidence that has to stand up to a planning officer — and, on appeal, to a planning inspector. A report that is too thin, uses out-of-date 2011 BRE methodology, or misses a key neighbour can trigger a refusal that costs you far more than the few hundred pounds you saved. If your application is refused, the route back is slow and expensive; our piece on overturning a refusal on appeal shows why getting it right first time matters.
Good value means a report that is correctly scoped for your scheme, uses current BRE BR 209 (2022) methodology, and gives your planning officer everything they need to say yes. Sometimes that is the cheap quote; often it is not.
How to budget without overpaying
- Get the scope in writing. Ask exactly what tests are included — neighbour impact only, or internal daylight too?
- Ask early. A daylight check at concept stage can flag problems while they are still cheap to fix in the design, rather than after you have paid for full drawings.
- Provide good information. Accurate existing drawings and a measured survey reduce the consultant's time and therefore your fee.
- Confirm the council's requirements. A quick pre-application enquiry can tell you whether a full assessment is even needed.
- Watch the VAT. Most published fees exclude VAT — factor it in.
For homeowners weighing the fee against the value of the project, our article on right to light versus a daylight report is also worth reading, because the two are often confused and address very different risks.
How Fortress Associates can help
At Fortress Associates we prepare BRE BR 209 (2022) and BS EN 17037 compliant daylight and sunlight reports for projects across the UK, from single extensions to multi-unit residential schemes. We scope each report to what your scheme and your local authority actually require, so you are not paying for analysis you do not need. Our standard turnaround is 4–5 working days, and we take no advance payment. To get a clear, fixed quote for your project, get in touch with the proposed drawings or address, or read more about our daylight and building regulations services.
Sources & further reading
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