Presenting daylight and sunlight results tables
Case officers judge a daylight and sunlight assessment by its tables. Here is the column order, the room references and the summary structure that survive review.
A daylight and sunlight assessment stands or falls on its results tables. The modelling can be faultless and the conclusion fair, but if a case officer cannot find the affected room, read its before and after figures and see the proportional change on one line, the report comes back with questions. Presenting daylight and sunlight results is a drafting discipline rather than a modelling one, and it is the part most often rushed. The tables described here follow BRE 209 (2022), Site Layout Planning for Daylight and Sunlight, which is the guidance most English authorities ask for by name in a Daylight and Sunlight Assessment.
What a decision maker needs from the table
A case officer is not checking your model. They are checking whether loss of light to neighbouring rooms is material, and whether it sits in a handful of rooms or runs along a whole terrace.
Three things therefore have to be visible without cross-referencing: which property and which room, what the figure was before, and how far it moves. Everything else is supporting detail that belongs in an appendix.
State the numerical tests once, in plain words, before the first table. Vertical sky component uses 27 per cent as the reference figure at the centre of a window, with the proportional test treating a retained value of 0.8 or more of the former figure as unlikely to be noticed. Daylight distribution compares the area of a room that can see the sky before and after, using the same 0.8 proportion. Annual probable sunlight hours apply to windows within 90 degrees of due south, with 25 per cent across the year and 5 per cent between 21 September and 21 March, and a further test on whether the drop exceeds 4 percentage points of annual hours.
Ordering rooms by property, floor and aspect
Order the table the way a person walks the site. Group by address, then by storey from ground upwards, then by window or room reference within the storey. A reader who has just looked at a context plan can follow that without effort.
Number every window and every room on a keyed drawing and use those references in the table verbatim. W12 in the table has to be W12 on the plan, not "first floor rear window". Where a room is served by two windows, say so in the room row and keep the window rows beneath it, because vertical sky component is a window measure and daylight distribution is a room measure. Mixing the two in one column is the most common reason an officer asks for the tables to be reissued.
Include the compass aspect of each window. It explains at a glance why a north-facing kitchen shows no sunlight results at all, and it saves the same question being asked in consultation.
Reporting existing, proposed and proportional change together
One row, one room or window, four numbers. Existing value, proposed value, the ratio of proposed to existing, and a pass or fail against the relevant test.
| Property and room | Window | VSC existing (%) | VSC proposed (%) | Proposed/existing | BRE test |
|---|---|---|---|---|---|
| 12 Mill Road, ground floor living room | W1 | 31.2 | 26.8 | 0.86 | Met |
| 12 Mill Road, ground floor living room | W2 | 28.4 | 19.1 | 0.67 | Not met |
| 14 Mill Road, first floor bedroom | W7 | 34.0 | 33.1 | 0.97 | Met |
That table is illustrative, built to show the column order rather than to describe any real site. The ratio column matters more than the raw values, because the guidance is written around proportional change, and a reader scanning for numbers below 0.80 can find every affected window in seconds.
Round to one decimal place and keep it consistent. Do not report a proposed value to two decimals and an existing value to none.
Flagging the rooms that fall outside the guidance figures
Shade or mark the failing rows, and say in the legend exactly what the mark means. A footnote reading "values below 0.8 of the former figure shown in bold" is enough.
Then write a short paragraph under each table naming the failures in words. Officers quote report text in committee papers, and they quote sentences rather than cells. A sentence such as "two of the 34 windows assessed fall below the proportional test, both serving the same ground floor living room at 12 Mill Road" is the sentence that ends up in the recommendation.
Resist the urge to explain away each failure in the table itself. The commentary sits below, where you can set out the existing constraint, the room layout, the alternative windows and whatever else makes the loss more or less serious than the bare figure suggests.
Bedrooms, kitchens and the rooms that carry less weight
BRE 209 is explicit that its figures are guidance rather than a rule, and that the weight given to a room depends on its use. Living rooms and kitchen dining spaces matter more than bedrooms, and bedrooms matter more than bathrooms, circulation and stores.
Put the room use in its own column and fill it from an observed source: a floor plan on the council's public register, an estate agent particulars sheet, or a site visit with a note of what was seen from the street. Say which. An assumption stated openly survives scrutiny, and an assumption presented as fact does not.
Where you have had to assume, mark the row and repeat the assumption in the commentary. Reviewers dislike surprises much more than they dislike uncertainty.
Summary tables that do not conceal the failures
A summary table is the point at which a report loses credibility fastest. Reporting "94 per cent of windows meet the BRE tests" without a matching count of the rooms that fail invites a consultee to check, find the omission and distrust the rest.
Give both counts, and give them by property. A useful summary has one row per neighbouring address, with the number of windows assessed, the number meeting each test and the range of retained values. The reader can then see that one address carries all the harm, which is usually the fact that decides the application.
Keep the same terminology as the detailed tables. If the detail says "proposed/existing", the summary must not say "percentage retained", because the two look like different measures to someone reading quickly. Repeating the same noun is better writing here than varying it.
Appendices, drawings and cross-referencing
The results tables carry the argument. The appendices prove it, and they need to be findable: the model view showing the assessed elevation, the obstruction drawings, a schedule of surveyed or measured window dimensions and the source of the existing building geometry.
Reference appendices by letter in the table caption rather than in a list at the end. A reader who doubts a single number should reach the evidence for it in one step.
Two habits make the difference in review. First, give every table a caption that names the test, the scenario and the date of the model run. Second, keep a version line on each results page, because schemes change and tables get reused, and a superseded table circulating with a current drawing set is a genuine risk to the applicant.
The same discipline applies to any technical chapter written for a planning audience. It is the reason the ground gas section of a contaminated land assessment is set out as tabulated measurements against criteria, and the reason the lighting section of a landscape strategy tabulates illuminance against environmental zone rather than describing it in prose. Officers compare numbers against thresholds. And they do it quickly, so give them the comparison already made.
Where amenity space rather than windows is at issue, the sun on ground test belongs in a separate table, or in an Overshadowing Study with its own drawings, since it uses a different measure and a different date.
Draft the narrative sections around your results tables on PlanScope and send the finished document to a qualified assessor for review before it goes in.
PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval. This is general guidance, not legal advice; check the position with your local planning authority or a qualified professional before relying on it.
Frequently asked questions
What does the 0.8 rule in BRE 209 mean?
It is a proportional test. If a window or room retains at least 0.8 of its former vertical sky component or its former sky visible area, the guidance treats the change as unlikely to be noticed by the occupier. Below 0.8, the loss is potentially noticeable and needs explaining in the commentary, with the room use and the existing constraint set out.
Should vertical sky component and daylight distribution go in the same table?
Keep them in separate tables or separate blocks of columns. Vertical sky component is measured at a window and daylight distribution is measured across a room, so a single row cannot honestly carry both when a room has two windows. Mixing them is the most common reason an assessment is sent back for reissue.
How do I report a room where I could not confirm the use?
State the assumption in the row and repeat it in the commentary below the table. Say what the assumption rests on, such as a floor plan on the public register or an observation from the highway. Councils accept stated assumptions; they react badly to assumptions that are presented as surveyed fact.
Do I need to report sunlight for every window?
No. Annual probable sunlight hours apply to windows facing within 90 degrees of due south. Put the compass aspect in the table so the reader can see why a north-facing window has no sunlight result, and say once in the method section that windows outside that arc were screened out.
What belongs in the appendices rather than the results tables?
Model views of the assessed elevations, obstruction drawings, the window and room key plan, the schedule of measured dimensions and the source of the existing building geometry. Reference each appendix from the caption of the table it supports, so a reader who doubts one figure reaches the evidence in a single step.
Sources and further reading
This article is general guidance about the planning system in England and, where stated, the rest of the UK. It is not legal or professional advice. Check your local planning authority’s validation requirements and take professional advice for your specific site.