How to read a BRE daylight and sunlight report

A BRE 209 daylight and sunlight report is a long technical document, but it has a predictable structure and only a few sections really need careful reading. The order is: executive summary, methodology, receptor schedule, then the VSC, NSL and APSH tables, followed by shadow plans and appendices. For a reader with a specific home to check, the route is receptor schedule first, VSC/NSL/APSH tables second, shadow plans third — and the executive summary last, because by then you can judge whether the summary matches the numbers.

Where to find the report

BRE 209 reports are uploaded to the planning portal as supporting documents to a major application. They are usually titled Daylight, Sunlight and Overshadowing Assessment, sometimes Daylight/Sunlight Report or BRE Assessment. Look for a PDF of 60 to 400 pages. They are most often prepared by a dedicated consultancy (Point 2, GIA, Schroeders Begg, Anstey Horne, Avison Young Rights of Light).

The sections, in reading order

1. Receptor schedule

Read this first. The receptor schedule lists every window on every neighbouring building the applicant has assessed. If your window is not in the schedule, none of the numbers in the rest of the report apply to your home.

The schedule typically gives, per window:

• A unique receptor ID (R1, R2, W1F2, etc.)
• The address and property name
• Floor level (ground, first, second, etc.)
• Room use (living room, bedroom, kitchen, study, non-habitable)
• Orientation of the window
• Aperture size (for VSC)

Four checks to do:

1. Is your address listed?
2. Is every window facing the proposal included? Bay windows count as one or more receptors; dormer windows are frequently missed.
3. Is the room use correct? A kitchen-diner classified as "non-habitable utility" or "kitchen" (rather than "kitchen/living") will be softly-tested or not tested at all.
4. Is the floor level correct? A garden flat listed as "lower ground" and a basement listed as "non-habitable" are the classic classification errors.

2. VSC table

Find the VSC table (usually labelled "Vertical Sky Component — Summary of Results" or similar). Columns you want:

• Receptor ID and address
• Existing VSC (%)
• Proposed VSC (%)
• Ratio (proposed / existing)
• BRE compliance flag (pass / fail / noticeable / significant)

Scan the ratio column for values below 0.8. These are the receptors that BRE treats as noticeable. Values below 0.7 are significant and should be discussed explicitly in the officer's report.

See our full note on VSC for the thresholds and how to challenge the numbers.

3. NSL (Daylight Distribution) table and plans

NSL is reported in two places: a table (one row per room) and a set of plans (one per affected floor). The table shows existing lit area (m²), proposed lit area (m²) and the ratio. The plans show the NSL contour drawn on a room layout.

Check that the room areas and the room boundaries look right against the plan. A deep-plan room with a tall close obstruction is the geometry to watch. See the note on NSL for details.

4. APSH table

APSH is reported only for living-room windows facing within 90 degrees of south. If your window is in the schedule but not in the APSH table, check the orientation filter.

The APSH table usually has four numeric columns: APSH-annual existing, APSH-annual proposed, APSH-winter existing, APSH-winter proposed. Make sure both annual and winter figures are reported. See our APSH guide for the 25% / 5% / 0.8 thresholds.

5. Shadow / overshadowing plans

For schemes that affect gardens, parks, play space or public realm, look for a set of shadow plans. These typically show hourly shadows on a single day (21 March, the equinox, is the BRE benchmark), either as a series of snapshots or as a sweep. Check that any garden adjoining your home is included in the analysis area. See shadow analysis at the equinox.

6. Cumulative assessment

Many reports include a cumulative assessment alongside the base case. The cumulative baseline adds other consented-but-unbuilt schemes to the existing condition, reducing the apparent loss from the proposal on its own. Read carefully: the cumulative VSC ratio can look much better than the proposal-only ratio, but the cumulative condition depends on other schemes actually being built, which is not guaranteed.

7. Executive summary

Read the executive summary last. By this point you will know the real picture from the tables. The summary is the applicant's framing; the tables are the evidence. Compare the two. A summary that says "the proposal is broadly compliant with BRE guidance" when 30% of receptors have VSC ratios below 0.8 is a summary that is trading on the absence of an absolute threshold.

8. Appendices

Typical appendices include:

• Full receptor schedule (often a cross-reference back to section 1)
• Full VSC, NSL, APSH tables (repeating or extending the summary tables)
• Site and context plans with receptor IDs marked
• Massing diagrams of the baseline, proposed and cumulative cases
• Photographs of the affected windows (where survey access was granted)

The photographs appendix is worth a look: where the applicant has survey access to a property, the photographs show which rooms they believed they were assessing. Sometimes a room use is misclassified in the schedule but the photograph makes the true use obvious.

The five most common errors

1. Missing receptors. Windows on the flanks of a building, dormer windows, windows at basement or attic level, and windows on buildings not shown on OS mapping are the most frequently missed.
2. Wrong room classification. Kitchen-diners classified as "kitchen" (lighter APSH treatment); living-dining rooms split into two notional rooms (softening NSL); "studies" declared as non-habitable.
3. Cumulative baseline inflating obstruction. The inclusion of large unbuilt schemes in the baseline sometimes reduces the apparent impact of the subject scheme to near zero. Always ask for the proposal-only figures separately.
4. Understated window-head heights. Where survey access was refused, applicants sometimes assume a generic head height that is lower than the true value. This pulls the NSL towards the window and softens the loss.
5. Selective summary. A summary table that reports only the ratio can hide the fact that the absolute VSC or APSH has fallen below the BRE target. Always check the absolute values as well as the ratios.

How to cross-check against your actual windows

1. Locate your building on the site plan (usually the first context plan in the appendix). Note the receptor IDs shown on your facade.
2. For each ID, find the row in the VSC, NSL and APSH tables. Record the four VSC numbers and the four APSH numbers per window.
3. Draw a one-line summary per window in your own notes: "Flat 12, living-room window. VSC 28 → 14 (ratio 0.50). APSH 28% → 9% (ratio 0.32)."
4. Compare against the BRE thresholds (27% VSC absolute; 0.8 ratio; 25% APSH-annual / 5% winter). Circle any failure.
5. Write the objection paragraph using the numbers verbatim and citing the page and table in the report.

Putting the report numbers into an objection

Once you have the numbers, an objection paragraph looks like this:

"The Daylight and Sunlight Assessment (Appendix 3, Table VSC-2, receptor R163) reports a reduction in VSC at the living-room window of Flat 12, 22 local road, from 28.4% to 14.1%, a ratio of 0.497. This ratio falls below the BRE 209 threshold of 0.7 for a significant effect. The scheme therefore conflicts with London Plan Policy D6 and the relevant borough Local Plan policies on residential amenity, and should be refused on daylight grounds."

The four components — precise receptor reference, the numbers verbatim, the BRE threshold, and the policy citation — are what makes the objection actionable. See our step-by-step guide to formal objections.

Frequently asked questions

What is a BRE daylight and sunlight report?
A technical document, usually appended to a major planning application, reporting how the proposal affects daylight, sunlight and overshadowing at neighbouring properties under BRE 209.

Which section should I read first?
The receptor schedule. If your windows are not in the schedule, the report's numbers do not describe your home.

Where are the numbers that matter?
The VSC, NSL and APSH tables. Scan the ratio columns for values below 0.8, and the APSH columns for absolute values below 25% or winter values below 5%.

What are the most common errors?
Missing windows, wrong room classifications, overstated cumulative baseline, understated window-head heights, and selectively-framed executive summaries.

Sources