Evidence pack · England
Sunlight Screening
The BRE first-stage 25° check on all four elevations, measured from the surveyed surface model, with shade figures at the solstices and the equinox.
£39
One-off. Delivered by email within the hour, or refunded automatically if it cannot be produced.
See a real sample — Barbican Estate (PDF)
The question it answers
Before anyone commissions a full daylight and sunlight report, there is a cheaper question: is one likely to be needed at all? BRE’s guidance has a first-stage angular check for exactly that — where an obstruction subtends more than 25° to the horizontal from an affected elevation, the detailed checks are warranted; below it they generally are not.
That angle is pure geometry, and the national LiDAR surface model already knows the height of everything around your site. So this pack measures it — on all four elevations, from the surveyed surface, with the arithmetic shown.
What is in it
- The 25° check on four elevations. North, east, south and west, each with the greatest angle found, how tall the obstruction is and how far away — so you can see what is driving the answer rather than just the verdict.
- Shade figures at the solstices and the equinox.Three figures, each counting shade at 09:00, 12:00 and 15:00, so “shaded all day in December” and “shaded only first thing” are distinguishable at a glance.
- Nine sun positions, printed. Altitude and azimuth for every moment sampled, so the geometry is checkable rather than trusted.
- Both survey vintages. This pack reads two surfaces — the bare-earth terrain model for ground levels and the first-return surface model for obstruction heights. They are different flights and can be different years, so both are stamped on every figure rather than one standing in for the other.
What it is not
This is a screening, not a BRE daylight and sunlight assessment, and three limits are worth knowing before you buy:
- It does not know where your windows are. BRE measures from the centre of the lowest affected window. Nobody has told this pack where the windows are, and guessing would be the whole assessment — so it measures from 2 m above ground at the middle of each elevation and says so on every figure. A window higher up will see a smaller angle than the number given.
- It measures what exists, not what you propose. The other half of a real assessment is what a new building would do to its neighbours, and that needs the proposed massing. Exceeding the angle is a trigger for further work, never a finding that daylight is unacceptable.
- The surface model is a snapshot, and it includes vegetation.A hedge surveyed at 6 m counts as a 6 m obstruction, and anything built, demolished, grown or felled since the survey is not in the figures.
Coverage
England only — the surface model is the Environment Agency’s. Where it has never been flown there is nothing to measure obstructions against, and the order refunds rather than delivering a guess.
Ordered against a site boundary or a dropped pin, which we snap to its registered land parcel. Buying a pack grants no subscription and changes nothing about your account.