Illustrative worked example. This is a realistic brief run through Echo using the same method a real report uses — not an account of a named past client. See every case study for more, including which of these are real, permissioned projects as they're added.
The brief
A secondary school's sports hall was on the capital works list for a different reason — leaking rooflights — and the PE department used the opportunity to flag what staff had been raising for two years: instructions and safety calls were being lost during PE lessons, and whole-school assembly in the hall meant half the room straining to hear.
Secondary school sports hall, four courts
36 × 20 × 8 m, about 5,760 m³ — sprung timber floor, painted blockwork walls, profiled metal deck roof with rooflights.
A hard floor built for sport, blockwork on every wall and a metal roof deck put the hall's reverberation time well above two seconds — fine for nobody in particular, and the direct cause of both the PE-instruction and assembly complaints.
The standard, and the target
This is a school hall, so BB93 is the standard that applies: it sets reverberation limits for school sports halls that depend on the size of the hall, so check the figure for your own hall's volume. Sport England's design guidance covers community sports halls and is a range rather than a pass/fail limit. Because this hall also takes evening five-a-side bookings, the brief was to get well clear of the two-second-plus starting point and move toward the school standard, without treating the hall like a classroom. Check the BB93 figure for your own hall's volume.
The constraint
The council's capital budget for this job was fixed by the wider rooflight works and couldn't flex, and the school's own ball-sport safety policy ruled out anything fixed to the walls below 2.5 metres, where a stray ball could reach it.
The decision
The fix stayed at height and within budget: ceiling rafts hung in the bays between the rooflights (so daylight wasn't blocked), high-level wall absorption above the 2.5-metre ball-strike line on the two longer walls, and a heavy curtain divider track was costed as a reserve option for splitting the hall during exams but not taken up this round.
Every route considered, vendor-neutral — we don't sell any of it.
- Ceiling rafts, hung between rooflightsabout 260 m²
The main move — positioned to leave every rooflight clear.
- High-level wall panels, above 2.5 mabout 140 m²
Kept clear of the ball-strike zone per the school's own safety policy.
- Curtain divider track (reserve, not taken up)18 m span
Priced for splitting the hall during exam season — parked for a future budget round, not part of this fix.
The outcome
The model predicts rafts and high-level panels would bring the hall from over two seconds to roughly 1.3, within the range where PE instructions and assembly announcements should stay clearer, while keeping it lively enough for the evening five-a-side bookings the hall relies on for income. This is a design-stage prediction for an illustrative room, not a measured result.
Indicative figures for this example, from the same method a real report uses. Not a measured survey and not a compliance certificate — where one is required, that's a survey to BS EN ISO 3382-2.
Now do it for your room.
Four questions, about a minute. Free to see whether you have a problem.
Check my room →Questions people ask
Why not treat the whole wall, not just above 2.5 metres?
The school's ball-sport safety policy for this hall rules out anything below that line — a real constraint, not a cost-saving guess, so the fix had to find enough absorption from the ceiling and the walls above it alone.
Is 1.3 seconds the right number for every sports hall?
No — it depends on the hall's use and size. A school hall is judged against BB93; a community hall is judged against Sport England's guidance, which is a range because a hall used only for exams needs something closer to a classroom and one used only for five-a-side needs to stay livelier. This hall does three different jobs, so the target sits towards the middle of what the standard allows.
Does this count as compliance with the guidance?
No — this is an indicative design-stage prediction, not a measured survey. Where BB93 compliance has to be demonstrated, that is a measured survey to BS EN ISO 3382-2; Sport England's guidance, for community use, is guidance rather than a pass/fail test.