Data · Sourced
UK reverberation-time targets by space
The reverberation-time (RT / Tmf) figures UK standards set for different rooms — every target quoted from, and linked to, its governing standard. If a standard does not set a number, we say so rather than invent one.
There is no single UK reverberation-time figure that fits every room: the right target depends on what the space is used for. This table gathers the reverberation-time (RT) targets that named UK standards and guidance actually set, space by space, with each figure traceable to its published source. Where a standard states a limit or a range, it is reproduced here exactly as that standard gives it — never rounded, averaged or invented. Where UK guidance sets no reverberation-time number for a space (for example ordinary homes and general offices), the row says so plainly rather than supplying a figure the standard does not contain. Every target below concerns reverberation inside a room — the build-up of echo and lingering sound — and not sound insulation between rooms, which is a separate matter.
| Space | Reverberation target | Standard | Notes | Source |
|---|---|---|---|---|
| Nursery and primary-school teaching rooms (classroom, general teaching area, small group room, SEN calming room) | Tmf ≤ 0.6 s (new build) | BB93 (Building Bulletin 93), England | Tmf is the arithmetic average of the reverberation times in the 500 Hz, 1 kHz and 2 kHz octave bands. This is the new-build limit; the refurbishment limit is ≤ 0.8 s. | Department for Education, Building Bulletin 93: Acoustic design of schools — performance standards (February 2015), Table 6 |
| Secondary-school teaching rooms (classroom, general teaching area, seminar/tutorial room, science laboratory, design & technology) | Tmf ≤ 0.8 s (new build) | BB93 (Building Bulletin 93), England | Mid-frequency (500 Hz–2 kHz) average. New-build limit; the refurbishment limit is ≤ 1.0 s. Individual study rooms share the same 0.8 s limit. | Department for Education, Building Bulletin 93: Acoustic design of schools — performance standards (February 2015), Table 6 |
| Teaching space designed specifically for pupils with special hearing or communication needs | T ≤ 0.4 s averaged over the 125 Hz–4 kHz octave bands, and T ≤ 0.6 s in every octave band across that range (new build) | BB93 (Building Bulletin 93), England | The tightest school target, because these rooms demand the clearest possible speech. Stated exactly as BB93 gives it, including the per-band limit. | Department for Education, Building Bulletin 93: Acoustic design of schools — performance standards (February 2015), Table 6 |
| Lecture rooms in schools and colleges | Tmf ≤ 0.8 s for rooms holding fewer than 50 people; Tmf ≤ 1.0 s for rooms holding more than 50 people (new build) | BB93 (Building Bulletin 93), England | Mid-frequency (500 Hz–2 kHz) average; new-build limits. Larger audiences are allowed a slightly longer reverberation time. | Department for Education, Building Bulletin 93: Acoustic design of schools — performance standards (February 2015), Table 6 |
| School assembly hall or multi-purpose hall (assembly, drama, PE, presentations, occasional music) | Tmf 0.8–1.2 s (new build) | BB93 (Building Bulletin 93), England | Given as a range because the hall serves several competing uses. The refurbishment range is 0.8–1.5 s. | Department for Education, Building Bulletin 93: Acoustic design of schools — performance standards (February 2015), Table 6 |
| Indoor sports hall and swimming pool (schools) | Tmf ≤ 1.5–2.0 s (new build), depending on the size of the space | BB93 (Building Bulletin 93), England | Larger volumes sit toward the upper end of the range; the refurbishment limit is ≤ 2.0 s. See BB93 section 1.6 for how size is taken into account. | Department for Education, Building Bulletin 93: Acoustic design of schools — performance standards (February 2015), Table 6 and section 1.6 |
| Homes and flats (individual dwelling rooms such as living rooms and bedrooms) | No reverberation-time limit is set for rooms inside dwellings. | Approved Document E / BS 8233:2014 | The Building Regulations (Approved Document E) set no room reverberation-time figure for dwellings. For the common corridors, stairwells and entrance halls of buildings containing flats, Requirement E3 instead calls for added acoustic absorption — specified as an absorption area, not a reverberation-time value. BS 8233 guides indoor ambient noise levels for homes, again not reverberation time. | Ministry of Housing, Communities & Local Government, The Building Regulations 2010 — Approved Document E: Resistance to the passage of sound (2003 edition, as amended) |
| Offices and open-plan workplaces | No fixed reverberation-time figure is set by these standards. | BS 8233:2014 / ISO 3382-3:2022 | Open-plan office acoustics are judged by ISO 3382-3 parameters — the spatial decay rate of speech (D2,S), the A-weighted speech level at 4 m and the resulting distraction distance — rather than a single reverberation-time target. BS 8233 sets indoor ambient noise levels, not reverberation time. Absorption is still used to shorten reverberation and reduce distraction, but performance is assessed against those parameters, not a stated RT number. | ISO 3382-3:2022, Acoustics — Measurement of room acoustic parameters — Part 3: Open plan offices, International Organization for Standardization |
| Hospitals and healthcare rooms (wards, patient bedrooms, consulting and treatment rooms) | No single reverberation-time figure is fixed; the reverberation-time criterion is agreed for each space. | HTM 08-01: Acoustics (NHS England) | Where speech intelligibility matters, HTM 08-01 calls for absorbent treatment equivalent to at least a Class C absorber over 80% of the floor area, in addition to the absorption of the normal building materials (less area is needed if a Class A or B material is used), and states that a reverberation-time criterion should be agreed for the specific use of the space. The 0.8 s that appears elsewhere in HTM 08-01 is the reference reverberation time used in its sound-insulation calculation, not an in-room reverberation target. | Department of Health / NHS England, Health Technical Memorandum 08-01: Acoustics |
Read this before you specify. These figures are starting points, not guarantees. The right reverberation time for any specific room depends on its use, its volume and its finishes, and the binding target for a real project is the one set and modelled by the project's acoustician against the relevant standard — not a value read from a table. Reverberation control is an in-room matter: it shortens the echo and lingering sound within a space so speech stays clear. It is a separate discipline from sound insulation, which stops noise passing between rooms and depends on the mass and construction of walls, floors and doors. No panel, ceiling or product meets any of these targets on its own; compliance is a property of the finished, modelled room.