Non-residential acoustic regulations

School design

Relevant regulations and guidelines

Section E4 of Part E of the Building Regulations covers the requirements for control of sound insulation, reverberation and indoor ambient noise levels for new school buildings.

Section 1 of Building Bulletin 93: Acoustic design of schools – a design guide: 2003, DfES (BB93) sets the performance standards for the acoustics of new school buildings.

Where the performance values for sound insulation, reverberation time and indoor ambient noise levels given in Section 1 of BB 93 are followed, the Building Regulations Part E4 will be satisfied.

Building Bulletin 93

Requirements for indoor ambient noise levels are set out in Table 27: BB 93 Table 1.1. which is shown on the opposite page. Using the Activity noise and Noise tolerance for the spaces on each side of a partition, it is possible to use Table 26: BB 93 1.2 to determine the required sound performance of the partition.

The sound performance in Table 26 is given in terms of DnT (Tmf, max),w, which effectively means that it is an average for the complete partition, including any glazed panels or doors.

In practice, the Building Regulations and Building Bulletin 93 should be referred to as definitive guidance.

**Table 26: BB 93 Table 1.2: Performance standards for airborne sound insulation between spaces – minimum weighted BB 93 standardised level difference, D_{nT (Tmf,max),w} (dB)**
Minimum D_nT _(Tmf,max),w (dB)		Activity noise in source room (see Table 1.1)
		Low	Average	High	Very high
Noise tolerance in receiving room (see Table 1.1)	High	30	35	45	55
	Medium	35	40	50	55
	Low	40	45	55	55
	Very low	45	50	55	60
1. Each value in the table is the minimum required to comply with the Building Regulations. A value of 55 D_{nT (Tmf,max),w} dBbetween two music practice rooms will not mean that the music will be inaudible between the rooms. In many cases, particularly if brass or percussion instruments are played, a higher value is desirable. 2. Where values greater than 55 D_{nT (Tmf,max),w} dB are required it is advisable to separate the rooms using acoustically less sensitive areas such as corridors and storerooms. Where this is not possible, higher performance constructions are likely to be required and specialist advice should be sought. It is also important to ensure that high-use corridors are not themselves a significant source of noise. 3. It is recommended that music rooms should not be placed adjacent to design and technology spaces or art rooms. 4. These values of D_{nT (Tmf,max),w} include the effect of glazing, doors and other weaknesses in the partition. In general, normal (non-acoustic) doors provide much less sound insulation than the surrounding walls and reduce the overall D_{nT (Tmf,max),w} of the wall considerably, particularly for values above 35 D_{nT (Tmf,max),w} dB. Therefore, doors should not generally be installed in partitions between rooms requiring values above 35 D_{nT (Tmf,max),w} dB unless acoustic doors, door lobbies, or double doors with an airspace are used. This is not normally a problem as rooms are usually accessed via corridors or circulation spaces so that there are at least two doors between noise-sensitive rooms.

**Table 27: BB 93 Table 1.1 Performance standards for indoor ambient noise levels**
Type of room	Room classification for the purpose of airborne sound insulation in table 2		Upper limit for the indoor ambient noise level
	Activity noise (Source room)	Noise tolerance (Receiving room)	dB LAeq,30min
Nursery School
Playroom	High	Low	35¹
Quiet Room	Low	Low	35¹
Primary School
Classroom, classbase, general teaching area, small group room	Average	Low	35¹
Secondary School
Classroom, general teaching area, seminar room, tutorial room, language laboratory	Average	Low	35¹
Open Plan²
Teaching area	Average	Low	40¹
Resource area	Average	Low	40¹
Music
Music classroom	Very high	Low	35¹
Small practice/group room	Very high	Low	35¹
Ensemble room	Very high	Very low	30¹
Performance/recital room	Very high	Very low	30¹
Recording studio³	Very high	Very low	30¹
Control room for recording	High	Low	35¹
Lecture Rooms
Small (<50 people)	Average	Low	35¹
Large (>50 people)	Average	Very low	30¹
Classroom designed specifically for use by hearing impaired pupils (inc. speech therapy rooms)	Average	Very low	30¹
Study room (individual study, withdrawal, remedial work, teacher preparation)	Low	Low	35¹
Library
Quiet study area	Low	Low	35¹
Resource area	Average	Medium	40
Science Laboratory	Average	Medium	40
Drama Studio	High	Very low	30¹
Design & Technology
Metalwork, Woodword, CADCAM areas	High	High	40
Electronics, control, textiles, graphics, design areas	Average	Medium	40
Art rooms	Average	Medium	40
Assembly hall⁴, multi-purpose hall⁴ (drama, PE, audio-visual presentations, assembly, occasional music)	High	Low	35¹
Audio-visual, video conference rooms	Average	Low	35¹
Atria, circulation spaces	Average	Medium	45
Indoor sports hall	High	Medium	40
Dance studio	High	Medium	40
Gymnasium	High	Medium	40
Swimming pool	High	High	50
Interviewing/counselling, medical room			35¹
Dining rooms	High	High	45
Ancilliary spaces⁵
Kitchens	High	High	50
Offices, Staff Rooms	Average	Medium	40
Corridors, stair wells	Average to high	High	45
Coats, changing areas	High	High	45
Toilets	High	High	50
¹ Research indicates that teaching can be disrupted by individual noisy events such as aircraft flyovers, even where the noise level is below the limits in Table 1.1. For rooms identified in Table 1.1 having limits of 35 dB or less the noise level should not regularly exceed 55 dB LA1,30min. ² Acoustic considerations of open plan areas are complex. To ensure the intelligibility of speech, a computer prediction model should be used to calculate the Speech Transmission Index (STI) in the open plan space, using the overall noise level as the background noise level. The overall noise level is a combination of (a) the indoor ambient noise level, (b) all activities in the open plan space (including teaching and study), and (c) transmitted noise from adjacent spaces. The calculated value of STI should be between 0.60 and 1.00, which gives an STI rating of either ÔgoodÕ or ÔexcellentÕ. Table 1.6 gives the performance standard for speech intelligibility in open plan spaces. ³ Studios require specialised acoustic environments and the noise limits for these will vary with size, intended use and type of room. In some cases noise limits below 30 dB LAeq may be required, and separate limits for different types of noise may be appropriate. Specialist advice should be sought. ⁴ Halls are often multi-functional spaces (especially in primary schools) that can be used for dining, PE, drama, music, assembly, and performing plays and concerts. In such multi-functional spaces the designer should design to the lowest indoor ambient noise level for which the space is likely to be used. For large halls used for formal drama and music performance lower noise levels than those in Table 1.1 are preferable, and levels of 25 dB LAeq,30min may be appropriate. In these cases specialist advice should be sought. ⁵ The inclusion of schools within Part E of Schedule 1 to the Building Regulations 2000 (as amended by SI 2002/2871) applies to teaching and learning spaces and is not intended to cover administration and ancillary spaces. For these areas the performance standards are for guidance only.