🏐BB93:2015 · United Kingdom

Gymnasium Acoustic Design to BB93:2015

Gymnasiums are among the most acoustically challenging room types due to their large volume, all-hard surfaces, and requirement for both physical activity and verbal instruction. Untreated gymnasiums commonly have RT60 of 3–5 seconds, rendering speech intelligibility for physical education instruction and emergency announcements unacceptable.

TL;DR

Under BB93:2015, a gymnasium of 1,500-2,500 m³ (typical dimensions 30m × 18m × 7m) requires an RT60 of ≤ 1.5s at 500-2000 Hz. Background noise must not exceed 40 dBA. A minimum STI of 0.45 is required for speech intelligibility. BB93:2015 requires RT60 <= 1.

RT60 Target

≤ 1.5s

Noise Limit

40 dBA

STI Minimum

≥ 0.45

Frequency Range

500-2000 Hz

Specific Requirements

Parameter	Target	Clause Reference	Notes
Reverberation Time (RT60)	≤ 1.5s	§1.4	500-2000 Hz (Tmf), Unoccupied
Background Noise Limit	≤ 45 LAeq,30min	Table 1.2	HVAC + building services, unoccupied
Frequency Range	500-2000 Hz	—	Octave bands for compliance assessment

Step-by-Step Compliance Calculation

1
Apply BB93 sports hall targets
RT60 <= 1.5s, indoor ambient noise <= 40 dBA, STI >= 0.45 per BB93 Table 1.2 for sports halls.
2
Design baffle system
Specify suspended baffles achieving required absorption. Coordinate with sports lighting and overhead equipment.
3
Assess adjacent space insulation
Design wall and floor assemblies to prevent sports noise intruding on adjacent classrooms per BB93 insulation targets.
4
Verify for DfE approval
Include sports hall acoustic compliance in the BB93 report for Department for Education approval.

Recommended Materials

Surface	Material Category	Min NRC	Coverage %
Ceiling	Suspended acoustic baffles	0.80	40%
Walls above 3m	Impact-resistant absorber	0.70	30%

Browse the full acoustic materials database for absorption coefficients and product specifications.

Common Failure Modes

⚠️PE teaching intelligibility

Teachers cannot be heard clearly during PE lessons when RT60 exceeds 2.0s, affecting both safety and learning outcomes.

⚠️Adjacent classroom noise

Ball impact and shouting in the gym transmits to adjacent classrooms through shared walls and structure.

Frequently Asked Questions

What RT60 does BB93:2015 require for a gymnasium?

BB93:2015 requires a reverberation time of ≤1.5s at 500-2000 Hz for gymnasium spaces. BB93:2015 requires RT60 <= 1.5s for school sports halls and gymnasium spaces. Indoor ambient noise must not exceed 40 dB LAeq,30min when the space is used for teaching. STI >= 0.45 is required for PA and teacher communication intelligibility during physical education activities.

What is the maximum background noise level for a gymnasium under BB93:2015?

BB93:2015 sets a maximum background noise level of 40 dBA for gymnasium spaces. This includes noise from HVAC systems, building services, and external intrusion, measured with the room unoccupied. Exceeding this limit degrades speech intelligibility and occupant comfort.

How much acoustic treatment does a gymnasium need to comply with BB93:2015?

A typical gymnasium (1,500-2,500 m³) requires Suspended acoustic baffles (NRC ≥0.8) covering 40% of the ceiling as the primary treatment. Additional wall absorption on 1 surface(s) is typically needed. Use the AcousPlan calculator with the pre-loaded dimensions (25m × 15m × 7m) to calculate the exact absorption deficit for your room.

Calculate BB93:2015 Compliance for Your Gymnasium

Pre-loaded with typical gymnasium dimensions (25m × 15m × 7m) and an RT60 target of 1.5s per BB93:2015. Enter your actual dimensions, select materials, and verify compliance instantly.

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