What This Requirement Covers
Building services equipment (boilers, heat pumps, extract fans, water pumps, lifts, and waste pipes) can generate noise that transmits through the building structure and affects occupants. Approved Document E and BS 8233 (Guidance on sound insulation and noise reduction for buildings) provide guidance on controlling noise from building services.
Key Requirements
Internal Noise Criteria
BS 8233 recommends maximum internal noise levels
- Bedrooms (sleeping): 30 dB LAeq (night)
- Living rooms: 35 dB LAeq (day)
- Dining rooms: 40 dB LAeq (day)
- Kitchens: 45 dB LAeq (day)
- Offices: 35-40 dB LAeq
- Classrooms: 35 dB LAeq
Common Noise Sources
- Boilers and heat pumps: Fan noise and compressor vibration. Air source heat pumps are subject to a maximum of 42 dBA at the nearest neighbour's window (MCS 020 planning standard)
- Waste pipes and soil stacks: Water flow noise, particularly from WCs flushing above bedrooms
- Extract fans: Fan motor noise and ductwork resonance
- Lifts: Motor room noise and structural vibration from the lift shaft
- Water pipes: Flow noise, water hammer, and expansion noise
Control Measures
- Vibration isolation: Anti-vibration mountings for boilers, pumps, and fans; flexible connections between equipment and pipework
- Acoustic enclosures: Insulated enclosures around noisy equipment
- Duct lining or silencers: Acoustic duct lining or proprietary silencers to reduce noise transmission through ductwork
- Pipe isolation: Acoustic pipe wrapping and resilient pipe clips to prevent structure-borne noise from waste pipes
- Equipment selection: Specify equipment with low noise ratings from the outset
Practical Compliance Tips
- Check the noise output of all building services equipment at the specification stage; it is much easier to specify quiet equipment than to treat noisy equipment after installation
- Isolate all vibrating equipment from the structure using anti-vibration mounts
- Do not run waste pipes through walls or floors adjacent to bedrooms without acoustic isolation
- Insulate ductwork passing through occupied spaces to reduce both noise and thermal losses
- Test noise levels from building services during commissioning and before handover
- For air source heat pumps, carry out a noise assessment to demonstrate compliance with MCS 020 before installation
- Include building services noise criteria in the project specification and check compliance during construction