✓ Approved
Commercial plant
Location
Olney, Buckinghamshire
Planning authority
Milton Keynes City Council
Application
PLN/2025/2075
Decision
Approved with conditions, December 2025
Development
Two external air conditioning condensing units
Standards
BS 4142:2014+A1:2019, ISO 9613-2:2024
Even a small plant installation needs clear evidence when homes are nearby. This one needed to show two new condensers would not disturb nearby homes, day or night.
The Scheme
Two external air conditioning condensing units were proposed at a commercial building in Olney town centre, close to neighbouring homes.
The Noise Issue
Plant can run day and night, so the assessment had to compare predicted plant noise with the quietest background sound at the worst-affected residential façades.
What We Did
01
Ran an unattended 24-hour baseline survey to establish daytime and night-time background sound levels.
02
Used manufacturer sound data for the selected units.
03
Modelled sound propagation to the worst-affected façades to ISO 9613-2:2024.
04
Assessed the cumulative rating level in accordance with BS 4142:2014+A1:2019.
The Result
24 hours
Unattended baseline survey
2
Condensing units assessed together
Low
BS 4142 impact, no mitigation needed
Planning Outcome
The cumulative plant noise was assessed as a low impact under BS 4142, so no additional mitigation was required. Milton Keynes City Council approved the application with conditions in December 2025 (PLN/2025/2075).
Related services and guides
BS 4142 plant noise assessments →
Decision details are taken from the council's public planning register and can be checked by searching the application reference on the council's planning portal. Client and site details are kept confidential.
