New update to the Air Source Heat Pumps Professional Advice Note

Important new professional guidance on noise impacts tackling planning barriers to air source heat pump installations is launched

A new update to the Air Source Heat Pumps Professional Advice Note (2026) has been published after extensive consultation to support faster, lower-cost installation of air source heat pumps (ASHPs) while maintaining appropriate protection against noise impacts for neighbours against the MCS 020a standard.

Developed jointly by the Institute of Acoustics (IOA) and the Chartered Institute of Environmental Health (CIEH), the guidance provides clear, proportionate advice on acoustic assessment methods for planning applications where Permitted Development Rights do not apply. It is intended to remove unnecessary bureaucracy that can delay or deter ASHP installations, which are essential to achieving the UK’s net zero target by 2050.

The guidance introduces defined assessment pathways that sit between the existing MCS 020a method and full BS 4142 assessment, which is often a requirement of Local Authorities. The guidance includes example conditions to assist Local Authorities with a different approach.  For most installations, simple compliance routes are set out, including desktop calculations demonstrating compliance with a 37 dB(A) sound level criterion. More detailed assessments are reserved for exceptional or sensitive situations, such as tranquil locations or developments with multiple units and potential cumulative impact.

Evidence and current knowledge of the working groups involved has underpinning the approach taken, and as it develops further updated to the guidance are expected. Currently the 37 dB(A) threshold is already considered to account for tonal characteristics, aligns with established European and Scottish practice, and has not led to increased noise complaints to date. The guidance also clarifies appropriate selection of manufacturer sound power data and where the grey areas in knowledge exist. It also highlights good acoustic design principles, including careful siting, vibration control, and avoidance of unnecessary enclosures.

The note advises that planning conditions related to noise will rarely be required and, where justified, should be simple, precise and proportionate.

This new advice replaces earlier guidance and has been produced by a joint working group of acousticians and environmental health professionals, with input from the Association of Noise Consultants. It is intended to provide consistent, evidence-based decision-making for local planning authorities, environmental health practitioners and installers, supporting the rapid and responsible rollout of low-carbon heating across the UK.

You can find the full Air Source Heat Pumps Professional Advice Note (2026) note here