MCS opened a consultation on 30 November 2023 on the MCS 020 planning standard, which governs how certified contractors establish whether an air source heat pump installation meets permitted development requirements1. The standard includes a calculation procedure to determine the noise limit1. Comments close at 12.00pm on Friday 26 January 20241.
MCS 020 was first issued in August 2011 and last updated in June 20191. MCS states that since then there have been significant improvements in heat pump technology, and that contractors and consumers have raised concerns that current Permitted Development Rights are a barrier to installation1. Planning is devolved, so conditions differ across the four devolved administrations, but all four require any air source heat pump to be compliant with MCS 0201.
The boundary distance rules differ by nation. Permitted Development Rights in Wales currently require air source heat pumps on domestic premises to be installed at least three metres from the site boundary; in England the rule is one metre1. MCS describes these requirements as a potential barrier to uptake, especially in a terraced housing context1.
"MCS is now consulting on MCS 020 and the proposed changes include improving the definition of a solid barrier, background noise level assumptions and updated guidance on location."
The consultation follows two independent reviews of air source heat pump noise emissions and planning regulations, commissioned separately by the UK Government Department for Energy Security and Net Zero (DESNZ) and the Welsh Government1. The DESNZ review, published in November 2023, recommended changes to Permitted Development Rights in England and to MCS 0201. At the Chancellor's Autumn Statement on 23 November 2023, it was announced that the UK Government will consult on changing Permitted Development Rights that apply in England, including removing the one metre boundary rule1. The Welsh Government anticipates a subsequent update to Permitted Development Rights for air source heat pumps in Wales1.
| Nation | Current boundary distance requirement |
|---|---|
| England | One metre from the site boundary1 |
| Wales | Three metres from the site boundary1 |
Why it matters for households
For a household considering an air source heat pump, the boundary distance rule can decide whether an installation is permitted development at all, or whether a planning application is needed. MCS notes that the current requirements are considered a potential barrier especially in terraced housing, where gardens and side returns are often narrow1. The MCS 020 noise assessment is the calculation that determines whether a proposed installation meets the noise limit under permitted development, so changes to the solid barrier definition and background noise assumptions affect how that calculation is carried out and what it returns. Because all four devolved administrations require compliance with MCS 020, the standard matters to households across the UK, while the boundary distance itself is set separately in each nation, as set out in the regulation and policy material and, for Wales, in energy and buildings policy in Wales. The practical effect for a home's energy independence turns on whether an installation can proceed without a planning application, and on what noise mitigation, such as a solid barrier, is needed to satisfy the standard.
What happens next
The consultation closes at 12.00pm on Friday 26 January 20241. The UK Government has announced it will consult on changing Permitted Development Rights in England, including removing the one metre boundary rule1. The Welsh Government anticipates a subsequent update to Permitted Development Rights for air source heat pumps in Wales1. No date has been reported for the outcome of the MCS consultation or for either government consultation.