This update was driven by the government’s consultation and subsequent announcement on amendments to existing Permitted Development Rights (PDR) that apply in England to:
- Remove the 1m boundary rule, enabling heat pumps to be installed within 1m of the property boundary.
- Increase the size limit of the heat pump for dwelling houses from 0.6m3 to 1.5m3.
- Double the number of heat pumps permitted, from one to two for detached dwelling houses.
- Support the rollout of air-to-air heat pumps that can also provide a cooling function.
The MCS 020 Standard is now divided into two parts: one for air source heat pumps and another for small wind turbines (there are no changes to the requirements for small wind turbines).
This update aims to simplify compliance and improve clarity for installers.
Compliance with this update is mandatory for installers seeking to install air source heat pumps under Permitted Development from the date of implementation – 20 September 2025.