MCS update to neighbouring properties.By Mywarmhome.co.uk / March 26, 2025 amendments to existing Permitted Development Rights (PDR) that apply in England to the following. 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.Read more.