Regulatory and notification issues on a heat pump replacement
A homeowner is replacing an old oil boiler with an 11 kW ASHP. The property is in a conservation area and the outdoor unit is proposed on a side wall facing a neighbour's kitchen window about 2.5 m away. The existing oil tank and boiler are to be removed. The homeowner has had no prior notification to the local authority and asks whether planning permission is needed. The installer is MCS-certified. The property has a 60 A supply and the heat pump needs 3.2 kW electrical input. The neighbour has already complained about noise.
1. Advise on planning, permitted development and noise for the outdoor unit location.
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Under permitted development for domestic heat pumps (England), there are conditions including: the unit must be sited to minimise impact, must comply with noise limits (typically no more than 42 dB(A) at 1 m from the neighbour's nearest window, assessed per the relevant guidance), and there are limits on the number of units and their size. A conservation area can remove some permitted development rights, so check with the local planning authority - do not assume PD applies. Being 2.5 m from a neighbour's kitchen window is a real noise risk; obtain the manufacturer's sound power level and calculate the level at the neighbour's window, allowing for directivity and any barriers.
If the calculated level exceeds the limit, or PD rights are withdrawn in the conservation area, a planning application is needed. Advise the homeowner to check with the LPA before installation and to keep records. The neighbour complaint makes this higher risk - consider a quieter location, acoustic enclosure, or anti-vibration mounts.
2. What electrical and notification/compliance steps are needed given the 60 A supply?
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The 60 A supply is a significant constraint. Heat pump at 3.2 kW ≈ 13.9 A; add general load and the supply may be marginal. Carry out a maximum-demand calculation and consider a supply upgrade with the DNO, or load management. The heat pump needs a dedicated circuit with correct protective device and RCD type per manufacturer instructions, and the installation must comply with BS 7671.
Notification/compliance: the work is notifiable electrical work - issue the appropriate certificate (EIC/minor works as applicable) and building regulations compliance. As an MCS installer, register the installation for the relevant scheme so the customer can access incentives, and provide the handover pack. Removing the oil boiler and tank requires appropriate waste transfer and decommissioning records; oil tank removal may need care if there is contamination. Advise the homeowner on all notifications before work starts.