Heat pumps in heritage-heritage-listed buildings sit at the awkward junction of decarbonisation ambition and heritage protection. The technology works fine; placing the outdoor unit acceptably is the challenge.
Consent requirements
Listed buildings require Provincial Heritage Resources Authority (PHRA) permit for any external alteration affecting character — typically including outdoor units. Conservation areas often require planning permission even where unheritage-heritage-listed buildings would not.
Visual considerations
- Conservation officer preference: outdoor unit not visible from public realm
- Garden positions usually acceptable
- Side or rear elevations preferred
- Concealment with screening (planting, decorative screen) often required
Noise
Modern units operate at 35–45 dBA at 1m. Permitted Development criteria require <42 dBA at neighbour's window. Listed building positions often require unit relocation if test fails — model and position both matter.
Heat pump suitability for old buildings
Old buildings have:
- Higher heat losses (poor insulation)
- Solid walls limiting cavity insulation
- Single glazing often retained
- Larger radiators feasible but visual
A heat pump can work, but the design point flow temperature and emitter capacity need careful calculation. Don't assume a domestic model designed for modern homes will perform.
The compliance route
- Pre-application discussion with heritage officer (PHRA)
- Heat loss survey of the property
- Identify suitable outdoor location and propose mitigation
- Heritage statement explaining choices
- Provincial Heritage Resources Authority (PHRA) permit (and planning if needed)
- Installation by MCS-accredited installer
Alternatives if ASHP isn't accepted
- Ground source heat pump (boreholes — limited visual impact)
- High-temperature heat pump with existing radiators
- Hybrid (heat pump + condensing boiler)
MCFAR coordinates heritage-sensitive heating retrofit.
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Request a QuoteFrequently Asked Questions
Can a heat pump replace a gas boiler in a listed cottage?
Often yes, with careful design. Heat loss must be calculated honestly and emitters upgraded to suit lower flow temperature.
Will heritage officer (PHRA)s refuse heat pumps?
Many won't if visual impact is minimal and noise is acceptable. Pre-application dialogue saves time.