Do heat pumps work in old Cornish houses?

Yes, provided the emitters are sized for low flow temperature and basic fabric work has been done. The mild Cornish winter is favourable, the solid walls are the part that needs attention.

Do I need planning permission for an air source heat pump?

Frequently not, where the installation meets the permitted development conditions, but listed buildings, Conservation Areas, protected landscapes and flats commonly need consent. Check the specific position for your property.

Will I have to replace every radiator?

Not always. A heat loss calculation identifies which rooms are short, and often a proportion of existing radiators are already adequate for a lower flow temperature.

Is underfloor heating necessary?

No, but it suits low flow temperatures well, and where a floor is being rebuilt anyway it is usually the sensible moment to install it.

Services · Cornwall

Heat pumps in Cornish homes, why the fabric decides whether the system feels good

Cornwall has a mild winter, a lot of off gas housing and a lot of solid walls, which makes it both a good place for heat pumps and an easy place to install one badly. A heat pump delivers a large volume of gently warm water rather than a small volume of very hot water, so it changes how a house is heated. Where that difference is designed for, the result is comfortable and cheap to run. Where it is bolted onto an unchanged system, the result is a disappointed owner and an expensive electricity bill.

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Flow temperature is the whole story

Efficiency falls as flow temperature rises, so a system designed to run at a low flow temperature performs dramatically better than one running hot to compensate for undersized emitters. Achieving that means the emitters and the fabric have to do more of the work, which is why heat pump projects are really fabric and distribution projects with a heat pump attached at the end.

A room by room heat loss calculation, not a rule of thumb sizing
Larger radiators or underfloor heating sized for low flow temperature
Pipework capable of carrying the required flow rate without noise
A hot water cylinder with a coil suited to heat pump temperatures
Sensible controls, since these systems reward steady running over on and off boosting

Fabric first, and what that means in a Cornish cottage

Loft insulation, draught sealing and floor insulation usually deliver more comfort per pound than any plant upgrade, and they lower the required output so the unit can be smaller. In solid walled buildings the fabric work has to be vapour open so the wall keeps drying, and it should follow the same principles set out in our guidance on retrofit and on cob and stone. Sequencing matters: insulate first, then size the system to the improved house.

Siting, noise and planning

External units need airflow, a stable base, a condensate route and enough separation from boundaries and windows to keep noise acceptable. Many installations fall within permitted development subject to conditions, but protected landscapes, Conservation Areas, listed buildings and flats change that. On a Cornish coastal site the corrosion question is real, so location out of direct salt spray and a maintenance regime both matter.

Coordinating with the building work

The cheapest time to install underfloor heating, upsize pipework and run the electrical supply is while floors are up and walls are open. Deciding on the heating strategy during design, rather than after the plaster is on, avoids paying twice. Where a project is already going through building regulations, the heating and ventilation strategy can be developed within the same package.

Frequently asked

Straight answers.

Do heat pumps work in old Cornish houses?: Yes, provided the emitters are sized for low flow temperature and basic fabric work has been done. The mild Cornish winter is favourable, the solid walls are the part that needs attention.
Do I need planning permission for an air source heat pump?: Frequently not, where the installation meets the permitted development conditions, but listed buildings, Conservation Areas, protected landscapes and flats commonly need consent. Check the specific position for your property.
Will I have to replace every radiator?: Not always. A heat loss calculation identifies which rooms are short, and often a proportion of existing radiators are already adequate for a lower flow temperature.
Is underfloor heating necessary?: No, but it suits low flow temperatures well, and where a floor is being rebuilt anyway it is usually the sensible moment to install it.

Planning a heating upgrade alongside building work?

Tell us about the property and what you are changing. We will show you where the heating decisions belong in the programme.

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