What homes are suitable for an ASHP?​

First, you’ll need some outdoor space. Heat pumps require clearances on all sides to maintain airflow and allow for maintenance. As a general guide, you’ll need a space about 1.7m wide (the width of a standard bath) by 1.3m deep. Also, newer units use a flammable refrigerant, so they can’t be installed next to doors.

Now, what about insulation? There’s a common myth that heat pumps only work in well-insulated homes, but that’s not true! They’re successfully heating all kinds of properties—from high-performance passive houses to single-glazed homes. Inside tip: Your home’s EPC gives a great snapshot of past upgrades, build date, and insulation levels.

Inside your home, you’ll need space for a hot water cylinder, traditionally in an airing cupboard. You might also need larger radiators because heat pumps run at lower temperatures than gas or oil boilers, meaning they need a bigger surface area to provide the same warmth. If you have underfloor heating, that’s ideal.

There may also be some pipework upgrades, as heat pumps need about four times the flow rate of a modern gas boiler.

Additionally, your electric and water supply will be checked to make sure everything will be safe and work well.

Finally, if you have a large and/or poorly insulated home, you might need more than one heat pump unit, known as a cascade system, or an additional backup heater. Most single units max out at around 13kW, which is enough for most properties.

We know this is a lot to consider, but a quality installer will take care of all these details to make sure your system is right for your home!