Why UK house-builders will need to get familiar with heat pump technology

One of the most recurring phrases in the Government’s consultation on Part L of Schedule 1 to the Building Regulations is “heat pump” technology. Its proposed Future Homes Standard envisages a 31% reduction in CO2 emissions from new homes through improved insulation and more energy-efficient heating that avoids the use of fossil fuels including gas, LPG and oil.

It sees heat pumps playing a key role in this. It’s no surprise then that heat pump manufacturers featured heavily at the recent UK Construction Week exhibition and had TV architect George Clarke discussing them in the seminar programme.

What are heat pumps, who is using them now, and how can self-builders, developers and housing associations adopt them in new homes?

How do heat pumps work?

There are two main types of heat pumps:

Air Source Heat Pumps (ASHP) absorb heat from the outside air which is run through an evaporator and the resulting gas through a compressor to create heat. The heat can be used to heat water in radiators, underfloor heating or warm air convectors, and of course provide hot water.

They are attached to the outside of a home and look identical to external air-conditioning units. They need regular maintenance but, properly looked after, should last for 20 years.

Ground Source Heat Pumps (GSHP) use buried pipes to extract heat from the ground. This is passed through a heat exchanger into the heat pump, and can then heat radiators, underfloor heating, warm air heaters and provide hot water. There are also Water Source Heat Pumps (WSHP) but they require a nearby stream, river or lake to work.

These heat pump types also have an expected lifespan of 20 years.

GSHP systems are more expensive to install than ASHP as they require excavations for the buried pipework. On the plus side, they avoid the need for the external “air-conditioner-like” unit and attract higher tariffs than ASHP systems under the Renewable Heat Incentive (RHI) scheme (see below).

What are the benefits of using heat pumps?

Apart from obviously not using fossil-fuels, the power needed to run these systems is much reduced, so reducing household bills and lifetime CO2 emissions from the home.

Social housing providers can use the technology to help reduce fuel poverty, especially if homes are built using modern methods of construction and benefit from improved thermal insulation.

For self-builders and renovators (retrofit), homeowners can earn income through the RHI scheme, which offers a rebate on the “renewable” heat the system produces. The aim of RHI is to provide incentive for people to take on the more significant capital costs of installing a heat pump rather than a traditional fossil-fuel based system.

RHI is only offered through Microgeneration Certification Scheme (MCS) compliant systems and does not apply for new-build homes from developers.

Who is using heat pumps now?

The latest Building Services Research and Information Association (BSRIA) research indicates that around 22,000 heat pumps were installed in the UK in 2017, an increase of 18% in volume compared to the previous year. This, however, contrasted against a continual market decline in the previous five years.

By 2020, it is expected that there will be 500,000 heat pumps in the UK. This is still a tiny 1% of the heating systems used in the UK (85% of all heating relies on gas boilers, and 1.5 million gas boilers are still being installed every year). ASHP systems are considerably more popular than the more expensive GSHP alternative.

Housing associations and local authorities are more likely to adopt heat pump technology. Shared GSHP systems – where the expensive ground installation heats multiple homes – can earn councils and associations revenue via the Non-Domestic RHI scheme. In Enfield, for example, the council has installed GSHP systems in 400 flats linked to a shared, large scale ground loop. Through RHI, Enfield Council will receive payments from the system for 20 years, while helping to reduce the energy bills of its residents.

What will it take for heat pumps to be widely adopted in the UK?

The UK remains Europe’s biggest market for gas boilers, but not for much longer perhaps. With the Government’s Future Homes Standard set to be backed by new regulation by 2025 and a commitment to net zero UK carbon emissions by 2050, housebuilders need to find alternative, more energy efficient methods of heating and powering homes.

Speaking at UK Construction Week, George Clarke said, “We’ve had an industrial revolution. Now we need an ecological revolution.” It may sound like a well-rehearsed TV soundbite, but he admitted also the higher costs were an issue, on top of construction costs rising and the availability of land not getting any easier. “It’s understandable that sustainability is down the pecking order,” he added.

Government too recognises the cost barrier, but equally the lack of an established market for heat pump in technology in the UK, with few suppliers, limited knowledge and skilled installers.

So how can developers take up the heat pump challenge? In its consultation of Part L, the Government makes a statement and asks the question – and the replies may shape the answer:

We think heat pumps and heat networks should typically be used to deliver the low carbon heating requirement of the Future Homes Standard. What are your views on this?


Please Note: Every care was taken to ensure the information in this article was correct at the time of publication. Any written guidance provided does not replace the reader’s professional judgement and any construction project should comply with the relevant Building Regulations or applicable technical standards. However, for the most up to date LABC Warranty technical guidance please refer to your Risk Management Surveyor and the latest version of the LABC Warranty technical manual.

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