It is looking likely that the UK government is going to enforce its well heralded ban on the fitting of fossil fuelled boilers in new build properties in 2025 in an attempt to cut down the country’s CO2 emissions ahead of the 2050 nett zero emissions target.

 Quite surprisingly, domestic heating accounts for around 14% of total UK CO2 emissions, and on a more personal level, heating your home accounts for 65% of your total energy usage. That being the case, it would seem to be a good opportunity to cut both our own and the country’s greenhouse gas emissions, while at the same time adopting a more cost effective heating system.

Governments appear agreed that the preferred alternative heating system should be driven by a heat pump, either air source or ground source. These use relatively small amounts of electricity to run a compressor but do not contribute to CO2 emissions as they do not burn any fossil fuel.

Air source heat pumps extract heat energy stored naturally within the outside air and transfer for use indoors. Ground source heat pumps also take heat from outside, but as the name might suggest, they take their heat from the ground through a series of underground pipes rather than from the air. This heat is passed through a compressor and a heat exchanger and is passed into the property in the form of hot water.

Heat pumps deliver water at 65’C as opposed to the 75’C which an oil fired boiler does. 65’C is adequate for domestic hot water for shower and other washing needs in the home but falls a little short when delivering heat to the traditional radiators of a central heating system. As heat pumps won’t provide the instantaneous heat of traditional gas or oil heating and domestic hot water systems a possible rethink of the requirements for designing your heating may be required.

In an existing, traditionally built property, there will be a set of current water filled radiators which have been sized to radiate enough heat to keep the rooms of the house at a comfortable temperature. With heat pumps, these radiators would probably not heat the property to the same extent due to the lower operating temperature in comparison to an oil or gas fuelled boiler, so changing from a boiler to a heat pump may also mean that some homeowners may look to increase the size or number of their radiators to replicate the room temperatures of their previous heating system. It may be that in older properties it would be sufficient to replace old style radiators with modern, more efficient radiators of similar size.

As bedrooms do not have the same heat requirement as ground floor living accommodation there may not be the same pressure to increase the heating capacity on upper floors. This would leave the ground floor with the option having underfloor heating installed instead of larger radiators. Underfloor heating heats a room by inputting more heat at the slightly lower temperature but to a much larger area so achieves the same result overall.

The government introduced changes to the Building Regulations in June 2022, which saw new homes in England being required to produce around 30% less carbon emissions than under the previous regulations. The Future Homes and Buildings Standard set out by government in December 2021, will augment these Building Regulations to ensure that homes built from 2025 will produce 75-80% less carbon emissions than under previous building regulations, hence the proposed move away from fossil fuelled heating systems.

Developers should by now be thinking beyond the government edict and should not now be fitting gas boilers. It is less expensive to fit a heat pump driven heating system to a new build property than it is to retrofit one to an existing property, although it is still less expensive to fit a gas boiler when building a new property than a heat pump. Perhaps it may serve the community better if planners made heat pump systems a condition of planning permission.

New build properties from a heating perspective, are like painting on a blank canvass. The designer can specify the type of heating system to be used in the property - which should now be driven by a heat pump, bearing in mind the government ban on the fitting of fossil fuelled boilers in new build properties from 2025 - and can incorporate it into the design of the whole property. This takes away the need to compromise with the design and configuration of the heating system as is demanded in an existing property.

Installing a heat pump entails siting the unit outside, normally against the outer wall of the property, but unlike a combi-boiler, the system also needs a hot water storage tank, which can be difficult to accommodate in an existing property unless it is an older property which was pre combi-boiler and already had a hot water tank, often in the loft space. With a new build it is simple to design around this requirement and again the best place for a tank is in an accessible area of the loft.

Many new build homes are designed with underfloor heating in all ground floor areas and slightly over-sized radiators in upper floors, a configuration which suits the slightly lower temperature generated by heat pumps and the complete system can be designed around the property.

Installing a heat pump in most parts of the UK can be done as a permitted development with no need to apply for planning permission unless you live in a listed property, conservation area or a world heritage site, provided all the limits and conditions listed on “The Planning Portal”  are met. 

Anyone installing a heat pump to replace a fossil fuelled heating system in England or Wales will be able to benefit from the government’s The Boiler Upgrade Scheme (BUS) which will run from 2022 to 2028. The scheme only applies to systems installed by MCS certified installer and is installer led, which means that the installer will apply for the grant on your behalf and deduct the sum from your final invoice. The grant will be £5,000 for an Air Source Heat Pump and £6,000 for a Ground Source Heat Pump. The prices quoted by some of the larger energy suppliers include this grant.

If you are considering extending or altering your home, you may find some of these services useful: