Martyn Bridges, Director of Technical Communications and Product Management at Worcester Bosch, discusses the low carbon heating systems suitable for new build properties.
The government’s recent announcement regarding gas boilers earlier this year sparked considerable confusion around how homes will be heated from 2025 onwards, as many believed that gas boilers were to be banned entirely. What the announcement really means is that gas boilers are unlikely to be installed into new build properties from 2025 onwards as the house won’t be able to meet the carbon reduction targets they will have to meet. So, in reality, they will remain within most homes across the country.
The interesting point to explore is which alternate technologies we might expect to dominate the new build landscape from 2025 in order to meet new decarbonisation targets. What are the technologies and how will the shift from gas boilers impact the homeowner and installer alike?
Gas boilers remain
Today, most new build properties have a gas fired boiler fitted. These are predominantly combi-boilers and the use of them is widespread. Over 17 million homes have a combi-boiler installed and many new builds have something similar. The switch will be enforced to achieve the latest decarbonisation target of a 75 – 80 per cent reduction in domestic carbon emissions in new builds from 2025 onwards, when compared to the 2013 equivalent Building Regulations.
The combi-boilers many of us have in our homes will be unable to achieve this target, meaning that new builds and the majority of individual properties will require an air source heat pump, or potentially a ground-source equivalent, fitted within the property. Consequently, the safe-saving abilities of the combi-boiler will be stretched from 2025 onwards, as more space will be required to house the lower carbon alternatives.
Greater expense, greater space
Such requirements mean a shift in costs and logistics for home heating. From a builder’s perspective, the cost of an air to water heat pump system is at least double that of a combi-boiler. On top of this, the homeowner will need to fit larger radiators, larger pipe work diameters, along with an increased amount of underfloor heating pipework compared to the equivalent amount of a gas fired boiler.
Moreover, for heat pump technology, a greater amount of space would have to be dedicated to the heating system. While this may sound negative on the surface, such space requirements make heat pumps ideal for new builds which, unlike existing homes, would be able to be designed around the new space requirements.
Moreover, even the most brand-new properties with a combi-boilers installed do not have a requirement for a hot water storage cylinder, and this will have to change if we are to meet government targets. Builders will have to provide a space, perhaps an airing cupboard for example, for the hot water storage cylinder to be installed along with the necessary hydraulic connections necessary for a heat pump to operate.
Aside from the heating industry, I expect that new build properties will be required to provide storage space for electrical batteries alongside space for the heating system. In the coming years we are likely to see an increased uptake in Solar PV fitted onto rooves. To optimise their performance, battery storage would be another serious consideration for new builds from 2025 onwards, which will be required to meet the 75 – 80 per cent reduction target.
Beyond this, we may see additional technologies introduced into new builds too.
For example, rather than boiler fed radiators like we have today, we are very likely to see perhaps fan assisted radiators or at least larger surface free radiators more suited to heatpumps. We could also see mechanical ventilation, heat recovery systems, and even waste water recovery systems becoming more and more common in homes across the country.
Costly, complex, but crucial
These changes and adaptations will surely mean a serious wave of upskilling for engineers, builders, and installers. How these changes are effectively demonstrated to the homeowner will also pose a challenge, as we enter this period of widespread change.
Despite this complexity and inevitable expense, it is undoubtedly a good thing that the industry and country are moving towards making new build properties a nearly zero carbon situation from the mid-2020s onwards. Yes, this comes with cost and complexity, but it is crucial to the beginning of how all homes will be built for the better in our future.
For further information on Worcester Bosch visit https://www.worcester-bosch.co.uk/