Isaac Occhipinti, Head of External Affairs at the Hot Water Association, discusses some of the incoming changes likely to be brought about by Part L and the Future Homes Standard.
For the last 10 years or so, combi boilers have taken a very high market share of newbuild properties. Much of this is driven by consumers who have become acclimatised to them. Another reason for the mass-market share is that additional space isn’t required for a hot water cylinder.
However, a lot of it is down to the hot water efficiency and how it affects the SAP rating of the dwellings. Put simply, certain combi boilers have a very high SAP rating for hot water, therefore allowing the housebuilder to achieve the target emission rating without so much fabric insulation. Consequently, we sometimes see combi boilers specified in multiple bathroom properties where a combi boiler realistically isn’t always the best choice.
Yet, there is a new light at the end of the tunnel for hot water storage in newbuild properties with the announcement of Part L and the Future Homes Standard. But is it worth housebuilders leapfrogging Part L 2020 and just developing with the Future Homes Standard in mind?
By Q3 of 2020, Part L will have been published which still allows the use of a gas boiler. There are two options on the table for housebuilders, a 20% reduction in CO2, or a 31% reduction, based on a 2013 regulation house. There are two notional buildings used which form the ultimate target emission that builders must exceed, and both at present use a gas-fired boiler along with a wastewater recovery system and/or solar PV to reach the higher 31% efficiency saving.
The Future Homes Standard, on the other hand, will implement a 75% reduction in energy consumption in 2025 over a 2013 regulation compliant house, something that currently won’t be achievable with a boiler. This is only possible with a renewable heat source, such as a heat pump. The positive is that this will help increase the use of hot water storage among newbuild homes.
That is a big jump within five years and, after consulting with some national housebuilders, it seems some are understandably starting to think it might be worth skipping next year’s Part L and instead start fitting boiler alternatives such as ground or air source heat pumps.
One of the things not apparent in either Part L or the Future Homes policy was the requirement for a dedicated storage space. Plans were outlined in the original discussions regarding changes to Part L for the builder to dedicate a roughly 2.5x2.5m compartment for either hot water storage or electric battery storage. That wasn’t noticeable in either policy and, of course, if that isn’t put in place, then there will be a problem as there won’t be any space beside the cylinder. So, that needs to be introduced or re-introduced, particularly in smaller properties where it may not be ideal for the homeowner if you end up with a cumbersome hot water cylinder taking up precious space.
Either approach is acceptable, making changes that will work both in the short term and after 2025. However, if the decision is made to skip to the Future Homes Standard, you are denying the long term by not considering all possible low carbon heat sources. For example, in the future, boilers are likely to become low carbon – possibly even zero carbon if hydrogen gas gets mandated.
This does present a double-edged sword. On the one hand, if housebuilders opt for a ground or air source heat pump straight away, they are already at a low carbon solution. On the other, the homeowner will be stuck with that heat pump for the foreseeable future – particularly if they are purposely not connected to the gas grid. They would never have the opportunity to fit hydrogen, which could become the norm and more energy efficient in the long-term.
There are other factors to consider when planning for decarbonisation. Our sister organisation, the Heating and Hotwater Industry Council, is asking why we don’t look to connect the gas grid to newbuilds and existing off-gas properties.
This is a valid point as then the opportunity for hydrogen in the future wouldn’t be missed. Other parties are suggesting sticking with gas boilers as part of a hybrid system, where a ground or air source heat pump is supported by a boiler system. So, given a lack of consensus, it seems sensible to suggest not jumping ahead too much – a lot can change in five years.
In light of the ongoing coronavirus crisis, some of you may not be able to receive your copy of HVP magazine. If you’d like to change your delivery address, please contact our subscriptions department at firstname.lastname@example.org
Read a digital edition