Property owners are advised to take a holistic approach to the retrofit of their buildings to meet future needs and emissions targets, writes Andrew Mellor
As COP26 enters its final days and we hope for some big commitments from the world leaders, it seems appropriate to write about the Heat and Buildings Strategy which was published last month by the Department for Business, Energy and Industrial Strategy.
It is itself a big commitment from the government. It sets out the urgent need to reduce the heat energy requirements of buildings in the UK as well as to provide them with new low carbon heating systems.
Driven by the need to rapidly decarbonise our buildings and the legally binding targets of reducing the nation’s carbon dioxide emissions by 78% over 1990 levels by 2035 – and achieving net zero emissions by 2050 – the strategy sets out the government’s plans for achieving such reductions.
It is aimed primarily at existing buildings because they have the greatest impact in terms of operational carbon emissions and it covers domestic residential, public and non-domestic uses. New buildings are considered in the context of the proposed Future Homes Standard and Future Buildings Standard as well as the interim Part L changes that are proposed for introduction in June 2022.
With 30% of all UK carbon emissions coming from buildings and 23% of total emissions attributed to heat in buildings, heating is the primary target for carbon emission reduction. Heating in homes contributes 17% of the total UK carbon emissions.
There is an acknowledgement that many existing homes will not be suitable for a heat pump system without at least the undertaking of draft proofing works
Given that these are 2019 figures, the percentage relating to homes must have increased with greater levels of working from home. The strategy proposes a fabric-first approach, which of course is nothing new, but there is an acknowledgement that many existing homes will not be suitable for a heat pump system without at least the undertaking of draft proofing works.
Given that about 25 million homes in the UK are currently running on fossil fuel-supplied heating systems, the challenge to undertake fabric improvement work before heat pumps can be installed will be great.
The strategy states that gas boilers cannot be installed in existing homes from 2035. This assumes that a boiler typically has a 15-year life and therefore that, if it is changed to a heat pump or other low carbon heating system in 2035 or before then, it will contribute to the 2035 and 2050 UK emission reduction targets.
The Future Homes Standard will not permit the installation of gas boilers in new homes from 2025. The potential future need for cooling in our homes is recognised and it is deemed that air source heat pumps will provide that cooling source.
Surely, if we are removing gas heating systems, we are removing gas cooking too
The target is for all homes is to have an EPC rating of C by 2035, but with so much dependent on the EPC rating, assessments will surely have to be more accurate to provide the baseline data for individual homes.
Another consideration is gas cooking. I have seen no mention of it and what will happen. Cooking with gas produces far fewer emissions than heating systems due to the amount of gas consumed, but surely, if we are removing gas heating systems, we are removing gas cooking too – and this will have a cost impact which I hope the government has considered.
Hydrogen may provide a fuel source for housing that is hard to treat in terms of fabric performance and for which a heat pump would be unsuitable. The government is proposing trials of such heating systems at community and district scales, including non-domestic buildings, in the next few years.
Let us hope that the solutions are viable and durable
The strategy outlines the desire for us to take “no regrets” action now which is cost effective with lasting benefit. While this makes absolute sense, let us hope that the solutions are viable and durable and that we are not decommissioning hydrogen systems in the near future or removing mass external wall insulation systems due to unintended harmful consequences.
There will be limited financial incentives to adopt the measures outlined in the strategy and it is proposed that costs will be driven down through innovation, including a new generation of heat pumps that are equal in cost to a domestic gas boiler by 2035. It is of course imperative that we upgrade our existing building stock as soon as possible, but the fear is that many building owners will not be able to afford to do so.
It is of course not only heating systems that we need to consider relative to building retrofit. Quality of homes, building safety, electric vehicle charging and climate change adaptation (flooding and stronger wind protection) are other matters that must also be considered relatively soon.
Considering any one of these in isolation will have financial, human resource, time and environmental impacts and it makes absolute sense for building owners to take a holistic approach to the retrofit of buildings to meet future needs. It will undoubtedly cost more for those who do not do so.
Andrew Mellor leads the development consultancy team at PRP. The practice has been advising what is now the department for levelling up, housing and communities and conducting research around policy and building regulations