Written evidence submitted by BRE (DHH0111)

About BRE


BRE is here to contribute to a thriving and sustainable world, by developing science-led solutions to built environment challenges. This includes a rigorous programme of testing products for safety and performance which contributes to the formulation of building regulations, measuring and reporting on issues including energy efficiency, and operating assessment frameworks for the sustainability of buildings.


The UK has a proud track record at the forefront of research and development in the built environment sector which is exported globally and contributes to Britain’s soft power. BRE has been working with developers and owners for many years to reduce the environmental impact of construction processes, materials and operations, as well as providing information and advice on all aspects of the sustainability of buildings throughout their lifecycle.


We are ready to share what we have learned in nearly a century of expertise to help fulfil the nation’s future requirements across buildings, infrastructure and construction, at a time when safety, quality and sustainability have never been more important.



Key points in our response



  1. What has been the impact of past and current policies for low carbon heat, and what lessons can be learnt, including examples from devolved administrations and international comparators?


Decarbonising heat in homes in practice means encouraging people to replace their existing heating systems with low carbon alternatives. Existing systems are predominantly (85%) mains gas boilers (made up of a roughly even split of combination boilers and regular boilers), with the other 15%made up of electric storage heaters, electric direct heaters, oil boilers and LPG boilers. Only a small number of homes already have technologies that are low or zero carbon such as heat pumps and solar thermal systems.


This picture does vary by location: for example, in Scotland more people tend have electric heating and in Northern Ireland there is a greater tendency to use oil boilers. There is also a divide between urban/suburban and rural areas depending on gas network coverage.


Given their predominance nationally, the key to making a significant impact at the national level is to encourage those with mains gas boilers to switch to a low carbon alternative. Past and existing policies, primarily minimum standards and the Renewable Heat Initiative (RHI), have not been designed to achieve this at the scale which is needed. Minimum standards ensure the most efficient gas boilers are installed, but do little to encourage the use of alternative systems.


Whilst RHI potentially offers a financial incentive to install low carbon heating in all dwelling types, the economics of switching are least favourable in homes with existing gas heating systems, simply because mains gas is the cheapest heating fuel. The RHI is also a complicated scheme which has had some practical issues that have limited its effectiveness (especially in Northern Ireland). A lesson from this is that it is very difficult to design a complicated system without flaws or loopholes, only build one up gradually.


There may also be lessons to learn from Scandinavian countries in how to encourage the development and use of good quality district heat networks. Implemented correctly, these can be an enabler of decarbonisation. However, there is no point in simply replacing individual gas boilers with heat network gas boilers (and their additional distribution losses) unless this is certain to be a temporary stepping stone to something zero/low carbon, such as making use of waste heat from a power station or other industrial process, or possibly using green hydrogen.



  1. What key policies, priorities and timelines should be included in the Government’s forthcoming ‘Buildings and Heat Strategy’ to ensure that the UK is on track to deliver Net Zero? What are the most urgent decisions and actions that need to be taken over the course of this Parliament (by 2024)?


The switch from higher carbon systems to low carbon systems, including a mass move away from mains gas boilers, should be the priority during this Parliament.


Government will need to plan to enable this by increasing the robustness of the electricity grid in preparation for much more electric heating via heat pumps (alongside increasing electric car use), helping build a green hydrogen production and distribution system and assisting the biofuels industry to reach its potential quickly. When demonstrably ready (tested by early adopters), policies to encourage a mass market switchover should be enacted, e.g. banning the sale of mains gas boilers as the government has proposed. Policies to further encourage the use of heat pumps can also start immediately, albeit limited by current grid capabilities.  It would therefore be sensible to prioritise their installation in homes off the gas grid where the economics (to householders) are likely to mean this is, in the language of the Climate Change Committee, a ‘no regret option’.


Given the different direction of travel with new build homes (via the new Part L1a of the building regulations), as well as their more certain performance in homes with low heat losses, it seems likely heat pumps will be taken up rapidly in new homes without further incentive – in other words, minimum standards can ensure this.


In the longer term, a mixture of heat pumps and hydrogen boilers may be the solution we need to aim for, with the exact mix determined by the development and evolution of the hydrogen supply chain. This hydrogen will of course have to be green, but it will also have to be provided at a low enough cost that it is worth people’s while to switch away from mains gas. This may be difficult, unless the price of mains gas naturally or otherwise increases. However, this will present government with a difficult choice between seeking to keep fuel costs low to minimise fuel poverty and encouraging the use of low carbon heating systems, which, at least at present, are likely to be more expensive for householders. This highlights the enormous importance of early government support for creating the very efficient electricity and hydrogen infrastructure we need to ensure low prices.



  1. Which technologies are the most viable to deliver the decarbonisation of heating, and what would be the most appropriate mix of technologies across the UK?


A number of technologies, while promising, still require significant development and investment in order to be rolled out nationwide. Among the technologies which currently offer the best prospects for roll out are:



  1. What are the barriers to scaling up low carbon heating technologies? What is needed to overcome these barriers?


The barriers are significant, and include the robustness of the electricity grid, the lack of an existing green hydrogen supply chain and distribution network, the need to modify existing appliances (like gas cookers) to use hydrogen, and the small scale and relative infancy of the bio-fuels market.


There are also some barriers in the supply of a suitable range of heat pumps to operate in all homes (many are currently aimed at the new build market and so have a relatively low output) and the current infancy of the hydrogen boiler industry – although we expect the boiler industry could switch over quickly once the supply is established as the technology is not a major departure from a mains gas boiler.  



  1. How can the costs of decarbonising heat be distributed fairly across consumers, taxpayers, business and government, taking account of the fuel poor and communities affected by the transition? What is the impact of the existing distribution of environmental levies across electricity, gas and fuel bills on drivers for switching to low carbon heating, and should this distribution be reviewed?


BRE suggests innovative policy which would gradually increase the cost of carbon emissions to householders. This could be done by increasing minimum standards periodically to remove the highest carbon systems from market. In the case of gas boilers, this can only be done when there is viable infrastructure in place to handle a mass switch and a proportion of early adopters have already shown it to work in practice.



  1. What incentives and regulatory measures should be employed to encourage and ensure households take up low carbon heat, and how will these need to vary for different household types?


Changes to the EPC may be helpful here. Currently the headline EPC rating is based on running costs, not carbon emissions. The two do not always go hand in hand – e.g. gas boilers are the cheapest solution, so those who ‘upgrade’ to a heat pump will receive a worse rating, despite resulting in much lower CO2 emissions. Similarly, we might well expect green hydrogen to be more expensive than mains gas when it begins to be used, as the currently available bio-fuels are too. Where raising the EPC rating is a requirement (e.g. minimum energy efficiency standards in the private rented sector) none of these low carbon heating types is therefore even an option, let alone incentivised. Greater use of the Environmental Impact Rating (the EIR is a secondary home energy rating, based on carbon emissions, which is provided on the EPC) in setting regulatory minimum standards could be an option.


As mentioned above, upgrading insulation facilitates all the low carbon heating options, particularly heat pumps (which work more efficiently at the lower emitter temperatures allowed for by better fabric insulation). Progress on insulating the housing stock has rather stalled in the last five years. It is important it accelerates again in the next five, supported by the Green Homes Grant and Social Housing Decarbonisation Fund, for example.



  1. What action is required to ensure that households are engaged, informed, supported and protected during the transition to low carbon heat, including measures to minimise disruption in homes and to maintain consumer choice?


Government needs to set a clear high-level roadmap and explain it clearly to the public so that they are aware of the key changes that will affect them directly, and are aware of decisions that they could choose to make in the near future, such as replacing a gas oven or boiler with a greener alternative. Households will not only need to alter their purchasing behaviour but also learn how these technologies are used in homes. For example, the way low-carbon heating systems are optimally used is quite different from the current and historic cultural norms for the UK. This will be important to prepare householders for the transformation that is needed and start to build demand for greener technologies, particularly for retrofitting existing homes.


As carbon emissions and other factors such as heat loss are typically deemed ‘invisible’ e.g. they cannot be seen like other issues such as disrepair, the reasons for action need to be outlined in a clearer way for householders to understand. Measures for doing this could include the provision of a training scheme for those who will need to explain the importance of these schemes to householders – who could include local authority or utility company staff. This could also include the importance of sequencing measures within dwellings to ensure that disruption to the householder is minimised.


There also needs to be a robust framework in place to ensure quality of retrofit is maintained. Past experiences of sub-standard works have undermined public and investor confidence in some aspects of green retrofit and there is a risk that these will be repeated unless standards are created and adhered to.



  1. Where should responsibility lie for the governance, coordination and delivery of low carbon heating? What will these organisations need in order to deliver such responsibilities?


The UK government will need to coordinate this, since the issues to be resolved are UK-wide ones, such as the National Grid, which will affect nearly all households and homes. With a strong national strategy and the right resources and training, local, regional and devolved governments will then be in a better position to develop local and regional heat plans, like the Local Heat and Energy Efficiency Strategies being piloted in Scotland. In Ireland, the Climate Action and Low Carbon Development (Amendment) Bill makes provision for local authorities to play a bigger role, requiring them to create a 5 year “local authority climate action plan” which sets out the mitigation and adaptation measures to be adopted. The plan needs to align with neighbouring local authorities and is then subject to public consultation – another way of engaging householders and the wider society such as businesses. It is likely that this will require significant extra resource and training for local authority staff.


In order to do this, local and regional authorities will first need a detailed understanding of their buildings and the stock condition. From over forty years of conducting the English Housing Survey, BRE has substantial insight into the condition of housing and its potential for improvement. We have developed dwelling level models to provide the intelligence required to plan improvement strategies and effectively target resources. These models have provided house condition and energy efficiency data to over 230 local authorities so far. BRE is happy to share further insight.  


December 2020