Written evidence submitted by the Mineral Products Association (DHH0088)


About MPA


Q2. 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)?


  1. Thermal mass is a property of buildings that is very well understood and has been used to optimise buildings’ thermal performance for centuries.  Different materials absorb and release heat at different rates, with heavy building materials such as concrete, stone or bricks and mortar having high thermal mass and moderate conductivity and so absorbing a lot and releasing it slowly over time. By contrast, light building materials such as timber absorb and release it too slowly to be useful, while steel does so too rapidly to synchronise with the daily temperature cycle.[1]


  1. The benefit of this is smoothing out the temperature curve over the day, so that when the weather is at is hottest heat is absorbed, thus cooling the interior, and released at night. Thermal mass also means buildings do not cool as much in cold weather, reducing heating requirements in winter.


  1. Thermal mass is an inexpensive way to improve thermal efficiency that requires no new technology but does require material choice and building design to be optimised. For example the orientation of buildings in relation to the sun can be used to maximise the heat gain to be stored in winter.


  1. Looking to the future, thermal mass is also set to form a key element in Demand Side Response (DSR) control systems, which smooth out power use in buildings to counter the intermittency of renewables supplying the national grid. DSR can be configured to use thermal mass for storing and later releasing heat or coolness provided by heat pumps/chillers at times of low grid demand, when power is cheap and renewable energy would otherwise not be fully utilised. In addition to lower running costs, this approach enhances the carbon efficiency of grid-supplied power. An example of where DSR and thermal mass have been used to cut operating costs is the Bullring shopping centre in Birmingham, which delivered savings of £23,000 over an initial six-week trial period, according to owner Hammerson. The use of DSR in this manner represents a significant development for the future use of heavyweight materials, even if it is something that Life Cycle Analysis tools cannot necessarily take account of at present.


  1. Prioritising thermal efficiency reduces energy demand for both heating and cooling, the latter of which will become more significant as the climate warms. Even if heat is fully electrified and electricity fully decarbonised, this will reduce the amount of generating capacity needed and thus make reaching net zero cheaper. If any fossil fuels remain in the heat system by 2050, it will directly reduce emissions.


  1. The production of the building materials that have the best thermal mass properties is in the process of decarbonisation. UK Concrete recently published the Concrete and Cement industry road map to beyond net zero, setting out the key technology levers that will enable each tonne of concrete and cement to remove more carbon dioxide from the atmosphere than it emits.[2]



Q3. 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?


  1. There will inevitably be a mix of technologies and approaches across different types of buildings but we would stress that making best use of the thermal mass in any building’s structure will help any heating or cooling technology be used most efficiently.


  1. Decarbonising the production of heavy building materials will require a mix of technologies including fuel switching and CCUS, as well a decarbonising the electricity grid and transport, as covered in the road map.



Q5. What are the barriers to scaling up low carbon heating technologies? What is needed to overcome these barriers?


  1. For thermal mass, attitudes, knowledge and prioritisation of how to best use it are the main barriers. There are no technical blockers. But enthusiasm for novel solutions can lead designers, architects and specifiers to overlook tried and tested approaches.


December 2020

[1] For more detail on thermal mass see The Concrete Centre, available to download for free at https://www.concretecentre.com/Publications-Software/Publications/Thermal-Mass-Explained.aspx

[2] https://www.thisisukconcrete.co.uk/TIC/media/root/Perspectives/MPA-UKC-Roadmap-to-Beyond-Net-Zero_October-2020.pdf