Plans for a green recovery announced in the Chancellor’s summer statement on July 8th included a £2BN ‘green homes grant’ which will see householders able to access funding to make their homes more energy efficient.

As the UK pursues its target of net-zero carbon emissions by 2050, focus from the government on the task of retrofitting the country’s housing stock – most of which will still be standing in 30 years’ time – to create more energy efficiency is to be welcomed. However, the scale and nature of the challenge means that much more is required.

Energy efficiency in buildings is not simply a way for individual building users to reduce emissions while saving money on bills. Without significantly reducing energy consumption across the building stock, it will be very challenging to build enough generation capacity to achieve the necessary supply transformation by 2050. We therefore need to elevate energy efficiency in buildings to become a national infrastructure priority.

Heating our homes and workplaces accounts for approximately 20% of the UK’s carbon emissions; most of the UK’s heat is supplied by burning natural gas. This makes the decarbonisation of heat one of the toughest challenges involved in achieving net-zero, and it is the subject of a new report, The path to zero carbon heat, produced by Mott MacDonald in collaboration with UKGBC and a wider working group as part of the infrastructure industry net-zero coalition.

There are three possible routes to decarbonising heat that we explore in the report: replacement of gas as a heat source with green electricity (from renewables, nuclear, and possibly bioenergy with carbon capture, utilisation and storage – CCUS); the widespread use of hydrogen for heating homes; and a hybrid pathway that uses a mixture of both electricity and gas.

Whichever route is ultimately proved to be the best for the UK – and the eventual mix may depend in part on the progress of key technologies – reducing demand by around 25% will be a vital supporting pillar. A year-on-year increase in the deployment of energy efficiency measures will be required, along with the accompanying development of supply chains and skills. Regulation and policy will need to play a significant role, but so can innovations and improved customer packages to include whole house interventions, digital tools and prefabricated systems.

Since the electrification and hybrid pathways will also require millions of homes nationwide to be fitted with heat pumps, it would also be beneficial to promote, encourage and incentivise the early use of this technology. There is a fantastic opportunity to pursue the low-regret installation of heat pumps and hybrid heat pumps, which convert low grade heat into energy that can be used to heat buildings. National, regional, and local initiatives could be brought forward to accelerate heat pump deployment within the next five years.

The net-zero coalition, of which Mott MacDonald is a founder member, represents the best of British industry and innovation, with a wealth of experience in designing, building and operating infrastructure. Each of the member organisations has shown individual leadership on net-zero, and collectively, we have shown a commitment to furthering both thinking and action on this vital agenda. We want to support government and industry in understanding how net-zero can happen, and to deliver projects that demonstrate this. Our report outlines key milestones and dependencies in a series of roadmaps to achieve net-zero heat by 2050, covering the whole energy system from generation, transmission and distribution through to the end-user. It makes detailed recommendations about what can be done in the next five years to put things on the right track.

A ‘green recovery’ is in everybody’s interests, and energy efficiency could play a central role in this through the creation of appropriately-skilled green jobs. We call on the government not only to be more ambitious on this specific issue, but to show leadership and urgency in bringing about a new co-ordinated approach to the decarbonisation of heat overall.

Mott MacDonald is hosting a webinar on July 20th to present the findings of the UK heat decarbonisation pathways report. To register click here.

The work presented in the report was led by Mott MacDonald with support from a working group that comprised: Energy Systems Catapult, Engie, Leeds City Council, National Grid, Pinsent Masons, Delta-EE, University of Leeds, the UK Collaboratorium for Research on Infrastructure and Cities and the UK Green Buildings Council.