Published in advance of Chancellor Rishi Sunak's statement on a Green Homes Grant for some households, Elmhurst’s Manifesto for Growth outlines the key areas that it wants the government to focus on post-coronavirus, with a bigger commitment to improving the energy efficiency of the existing housing stock at the top of the list.

However, it is also warning that much more data on owner occupied homes is essential before jumping in with huge amounts of insulation work and other building improvements.

Martyn Reed, managing director of Elmhurst Energy, said: “I think it’s very encouraging that the Chancellor understands the benefits of a green homes programme. Such an initiative, at scale, could create Britain’s biggest, most exciting and most transformative infrastructure project of all time, with significant benefits for our health and the environment, as well as creating a huge boost to jobs, skills and economic recovery.

“In particular, there is a massive opportunity in the owner occupied sector. But at the moment it’s largely unchartered waters. The average tenure of an owner occupied property is over two decades and many of these properties have never been energy efficiency assessed. We estimate that there are approximately 14 million properties in the UK without an Energy Performance Certificate (EPC) as they have never been sold or rented out in at least the last 10 years.

“This presents us with a huge challenge, as we cannot yet evaluate the resources needed to bring these homes up to a reasonable standard of energy efficiency. Nor can we easily target future financial incentives, such as green finance or tax breaks for better insulated homes, without this essential data.

“To kick start a mass retrofit programme, every home should receive an EPC and a plan for whole house retrofit within the next 12 months.”

Elmhurst’s Manifesto for Growth also outlines other measures that could stimulate growth in the energy efficiency market, including finding ways to combine information in asset ratings, occupancy ratings and smart meter data to create the ‘golden triangle’ of assessment that will inform policy on a local and national scale.

It has also called for urgent technical updates to SAP and SBEM methodologies to ensure they remain fit for purpose and don’t stifle innovation in new energy-saving technologies, plus measures to close loopholes that perpetuate the ‘performance gap’ in new homes, and the removal of any exemptions that mean some buildings can get away without an EPC at all.