In that case, it will require retrofitting millions of buildings with better insulation and double glazing.

Research from Data Insights company Impact Data Metrics, which was produced by analysing more than 19 million records using a machine-learning and AI-driven system, shows that it will cost between £6,220 and £11,120 to upgrade each property to reach EPC C or better.

At the lower range, this equates to a total of £65.4 billion spent over the next five years, and £118.1 billion at the higher range.

Government data indicate that domestic energy consumption is indeed declining; between 2020 and 2023, there has been an overall decrease in energy consumption, ranging from 8.1% in some local authorities to 17.8% in others.  But clearly, more needs to be done.

Geoff Wainwright, chief executive of Impact Data Metrics, said: “Against a challenging economic backdrop for the government, our research highlights the scale of the retrofit challenge ahead if we are to get anywhere near meeting our net zero ambitions.”

As of 2030, all private landlords will be required to meet an EPC rating of C or equivalent in their properties – up from the current level of EPC E - but these regulations will not affect private homes.

IDM’s analysis of the data indicates that this could be as many as 1.1 million privately rented homes with an EPC rating of less than C, of which 51,000 will not reach a C rating despite improvements, leaving an estimated bill for upgrades between £6.7 billion and £12 billion to be met by private landlords.