Britain's housing stock requires a vast - and expensive - retrofitting programme if government climate targets are to be met, according to a new report.
Progress so far has been too slow, claims a study by the Institution of Engineering and Technology and Nottingham Trent University.
Hundreds of millions of pounds should be ear-marked for upgrading the housing stock with renewable energy technologies and insulation. The rewards would be lower energy bills and improvements to health, the report claims.
Around a fifth of the country's greenhouse gas emissions are from domestic housing - mostly relating to heating and hot water. Attempts to minimise these emissions have largely failed, making a new upgrade programme necessary - one that would make homes low-carbon for the next three decades.
A dramatic shift in policy is required to cut greenhouse gases by 80% by 2050 - the target the government has agreed to.
Marjan Sarshar, professor of sustainability and the built environment at Nottingham Trent University, said: “A national programme for a one-off deep retrofit [of all residential property] is needed. Costs will come down as we build up the supply chain capacity.”
The study urges work on social housing stock first, accounting for 4.5m properties. Costs can be managed by tackling an entire area at a time, say researchers.
With retrofit estimates at around £17,000 per household, the costs will be substantial, but will pay dividends in lower energy bills and warmer homes. The latter benefit will also help costs to the NHS, which spends around £1.4bn annually treating health problems arising from poor quality accommodation.
The researchers suggest a one-off retrofit would cut long-term maintenance costs, which for social housing amount to £5.2bn annually. Renewables like solar panels, together with modern insulation techniques, would dramatically cut energy bills for social housing residents, who spend £4.2bn each year on heating and hot water.
The report suggests one-off retrofits which would see upgrades to walls, roofs, windows and doors, alongside renewable systems.
While the technology required for such a national retrofit is accessible and understood, at present, there is no large-scale industry in place to undertake the work.
Among the reasons households have largely failed to undertake their own retrofits are: high costs compared to perceived energy savings; and a lack of leadership from the government.
According to the researchers, even if houses built now are built to the requisite standard, the government would fail to meet its emissions targets by 2050 - making retrofitting existing homes a must.