The figures come from a new report by the Sustainable Energy Authority of Ireland (SEAI), which also showed applications for home energy upgrades up 140%.

The number of homes upgraded to a BER B2 energy rating almost doubled to 8,481.

The upgrades were supported through Government-funded SEAI grant scheme, with 4,438 fully funded upgrades for low-income households completed throughout last year.

In total, capital expenditure on the national retrofit programme was €188 million last year, up 90% on 2021. CO2 emissions were reduced 40.27kt, an improvement of more than 80% on 2021.

Green Party leader Eamon Ryan TD said: “Our aim is to retrofit 500,000 homes to a BER rate of B2 and install 400,000 heat pumps in existing homes by 2030, to make them warmer, healthier, more cost efficient and better for our environment.

“The message from the most recent IPCC report on climate is clear. We need to go further and faster in tackling climate change. However, this same report says that we have the solutions, including the solutions to implement better energy efficiency which retrofitting is all about.”

Dr Ciaran Byrne, Director of National Retrofit at SEAI, said: “Overall, significant delivery targets for home energy upgrades were achieved last year. It is evident from this report that momentum in applications and delivery of home upgrades built steadily through the year.

“However, the factors driving uptake of home energy upgrades including increased grant levels, One Stop Shop service launch, cost of living and energy crises, were somewhat offset by the impacts of inflation, labour shortages and supply chain delays on contractors' ability to capitalise on the demand.

“This led to a situation where, for much of the year, there was an unmet demand for home energy upgrades. The One Stop Shop and contractor base is continuing to scale up to meet this burgeoning demand. Construction sector inflation and material supply chain constraints are likely to remain significant risks in the medium term.”