The UK government has formally backed plans to ban gas and “hydrogen-ready” boilers from newbuild homes in England from 2025, in a long-delayed consultation on low-carbon building standards. The proposals could mean heat pumps being installed as standard as part of measures to make all new homes “net zero ready” from 2025. The consultation rules out the use by housebuilders of all fossil fuel heating systems including gas, hybrid heat pumps and hydrogen-ready boilers, after a finding that there was “no practical way to allow the installation of fossil fuel boilers while also delivering significant carbon savings”. The net zero standards are considered key to the government’s plan to meet its legally binding target of net zero emissions by 2050. However, the consultation has been delayed amid growing controversy over the government’s links to the housebuilding sector. The consultation was originally expected in March, before it was delayed to the summer and then scheduled for the end of the year. The plans will be finalised by next March. Green groups claim that the government has allowed housebuilders to save billions of pounds by delaying the new standards, which are expected to increase construction costs. In October, the Guardian revealed that at least 10% of donations received by the Conservative party since 2010 – about £40m – came from property developers, real estate tycoons and others connected with the construction industry. David Cowdrey, a director at the MCS Foundation, which accredits home energy installers, said: “Making heat pumps the default heating source for all new homes and banning gas and hydrogen boilers is absolutely the right step for the climate and for households’ energy bills. “Allowing fossil fuel or hydrogen heating in new homes would have locked in high bills and high carbon emissions for a generation. It is a huge relief that we are escaping that possibility and that the government has recognised the conclusive evidence that heat pumps and heat networks are the only viable option for getting our homes to net zero and ensuring low bills for people in new-build homes.” Juliet Phillips, a senior policy adviser at the climate thinktank E3G, said the decision to ensure all new homes were built to be highly efficient and warmed by low-carbon heating was “perhaps the most popular and common sense of climate policies”. She said: “This is great news for homebuyers, who will save money on energy bills and avoid the need for costly retrofits in the future. It’s also great news for the UK’s clean-tech industry, providing the long-term policy certainty needed to boost investment in skills and supply chains.” The requirement for all new homes to be built to highly efficient standards was originally proposed in 2006, which would have required all new houses to be “zero carbon” and generate as much energy as possible onsite from 2016. This proposal was scrapped in 2015. About 1.5m homes are estimated to have been built without these low-carbon fittings since 2015. The cost of retrofitting these properties is likely to reach £30bn to £45bn.