Prime Minister Keir Starmer's party wants 1.5 million new homes built by 2029 amid a housing shortage -- a figure many experts believe is optimistic.

Energy Secretary Ed Miliband said proposals announced Friday mark "a monumental step in unleashing this rooftop revolution".

The government said: "New homes will also have low-carbon heating, such as heat pumps and high levels of energy efficiency, cutting people's energy bills and boosting the nation's energy security with clean, homegrown power."

It added in a statement that "a typical existing UK home could save around pound530 ($717) a year from installing rooftop solar."

"The proposed Future Homes Standard would see building regulations amended to explicitly promote solar for the first time, subject to practical limits with flexibility in place for new homes surrounded by trees or with lots of shade overhead," the government said.

Environment campaign group Greenpeace welcomed the policy, while urging the government to go further.

"This is a great example of how climate solutions can not only cut planet-heating emissions but also improve people's lives," its head of politics, Ami McCarthy, said in a statement.

"Now ministers need to urgently reform the UK's energy system as a whole and stop gas from setting the price of electricity so that everyone, whether living in a new build or not, gets to enjoy the lower bills that cheap, clean renewable power can bring."

Britain has set its sights on delivering a net zero carbon economy by 2050.