Sales of gas boilers for homes should be phased out by 2033 as part of efforts to cut greenhouse gas emissions from heating, climate advisers have said.

Tackling the role of emissions from buildings, which account for 17% of the UK’s climate pollution, is a key challenge, with little progress made in recent years.

The Committee on Climate Change said a national investment programme is needed to green homes fully, at an average investment of less than £10,000 per home over the next 30 years.

It will provide jobs, cut fuel costs and reduce fuel poverty, improve health and comfort in cosier homes and improve air quality, the advisers said.

But what is actually involved in cutting carbon from homes?

The first priority is to reduce the amount of energy that is wasted in heating a home, which requires a programme to make millions of flats and houses more energy-efficient with insulation and double or triple glazing.

The main source of direct emissions for domestic properties is heating and hot water, which in the majority of homes is provided by a boiler fed by natural gas from the grid.

That has to be replaced with a greener alternative, such as heat pumps, which are powered by electricity, working a bit like a fridge in reverse to generate heat from the outside air, or sometimes the ground, to provide heating and hot water in the home.

Air source heat pumps look like an air conditioning unit on the outside of buildings, and may need bigger radiators or underfloor heating to work best. They work more efficiently in buildings that are energy-efficient.

There is also potential to replace gas boilers with hydrogen, or even a hybrid of hydrogen boilers and heat pumps, but they will need efficient homes too to reduce the demand for hydrogen which has to be manufactured.

Hydrogen is most likely to be used in areas where the gas is being manufactured, for example to provide energy for industry.

And there will be a role for district heat networks, which pipe hot water in underground pipes to carry heat to homes from a central source, such as a combined heat and power plant or even former mines.

Around a fifth of heating is expected to be provided by heat networks by 2050, and all of those which are currently supplied by fossil fuel heat and power plants will need to covert to low carbon sources by 2040.

The Committee on Climate Change has set out a series of target dates the Government needs to meet to stay on track to decarbonise homes, including:

– By 2025 at the latest, all new buildings are zero carbon, with high levels of energy efficiency, and heat pumps or low carbon heat networks providing heating.

– By 2028, rented homes are to meet a decent standard of energy efficiency, while homes with mortgages should achieve the standard, EPC level C, by 2033, and no homes should be sold without meeting that level by 2028.

– New boilers should be hydrogen-ready by 2025, so they can use hydrogen instead of natural gas, and sales of oil boilers for off-grid homes should be phased out by 2028.

– By 2030, a million heat pumps a year are being sold for new and existing homes.

– Sales of gas boilers should be phased out by 2033, except in buildings in zones designated for district heat or hydrogen networks.

Committee chief executive Chris Stark said there needs to be a national strategy for cutting carbon from heating.

But decisions have to be made at a regional and local level, playing to local strengths and involving communities in the decision, so that individuals know what kind of heating system they will be taking on in the 2030s.

And he said the recent Climate Assembly, in which members of the public examined and debated ways to cut emissions to net zero, showed people are most concerned about reducing the disruption it would involve.

“It’s not a question about climate change, the impact on the climate, it’s not really a question about cost either, it’s practicality that will matter,” he said.

Commenting on the report, Professor Rob Gross, director of the UK Energy Research Centre (UKERC), said: “It is hard to overstate the scale of the challenge facing housing.”

The Climate Change Committee was clear on the need to get on and roll out heat pumps, he said, and warned UKERC analysis has shown that the current rate of heat pump installation would take 700 years to reach the targets.

“The opportunity to create jobs in building retrofit is enormous but we fear a huge gap in skills and household awareness,” he added.