A £1 billion programme will improve the energy efficiency of public sector buildings while £2bn will go towards Green Homes Grants for homeowners and landlords to insulate properties.
Sunak also raised the Stamp Duty threshold on house sales to £500,000 from £125,000 until next March to boost the housing market.
“The construction sector adds £39 billion a year to the UK economy.
“House building alone supports nearly three quarter of a million jobs, with millions more relying on the availability of housing to find work.
“But property transactions fell by 50% in May. House prices have fallen for the first time in eight years.
“And uncertainty abounds in the market – a market we need to be thriving.
“We need people feeling confident – confident to buy, sell, renovate, move and improve.
“That will drive growth. That will create jobs.
“So to catalyse the housing market and boost confidence, I have decided today to cut stamp duty.”
Construction Products Association’s Economics Director, Professor Noble Francis said: “The £2 billion funding towards energy-efficient retrofit of the existing housing stock is potentially very promising; but the devil is in the detail, as government has previously demonstrated on energy-efficient retrofit programmes, in particular given the very poor experience of the Green Deal policy.
“In addition, £1 billion for insulating public buildings sounds very good but given this is only for one year, it raises the key question of whether government departments and local authorities have the time or resource to spend this effectively.
“The main risks are that the majority of this money ends up not getting used or that it gets wasted in a rush to spend it. ”
Matthew Pratt, Chief Executive at Redrow, said: “We welcome today’s stamp duty holiday as a positive step to stimulate the housing market and wider economy.
“The measures will have a much-needed domino effect, also supporting suppliers, subcontractors and consultants to the house building industry.”