The coalition government has already announced plans for 100,000 cheap starter homes for people aged under 40.

The Prime Minister said today that the Tories would double that target if elected, to give more people the security of owning their own home.

Currently, builders can face an average bill of £15,000 per home in Section 106 affordable housing contributions and tariffs, often adding tens of thousands to the cost of a site.

Under the initiative, house builders will be exempted from paying planning gain contributions on brownfield sites if they agree to offer homes developed on them to first time buyers at 20% below market price.

Already many of the country’s councils and 30 house builders, including Taylor Wimpey and Bellway, are pledged to run the new Starter Home initiative.

Building on the first homes is expected to start within months, the government said.

As well as reducing the prices of properties for young buyers, a Design Panel, including renowned architects Sir Terry Farrell and Sir Quinlan Terry have drawn on housing designs from across the country for home builders to consider for Starter Homes developments. (see below)

Cameron said: “We’ve shown what we expect starter homes to look like – not rabbit hutches or shoeboxes, but decent, well-built, homes with gardens – places to start and raise a family.”

“This policy will work, not least because property developers, the builders, the building industry are all coming out and saying they will deliver it,” he added after his speech in Colchester this afternoon.

He added that the UK had suffered from a chronic shortage of housebuilding for decades but that action taken during the past five years meant the country was on course to deliver 200,000 new homes a year by 2017.

He said a future Conservative government would also extend the Help to Buy scheme in England until 2020 and make it easier for council house tenants to buy their homes.

Rhian Kelly, CBI Business Environment Director, said: “Starter Homes are a step in the right direction to building the 240,000 new homes a year we sorely need, but we would want to see more detail on how the proposals could be implemented on the ground.

“It’s important that policymakers of all shades don’t rule out options for land use, including low-quality green belt.

“Our chronic national housing shortage is a serious headache for businesses and those wanting to get on the housing ladder. Whilst the Help to Buy scheme has been useful, further bold action really needs to be taken to improve the supply of affordable housing to rent and buy.”