Help to Buy has increased home ownership and housing supply.
However, most of those using the scheme would have been able to buy a home anyway.
Furthermore, buyers have saved less than 1% by using the taxpayer-funded scheme.
The damning verdict on Britain’s most expensive housing initiative comes today from the National Audit Office.
The scheme was introduced in April 2013 and applies to new-build homes only.
It has come under attack from agents for distorting the traditional first-time buyer market and reducing the overall second-hand homes sector.
The National Audit Office points out that all eligible applicants are given equity loans, and there are no targets.
By last December there had been some 211,000 loans amounting to £11.7bn.
Some 38% of all new homes bought between April 2013 and last September were supported by Help to Buy loans – around 4% of all house purchases.
Excluding London, between January 2016 and last September, almost half of all new-build sales (46%) were made with Help to Buy.
According to the Ministry of Housing, 37% of households would not have been able to buy any property without the scheme. And while three-fifths of buyers could have bought a property without Help to Buy, it might not have been the home they wanted.
Today the National Audit Office said that buyers who have used the scheme have not had a bargain: they have saved less than 1% than if they had bought a similar property without Help to Buy.
The NAO warned: “However, new-build properties typically cost around 15-20% more than an equivalent ‘second-hand’ property (termed the new-build premium) and some buyers who want to sell their property soon after they purchase it might find they are in negative equity.
“The scheme has supported five of the largest developers in England to increase the overall number of properties they sell year on year, thereby contributing to increases in their annual profits, which have all increased since the scheme’s start.”
The NAO also warns that while the Government expects to recover its investment by 2032, it is exposed to market risks such as house price changes.
It is calling on the Government to undertake a detailed assessment of Help to Buy on the wider housing market.
Gareth Davies, head of the NAO, said: “Help to Buy has increased home ownership and housing supply, particularly for first-time buyers. However, a proportion of participants could have afforded to buy a home without the Government’s help.
“The scheme has also exposed the Government to significant market risk if property values fall, as well as tying up a significant public financial capacity.”
He said that without knowing Help to Buy’s long-term effects on the market, “we cannot say whether the scheme has delivered value for money”.