Image copyright Getty Images Image caption First time buyers in many areas of England will find a two-bedroom house costs more than the maximum they can purchase with a Help to Buy Isa

Would-be-homeowners in large parts of England are being priced out of a government scheme to help first-time buyers, a BBC investigation has found.

The Help to Buy Individual Savings Account (HTB Isa) was introduced last year to help people save for a home.

In many areas, the average price of a starter home exceeds the maximum purchase cap of £250,000, or £450,000 in London.

Chancellor George Osborne said the scheme was aimed at first time buyers.

The HTB Isa was introduced in December to allow first time buyers to put their deposit into a tax-free savings account and get a 25% bonus, up to a maximum of £3,000, when they buy their home.

However, the bonus is only available if the purchase price does not exceed the cap. Housing charity Shelter said it only helped "the lucky few" and the government should focus on building more homes.

The English Regions data unit analysed the average asking price of properties in almost 1,000 local areas on the property website Zoopla.

Help to Buy Isa: Your stories

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How does a Help to Buy Isa work?

Our analysis of two-bedroom starter homes found:

Overall, outside London, two-bedroom homes exceed the cap in 28% of areas

Average asking prices exceed the cap in 67% of areas in the South East, 65% in London, 61% in the South and 53% in the East

This compares to less than 5% of areas in the North East, the Midlands, Yorkshire and Lincolnshire

Ferryhill in County Durham had the cheapest average asking price, at just over £45,000.

The most expensive area outside London was East Molesey in Surrey, where the average price is £551,025

For other types of property, our analysis found:

In London, an average two-bedroom flat exceeds the cap in two thirds of boroughs, while one-bedroom flats exceed the cap in a third of boroughs

Only 10% of average three-bedroom homes in London are below the cap

Outside London, the highest average price advertised for a one-bedroom flat was in Berkhamsted in Hertfordshire, £408,000.

Almost all of the most expensive areas for one-bedroom flats were in southern England, with the farthest north being Matlock in Derbyshire, where the middle of the range of apartments was £250,150.

Media playback is unsupported on your device Media caption The challenge of buying a starter home

Personal finance commentator Martin Lewis, of MoneySavingExpert.com, said savers should not be put off opening a HTB Isa.

He said: "It is a cash giveaway from the taxpayer.

"Even if you don't end up using it to buy a house, you still have savings with a very favourable rate of interest."

He added that from next year the government was launching its Lifetime Isa, with a limit on house purchases of up to £450,000 and that people could transfer in their savings from an HTB Isa.

First-time buyer help: What happens elsewhere?

In Australia, first time buyers in some States are given a grant of up to $10,000 (£5,091) when purchasing a property

In the US, various States offer incentives. In Florida, for example, the State government uses tax credits to make mortgages easier to afford once the property is purchased

China has a mandatory deposit of 25% or more, but this is cut to 20% for first-time buyers in large cities such as Beijing

Campbell Robb, chief executive of housing charity Shelter, said: "Soaring housing costs have left millions of people stuck in a rent trap and struggling to save anything towards a home of their own.

"The Help to Buy Isa only helps the lucky few who are better off, or able to live with their parents while they save for a deposit. For the vast majority of renters who want to move forward in life and put down roots, this scheme brings them no closer to that dream.

"If the government genuinely wants to help the nation's renters get a foot on the housing ladder, it needs to look beyond quick-fix schemes, and invest in homes that people on ordinary incomes can actually afford."

Speaking to BBC South East Today in Shoreham-by-Sea, West Sussex, Mr Osborne said: "We want it to be available for people getting on the housing ladder rather than [for] more expensive homes.

"The scheme goes from strength to strength and we can always look to improve it."

A Treasury spokesman added: "The property price cap allows the government to target support at those who are saving to buy their first home."

He added that by March 2016 more than 150,000 people had used the government's other Help to Buy equity loan and mortgage guarantee schemes.

Analysis, Richard Donnell, Hometrack

The cap on purchase prices for a Help to Buy Isa should encourage house builders to develop smaller homes, a property expert says.

Richard Donnell, research and insight director from Hometrack, said: "In order to appeal to a wider group of buyers, builders need to start building smaller houses to offer at the lower price point to help first time buyers get on the housing ladder.

"There is a lack of supply of two-bedroom homes and this keeps the price gap narrow and relatively close to three-bedroom home prices."

Hometrack figures, based on prices paid for homes between June 2015 and January 2016, show how prices for two-bedroom homes at the higher end of the range cost as much as or more than the lowest-priced three-bedroom properties in the same area.

In Elmbridge in Surrey, an average two-bedroom home in the upper price range went for an average of £459,963, while a lower range three-bedroom home sold on average for £430,000.

Reporting team: Daniel Wainwright, Paul Bradshaw, Pete Sherlock, Helen Catt