As the first rung of the property ladder proves a step too far for many young buyers, the concept of "affordable housing" is the newest addition to the lexicon of the booming property market. The Department of the Environment and local authorities are already involved in such schemes and a number of others are under consideration.

The initiatives, in which buyers acquire a share in their new home instead of footing the entire bill up front, are based on the realisation that while most mortgage lenders are keen to provide finance for groups of people who used to make up large portions of their loan books, ever escalating prices mean that many borrowers simply do not have the wherewithal to make the repayments.

Some experts argue that this is part of the State's transition towards a more European style of home ownership. People will simply start buying homes far later in life and owning your own home in your 20s will be unusual.

But the Government is loath publicly to back this kind of a policy.

Another by-product is the growth in local authority housing waiting lists as more and more buyers abandon hopes of acquiring their own homes.

Some lenders have been bridging the price gap by simply giving out larger loans and by-passing the normal criteria for lending.

While this sort of an approach can help some borrowers it does have its risks. The Central Bank, for one, is adamant that the practice is dangerous.

And the key difficulty remains that it simply does not provide a sufficient boost for many potential homeowners.

It is against this background that the affordable housing route may offer a glimmer of hope for at least some aspiring buyers.

Under the Department of the Environment shared-ownership scheme, people on relatively low incomes can be facilitated in buying a home.

The scheme enables the purchaser to own a portion of the home with the rest being rented from the local authority with the help of a rent subsidy.

Anyone with an income of £8,500 (€10,790) or less is entitled to a £1,200 subsidy, while someone on £12,000 is entitled to £250.

The share of the house being rented can be bought out in full at any time or additional shares can be bought by either adding to the mortgage or paying cash.

Owners can also take out another mortgage to buy out the remaining share when the original mortgage is paid off.

To qualify for the scheme, single-income people must be earning £20,000 or less while two income households can earn about £35,000 depending on how the income is distributed.

Local authorities also operate a separate affordable housing scheme. Houses are offered for sale at cost price and thus at a significant discount.

Purchasers will also be offered mortgage finance at a discounted rate and those on incomes of less than £16,000 will be eligible for a further subsidy. Mortgage rates are a choice between 4.4 per cent fixed-rate loan for five years or at a variable 4 per cent.

Under this scheme if a house is resold within five years the discount on the sale price has to be paid to the local authority, while between five and 10 years a sliding scale payment is applicable.

But however valuable these schemes, they are only of benefit to people on lower incomes. And the current problems are also affecting many middle-income earners who have been left behind by the house-price boom. Several schemes have recently been proposed which target this group.

Last February, Bank of Ireland came up with a proposal which would have targeted people in the £18,000£25,000 bracket. However, the Government opted to put this suggestion on hold on the grounds that it wanted to wait until the supply-side issues had been worked out and prices were flattening.

The danger is that by making housing more affordable in the short term you risk driving up prices over the longer term.

The construction industry has also recently put forward a scheme but it is understood that it is even less likely to get Government approval given the conditions which builders want incorporated into it.

According to housing economist, Ms Annette Hughes of DKM, it is well accepted now that rising house prices can only be addressed in two ways. One is to increase the supply and the other is to reduce demand. "These measures are not designed to do either but rather lead to increased demand which is not sensible in the current climate."

She added that prices have now reached the stage where they are as unaffordable as they were at the end of the currency crisis when average mortgage rates were some 14 per cent, while average house prices were £62,000.

The average person is now paying 31 per cent of his earnings on a mortgage, with prices at £140,000 and mortgage rates of 5.5 per cent.

Bank of Ireland's scheme aims to make this less of an issue for some buyers and it is hopeful that discussions will be reopened on it in the future.

"We were looking at customers who we would normally like to accommodate such as teachers, nurses and gardai as well as bank officials being unable to afford to buy a home but they would have the capacity to repay a percentage of the purchase price. And we felt it would be good to do something," a Bank of Ireland spokeswoman said.

Under the proposals the bank put to Government in February, purchasers would have a mortgage for up to 60 per cent of the purchase price of the house while 35 per cent would be owned by the Government through a housing fund and the remaining 5 per cent would be put up by the home-buyer.

The mortgage would be financed through a 20-year fixed-rate loan with a discount of 1.5 percentage points or 5.25 per cent. However, the bank had not worked out any proposal for people who would want to repay their loans early or to have some flexibility built into the loan.

At the same time, rent would be paid on the 35 per cent of the home. This would be at 3 per cent, resulting in a lower monthly outlay than taking out a standard mortgage for the whole amount. For example on a £100,000 home, the mortgage would be £411.60 and rent £87.50 which is £499. But a mortgage for the full amount would be £652, according to Bank of Ireland.

The bank was planning on releasing £75 million for the scheme, while just over £40 million would come from the Exchequer and, according to Bank of Ireland, that could allow up to 1,250 people to buy homes who otherwise would not afford to do so. The bank scheme also envisaged upper limits on people's salaries as well as on the purchase price of the house. Single people need to be on salaries between £18,000 and £25,000, while joint incomes can range from £28,000 to £35,000.

A third scheme has also recently been sent to Government and discussions will go ahead. This scheme from the Irish Home Builders Association, however, has more conditions attached than either of the others.

Under this proposal builders would build a certain amount of homes priced below those of similar houses in the area and buyers would be able to jointly fund them through a maximum mortgage and rent to an Exchequer controlled fund.

However, in return the builders are looking for mandatory social housing in planning permissions to be abolished as well as more favourable tax treatment for developers. It is understood that the Government views this as too high a price to pay.