When you are looking in at the property market from the outside, the gap between yourself and the home-owning classes can look unbridgeable.

Just as it looks like your savings might finally stretch to a deposit, house prices expand at a greater pace than your bank account and the market moves further away than it was before you started. And the longer the story goes on, the harder it gets.

The crux of the matter, as with so many other troublesome situations in life, is money, or lack thereof. Just how much of a deposit is required to purchase a home these days remains a point of discussion, but there are figures in circulation that offer some guidance.

When reporting results last week, Irish Life and Permanent said that the average mortgage awarded to first-time buyers by Permanent TSB in the first half of this year amounted to 79 per cent of the property's value.

When this ratio is considered alongside the average national first-time buyer price of about €195,000, it emerges that those entering the property market are now in a position to put down a breathtaking €40,000 (at least) before the deal is done.

While a considerable number of the State's first-timers will buy as couples who can share the deposit, the extent of the initial outlay still raises a few questions. Chief among these is the simplest query of all: where do these people get the money?

The most reassuring response is that parents are stepping in with some cash to help their little darlings to gain a property foothold.

This is, in many cases, a reasonable theory, since the past few years have seen a large number of parents become something approaching rich as the value of their own homes shoots into the stratosphere. And surely it is only natural that they would want to share their winnings with their offspring.

But of course not all virgin buyers are sufficiently lucky to have generous mummies and daddies. For these, the options for raising a deposit are much more limited.

The first thought of many would-be buyers in this circumstance will be to borrow from their bank or building society to fund the deposit.

Ms Sarah Wellband of mortgage advisory firm, Rea, says this approach is perfectly valid but warns that it will eat into the borrowing capacity that people may otherwise have.

This is especially true, she warns, now that lenders tend to take net income rather than gross income as the best indicator of a borrower's means.

"For example if a couple have a joint income of €60,000 and no loans, Permanent TSB will lend them about €250,000 and Ulster Bank would go to €280,000. If however they had a loan repayment of, say, €400 per month, their borrowing capacity would fall to €180,000 and €215,000 respectively.

A variation on this route would be for a buyer to approach their credit union for a loan. Credit union loans do not feature on the radar of the Irish Credit Bureau and will thus not show up if a homeloan provider runs a check on a would-be customer's credit history.

Ms Wellband points out however that this avenue may not be as straightforward as it seems, since borrowers will be obliged to prove where their deposit money is coming from so that the lender in question can satisfy money laundering rules.

"If the lender sees any reference to credit union savings they will require a statement showing that the money is in deed savings and not a loan," she says.

So if borrowing is not as simple as it seems, what other options are there? Unless you are a well-paid professional who fits into the criteria for Ulster Bank's 100 per cent loans, it seems the parents are once again top of the list.

If you are fortunate in this regard, protocol requires that the parent advancing the cash confirm in writing that it is a gift rather than a loan and that they will not take a legal interest in the property.

If the parents do want a share in the house or apartment, they will need to draw up a separate legal agreement.