Compared to the stock market, bricks and mortar have never appeared so solid. In the first six months of this year one in five properties were bought by investors with around half of these going to new landlords investing in buy-to-let properties for the first time.

Stock market jitters are only one of several factors boosting the residential property investor phenomenon. Last year's budget which reintroduced interest relief on borrowings for rented accommodation and a more favourable stamp duty regime brought investors back into the market. And they certainly are back. In 2001 only 5 per cent of residential property was bought by investors.

Homeowners, particularly in mature areas of Dublin, who are at least five years into their mortgage, are sitting on a considerable chunk of equity which, thanks partly to aggressive marketing by some financial institutions, they are beginning to realise could be put to some investment use. New mortgage products, particularly interest-only mortgages, are enticing buyers into the market. Borrowers pay only the interest on the mortgage in the first three to five years. As a result, repayments are lower than on a mortgage where both the capital and the interest are paid.

In an investment world bogged down by jargon and statistics, buying to let is something that everyone can understand.

What's more it seems easy: remortgage your family home, buy an apartment and get someone else to pay your mortgage is the basic theory. Add in the possibility of capital appreciation, steady rents and the seemingly never-ending supply of likely tenants and the attraction is clear.

However, as the small print of every investment will hint at, it's not as simple as it seems. The long-developed buy-to-let market in London has all but collapsed for investors due mostly to oversupply. Too many small-time investors with the same idea has led to too many rental properties in certain price brackets and severely reduced rents.

While the buy-to-let market here is only in its infancy, would-be investors would be wise not to base their figures simply on the current rent-to-mortgage ratio but to take a long-term, realistic view.

Unless a buyer has between 50 and 60 per cent of the purchase price of an apartment, they are unlikely to be able to charge enough rent to meet monthly repayments. Also, rents, which were increasing by as much as 20 per cent per year, have stalled this year and market analysts expect that this will remain the same for the next year at least.

Investors should also bear in mind that property is a relatively non-liquid investment - once money is tied up in property, it may not be possible to cash it in as quickly as desired.

"Property is not a high-yielding investment and the market has changed," says Mr Brian Healy, head of property finance at EBS. "I always advise anyone thinking of investing in property for the first time to talk to someone else who has done it to get an idea of the potential headaches involved."

A typical profile of a buy-to-let EBS customer, according to Mr Healy, is a homeowner in their mid to late 30s, who is sitting on spare equity in their home and who has seen an increase in their disposable income over the past five years due to wage increases.

The increased supply of lettable accommodation in Dublin in the €800 to €1,400 per month category (typically a one or two bedroom apartment) has given increased power to tenants. While rents are still relatively high, they are now static with little or no increase on last year. At the higher end of the market, where monthly rents used to average €2,500, they have fallen by as much as 10 per cent in the past year.

Two years ago, landlords could advertise smart apartments secure in the knowledge that there would be a queue of desperate people willing to pay 20 per cent more than the previous tenants. Not any more.

"Landlords certainly have to be more flexible," says Ms Kate Sissons, managing director of Christies, an estate agency with an active letting and management division. "If a prospective tenant wants the colour of the walls changed or doesn't like the furniture, landlords have to be prepared to do it to get good-quality tenants."

Buy-to-let investors should be prepared to take a long-term view, which in property investment terms tends to be eight to 10 years. "Capital appreciation rather than rental income is what investors should be considering," says Mr Paul Murgatroyd, economist with Douglas Newman Good estate agents.