Home exchanges are popular again as people count the cost of holidays - and the internet has made them easier. And they work - just don't drink all their wine, writes SANDRA O'CONNELL.

And she won't even be there to keep an eye on them. She'll be in their spacious family apartment in an Alpine part of Austria.

Having swapped homes before, with a family in Brittany, she knows exactly what to expect.

"We were going to do a campsite holiday with the kids in France but it was working out at around €2,000 for a week. This way we don't have to pay accommodation or car hire, just flights. The financial savings are huge."

Ryan arranged the swap through Intervac, a membership-based organisation initially set up half a century ago by a pair of teachers looking to make the most of their long holidays.

The organisation is now open to all. For a subscription fee of €85, details about your house, your available dates and preferred swap locations are all posted on its website while you get to view those of other people.

Interest in the concept is once again growing here.

"During the years of the Celtic Tiger boom we saw our membership fall from 400 to 200. Over the past 18 months that has grown back up to 300," says Frank Kelly, who has managed Intervac in Ireland since 1973 and is a veteran of more than 20 house swaps.

It isn't just the changing economy that has driven interest. "The internet has revitalised house-swapping in that people put up as many photographs of their house as they like, so you know exactly what kind of property you are getting."

It's not for everybody however. "Last week I had a man ring me and go through the application process with great enthusiasm only to call back two days later and ask me to take his details down because his wife couldn't cope with the thought of having strangers stay in her house."

It's perhaps an understandable anxiety, but, as he points out, house-swapping is a very mutual arrangement.

Also, by the time a house-swap takes place, a good relationship will have been built up by e-mail and phone.

"The key is to communicate as much as possible with the people you are thinking of swapping with so that each party knows exactly what they are getting and there are no surprises."

The only negative incidents he can recall in three decades were a car accident - "where the visiting family fixed the car but never told the owners about the accident" - and a French family who, perhaps foolishly, left a note encouraging their guests to help themselves to wine.

"Turns out they meant wine in the kitchen, not the good stuff they had down in the cellar," said Kelly.

A more common bone of contention is where more people stay than were expected.

"Again, the key is to make clear the number of people you will accommodate at an early stage," he said.

"You also have to make very clear what kind of accommodation you are offering, and be honest about it. If you have four bedrooms but are going to leave one locked with your valuables inside - which we do recommend people do - you have to be upfront about that."

While most people leave home entertainment appliances in situ, it may be wise not to allow access to your personal computer. "Equally, if you are worried about lending your car, just say no and agree to organise rentals," he says.

Don't limit yourself by only looking for house profiles similar to your own. "Very often people, and it is especially true of Americans, are just looking for a well-located base from which to see the sights. Once they know, they don't mind swapping a six-bedroom house with pool for an average three-bedroom semi," says Kelly.

Marie Murphy has been running Homelink Home Exchange in Ireland since 1984, when she heard a radio feature about it and thought it seemed a terrific idea.

Today it has 700 members. Annual subscriptions to Homelink cost €100 and allow you provide your own house details and view others. For €120, you get an entry with photographs. The cost of appearing in its hard copy directory is €145.

"One of the biggest trends in recent years has been the number of people who want to house-swap using their holiday home," says Murphy.

"The number of people who have second homes in Ireland has grown enormously but people do get tired of going back to the same place all the time. This is a way to make use of the second home while staying in another part of the world, for free."

If you are offering a holiday home for swapping you must make this clear to potential swappers.

"People don't want a clinical looking, characterless holiday home. Neither do they want the hovel you inherited in Wexford. It has to be of a high standard and you have to personalise it.

"Small touches such as books and flowers make it feel more like a home, which is what house-swappers are after."

Whether you offer your first or second property for swapping, first make sure it is clean.

"The most important part of organising a house-swap is to make sure your house is clean and tidy. Don't get involved if you're not prepared to clean," says Murphy

A veteran of 15 house-swaps, she hasn't been on one for the past five years.

"My kids are students in their twenties, which means, unfortunately, I haven't had a house to swap. This summer I'm going on holiday in Germany and it's killing me to have to pay for an apartment."

• Intervac.ie

• Homelink.ie

• Guardianhomeexchange.com

• Gumtree.ie

• Homeexchange.com