The most sought-after room-mate A "Professional female, non- smoker" is the most sought-after room-mate in the accommodation-sharing columns of classified advertisements.

As rents for city centre properties rise, sharing accommodation is becoming more popular among twentysomethings and "roommates" are in vogue thanks to popular American sitcom Friends, and UK drama This Life.

A word of caution: accommodation sharing does involve more than simply renting out an extra bedroom to someone who appears to be an amicable stranger.

Accommodation sharing is described by many estate agents and property lettings companies as a "murky and messy" business, and is not among the range of services they offer to landlords and tenants.

Sharing accommodation, by all accounts, involves quite a number of risks, but, with rents at a premium, many owner-occupiers and tenants have limited choices.

Personalities, professions, personal habits, likes and dislikes - accommodation sharing is where rational and irrational factors come into play.

As rents have spiralled in the last year, shared accommodation is becoming a practical option for young professionals. Two-bedroom apartments in the city centre are now fetching £850 to £1,000 per month, with prices for one-beds starting at £700. A room in a shared house ranges from £250 to £350 per month.

A quick scan of the classifieds will confirm that professional females in their mid-20s are the most popular group. There is a general perception of females as cleaner, tidier and quieter than their male counterparts - or it just may be that females don't watch the soccer premiership for hours, swilling beer.

"Professional 25-35 yr old with a sense of humour" and "Quiet, tidy, pleasant non-smoker 9-5 job" are also among some of the requirements in the accommodation-sharing adverts.

It is not uncommon for an advert for a double or twin room to say it would "suit 2 girls", and the price will usually reflect this.

While estate agents and property lettings companies shy away from this side of the lettings market, Roommates is a specialised service that matches accommodation seekers with people who have rooms to rent.

This accommodation sharing agency service was established two years ago by Margaret O'Grady, and has placed hundreds of people via the Internet and phone.

"I consider myself an intermediary, matching people looking for accommodation with people who have it. I provide advice for both parties, and stress the importance of laying down ground rules upfront; this makes things easier in the long-run," says Margaret .

This service is an alternative to the classifieds and offers more security to landlords and tenants.

For tenants, the main factor in the search for a room to rent is usually the location, and the proximity of the accommodation to transport and amenities. Just like house-hunting, searching, and then interviewing, for a room in a house or apartment can be a tiresome process for both the present occupants and prospective tenants.

Ann Brady, a computer programmer, found that it took her three weeks to secure a room. "I was making 10 to 15 phone calls a day, going to see two or three different places at night, and answering the same questions about myself over and over."

While the services of an agency can make the searching process easier, visiting the properties and meeting the present occupants cannot be avoided.

"As well as being very tiresome, it was nerve-racking. You only have a few minutes to see if you like the people, and if they like you, and whether you would get on sharing such a small space together," says Ann, who eventually found a room in a three-bedroom apartment.

Twenty-seven-year-old James McGowan, who has been looking for accommodation for a few weeks, believes that shared accommodation is a very convenient option for young people. "As prices rise, it is becoming tougher to find accommodation in Dublin. I'm looking in the Ranelagh/Rathmines/Harold's Cross area of the city and there just seems to be huge demand.

"Properties are advertised in the newspapers with viewing starting at 6 p.m., and if you get there at 6.10 p.m. you'll find that it's already gone! When it comes to finding a room in a shared house, then personality is what's important. You have to look at common interests, social habits and working schedules."

Roommates agency vets prospective clients, asking them to fill out personal forms and to provide bank and employer references. This does provide an element of security to the occupants of the house, especially in cases where household bills have been left unpaid.

The owner-occupier or occupants give their specifications to the agency, saying whether they would prefer a male or female, student or professional, smoker or non-smoker.

Ann Brady shares her city-centre apartment with two other women. Initially, she found that the first few days were intimidating - "I was, after all, living with strangers" - but she has since settled in well and feels very comfortable with this new living arrangement.

Respect is the key to accommodation sharing harmony, and Ann believes that strangers living together do tend to respect each other's privacy more than family or friends. "We all have our own individual lives, and the relationship works well on that level," she says.

WITH Roommates, the accommodation seeker pays a once-off fee of £30 to the agency, and then has access to their database of accommodation until such time as they find a room they are satisfied with.

This database can be accessed via the Internet, and is updated twice daily. Alternatively, for those without Internet or e-mail access, you can also receive the list by fax, and consult with Roommates by telephone.

Margaret O'Grady does stress that people should be extremely cautious and should ask their new room-mate for bank or employer references. It provides an element of security in the event of future trouble.

Eircom provides itemised bills so that each member of the house can identify their personal calls, but other utility bills such as heating, lighting and gas will have to be divided equally.

It is also important to establish ground-rules for the house before the new tenant moves in. This should save you from having a nightmare tale of your ex-roommate to tell.

Roommates can be contacted at 01 6214146, www.roommates.ie