Sharing an apartment, particularly with strangers, can be a risky business. With only around 600 to 900 sq ft to play with in most two or three-bedroom apartments, there are few places to hide if things go horribly and irretrievably wrong.

Most people who have rented over a long period will have some grisly tale of flatmate hell to impart, and the more confined the area shared, the more intense and traumatic domestic strife can seem.

`It's like living in a bubble," says psychologist and psychoanalyst Domhnall Casey. "An apartment is often too small to escape anywhere. Everyone needs a bolt-hole - and in an apartment you often don't have a place to regain perspective, which can heighten and exacerbate any problems which may arise."

Conflict often occurs, says Casey, because each party brings the baggage of their previous domestic experiences with them. "People have different ways of doing things and sometimes there might be one dominant person who tries to impose their will on the others. If there is an even number of flatmates, they may split into two equal halves. If there is an odd number, however, there is a greater possibility of bullying and scapegoating."

Often the key to harmony in a small space is a recognition of the need for some regulation and order, but even this can backfire. "Irish people often don't like too many rules. One person may take it upon themselves to impose some order, but in doing so, they are setting themselves up as the mammy or the conscience of the group. They may be seen as priggish and find themselves shunned by the other inhabitants."

Celebrity Big Brother was a fascinating insight into the dynamics of bringing six very different people into a confined space. The contestants had nowhere to run - as comedian Jack Dee discovered after several botched attempts at freedom.

Vanessa Feltz initially appeared strong and quickly established herself as the earth mother of the group, but felt betrayed and under siege when nominated for eviction by her fellow contestants and the general public.

Feltz can recover her sanity and dignity, after her furious blackboard antics, in the safety and comfort of her own luxury home. In the real world, however, with rents averaging £1,000 to £1,200 (€1,269E1,523) per month in Dublin for a decent apartment, sharing with people you don't know is often the only option.

As accommodation-sharing can be fraught with potential difficulties, most letting agents steer well clear. The small ads are a more usual way of finding a flatmate.

Two female friends of mine recently advertised in the classifieds for a third person to share their apartment, conducting interrogations in Bewleys in Dublin's Westmoreland Street. While they sat on one side of a table, hapless respondents squirmed nervously on the other.

One played the smiling good cop, while the other probed into background details and personal habits. Bonus points were awarded to anyone who could fix a plug or dabble with a fuse box and those with unrealistic expectations - watching football for prolonged periods for instance - were soon put straight.

Eventually, after an exhaustive search, they found the perfect flatmate: a quiet guy who sits through countless soaps, goes home every weekend, makes tea - unprompted - and puts the bins out when instructed.

All this might appear a little tyrannical, but bitter past experience meant these two left nothing to chance.

Joanne e-mailed Apartment Living about flat-sharing in her final year of college. An Irish girl, she lived with three other girls, but remains firm friends with just two of them - an American and an Italian. The other girl, also Irish, was "very very strange".

"This manifested itself in small ways, such as studying in her room with the door locked, keeping her own plate, cutlery and cup in a locked cupboard, and generally isolating herself from us in many ways. She never, never cleaned up after herself and only spoke to us to tell us horrific stories about her family and childhood."

Joanne also spent a year in NUI Galway doing a postgraduate diploma during which she shared a flat with four girls, all Irish, except one.

"Again, the Irish girls were sloppy, inconsiderate and didn't lift a finger in the flat. One of them played loud music so often that I got tired of asking her to keep the noise down and moved out, with three months to go before the end of the year, losing money in the process."

Gabriel rented his spare room to a student who "wasn't on the same planet as the rest of us". The catalogue of mishaps "is now amusing to recount to friends" but was far from funny at the time. "In the space of a few months, he managed to blow the iron, set fire to the grill and leave a pot on a hot ring of the cooker. He let the bath overflow which leaked down to the hall ceiling below.

"On one, occasion he ran from the bathroom to answer the phone, and left the handset smothered in shaving foam."

Comedian and TV host Dara O'Briain said sharing a pad in London with fellow comedian Ed Byrne is not as funny as it sounds. "It's not all a barrel of laughs, we just sat in watching videos." Still, sometimes it can be a case of better the devil you know. "Strangers are bad," quips O'Briain, recounting the time he and his friends shared with a guy who "would go to the early house straight after work and arrive in at 9 a.m. every morning pissed as a fart as we were heading off to work". Then there was the time a couple did a runner, owing rent."

Mutual respect for privacy and knowing when to back off when confrontations arise is important when sharing an apartment.

Ground rules should be established from the beginning and each party should discuss their expectations of the group. It's a good idea to meet up in a social setting before committing yourself to anything.

And while all this may seem to be seriously lacking in spontaneity, it certainly should be remembered - as you will be spending a lot of time with these people. It can help if your home's atmosphere is more akin to that of Friends than of Single White Female.

emorgan@irish-times.ie