'Good' addresses are expanding while 'less good' ones are contracting, says Edel Morgan

Some call it living in denial whereas others prefer to see it as creative visualisation. This is when people visualise they live in a more upmarket area nearby and then slowly start to believe it. They might borrow a more desirable post code even if it's just while they sell their house.

It seems that a lot of people are doing it and, if they're not, estate agents are doing it for them. The end result is that most of us deep down know the true location of our neighbourhood but play along with the charade as it's easier all around. Bringing your neighbours down a peg or two with the truth is a dangerous ploy. Reminding them they live in Ballymun not Glasnevin or Deansgrange not Foxrock can have you frozen out of residents association meetings before you can say "social leper".

A few weeks ago I rang Walkinstown postal sorting office to find out the address and post code of Manor Estate. We had received a phone call from a lady who was baffled at the addresses and post codes attributed to it by four estate agents selling properties there.

She believed it was located between Walkinstown and Templeogue in Dublin 12 but two estate agents put the address as Terenure, Dublin 12 and another two as Terenure, Dublin 6W.The guy at Walkinstown postal sorting office told me "some people who live in Manor Estate like to believe they live in Terenure but Terenure is Dublin 6W". A more correct address, apparently, would be Greenhills or Walkinstown, Dublin 12. So if a house in Manor Estate is advertised as Terenure - but is really Greenhills - does that mean that the person who buys it will actually believe they are living in Terenure? Or will they know the truth and just choose to buy into the neighbourhood conspiracy? And will pretending you live in Terenure make a whit of difference to the value of their house? When I presented this conundrum to a colleague she replied enigmatically: "Perception is reality."

Estate agent Ronan O'Driscoll from HOK points to the example of Rathfarnham "which started out as a small area and now encompasses giant swathes of the southside. Blackrock used to be a main street but now stretches to Deansgrange", which, in turn, has become part of Foxrock. Areas with flexi-addresses tend to be situated "on the fringes between one area and another" like between Swords and Malahide, Lucan and Clondalkin, Sutton and Baldoyle, with the "good" areas expanding and the ones perceived as "less good" receding . But does pretending to live in another area have an effect on property prices? "Over time, yes," says Ronan O'Driscoll. "If you decide you live in another area today, it won't." He points out there is a difference between pretending and "misdescribing". "There is no line on any map to say where one area ends and another begins but there are definite postal districts."

Alarmingly, changing the name of a property can alter perception. A number of years ago a well known builder lived on the less popular north-facing side of a salubrious residential road. He remedied the problem by calling his house "Sunnyside".

Powerful marketing can even obliterate a location. A whole section of the Stillorgan Road (once an Esso station) has been supplanted in the public consciousness as "The Grange". The huge advertising billboards outside the residential development showing a woman eating asparagus and people generally being sophisticated have had a huge impact.

There are also ways and means of dealing with "problematic" areas and post codes - just leave them out altogether. It's happening wholesale on property brochures and advertising. I came across a house in Oakwood which simply had the address Glasnevin but no post code. Could it be that, if they put Dublin 11, as opposed to Dublin 9 (Glasnevin proper), it would give the game away? An apartment in the Premier Square development is referred to as Dublin 11, with no mention of Finglas. Similarly, Foster Terrace is in Dublin 3 not Ballybough.

Some even resort to improving a development by borrowing the facilities of the estate next door. Last week a reader phoned to say a six-bedroom house in Meadowfield in Sandyford was being advertised as being part of Kilgobbin Wood. "Kilgobbin Wood is a separate estate and they've used a picture of the parkland facility attached to it in the brochure ," said the caller. When I checked the brochure it cruelly teased potential buyers by telling them the house is "adjacent to nearby parkland available to neighbouring residents".

So what would happen if clear boundaries were drawn between areas and it became illegal to be creative about your address? Would it affect property prices? "I would say it would have a marginal negative impact if people were forced to say where they live, " says Ronan O'Driscoll.

• The correct email address for balcony designer Deirdre Whelan featured in last week's column is deirdremwhelan@eircom.net