They are popping up all over the suburban landscape. One day, there is a single house with a generous side garden. The next day, there's scaffolding, and men drinking tea from chipped mugs. And the day after that, there's a whole new house squeezed into the place where there used to be a nice herbaceous border and a basketball hoop for the kids.
It used to be that the biggest job done to a house was to put in double-glazing. That required a re-mortgage and prayers that interest rates would not reach double figures. After that, the extension became the big thing. And it still is for most people, as they spend three months living in one room of the house while chasing builders and watching as the gales whip in through the rubble of what was the sitting room. But it's all worth it for the chance to have an extra four square foot added to the kitchen.
But the really big thing now is to give your house a clone. Anyone with a side garden bigger than the width of a wheelie bin has realised that there is gold in them there hills - or at least, in them there patches of daffodils.
So, in every housing estate across the land, the people on the corner of each road are throwing up a house were you wouldn't think a house could fit. It is the latest manifestation of that incorrigible urge in Irish people to do something with their land. Even if their entire domain consists only of a twelfth of an acre in a place where the rolling parkland long ago gave way to poured concrete. Who needs foreign property when you can build a property that is literally within touching distance of your en suite window.
Sometimes, the house is used to give one of the kids a chance to get on the property ladder. Which means that anyone marrying into such an arrangement must seriously weigh up the pros and cons between getting a decent house at a very decent cost, and living so close to the mother-in-law that you can hear her false teeth rattle as they are dropped into a glass each night.
These house are often built to be rented out, or sold off. Apart from the cash that such an enterprise can earn a family, it has the added power of driving the neighbours completely insane with jealousy. Remember, those neighbours are the people who, 30 years ago, bought into this new estate, except that they turned up at the estate agents five minutes too late to buy the house with the side garden. Or worse, they decided against buying the house with extra big garden. So that every time they walk past the growing building site, the husband gets a nagging reminder. "That giant side garden could have been ours. But oh no, somebody thought there'd be too much trouble in cutting all that grass."