It's the dream way of getting more space in an existing house isn't it? No foundations, no loss of garden or light from existing rooms - just a quirky room in the roof and a little stair to get there.

Ok, so it's not always that straight forward, and building regulations today can mean there is more of an effect on the rest of the house than in days gone by. However, when it works it works and that extra room can make all the difference to a growing family, a lodger or a home-worker.