It's a tall order for what is usually a smallish bedroom, to take youngsters from baby to toddler, schoolchild to teenager. The room develops from simple nursery through playroom to study-cum-sitting room, as the birthdays roll by. But furniture design moves on apace.

Today parents are prepared to fork out much more substantial sums for furniture which is both remarkably adaptable - and of high quality. Most importantly, it will see junior right through his or her formative years.

Alan White is furniture buyer with the Sterling Furniture Group. ''In the past,'' he explains, ''people would spend only a little on children's furniture, because it would be a one or two year buy. But children's rooms now, tend more to be designed round sofa-sleepers which can be converted to make a sitting room at night for watching tv - and they're designed round computer tables, where they'll do their homework.

''People are buying furniture that children will grow into, rather than grow out of, so they're willing to spend a bit more in the initial purchase.''

Recently returned from a buying trip to the US, White notes that a major concept there in children's furniture, is what they call Rooms to Grow.

Items such as chests of drawers and wardrobes, known in the trade as 'case goods', suit child, teenager or young adult, so that the only thing which ever needs changing, is the bedframe.

''When they're only six, it might be a bunk bed; when they're 12 it's changed to a single, and by the time they're 18, all they need do is change it to a double. The surrounding furniture never needs to be altered - so it's a room-to-grow concept,'' explains White.

Danish manufacturer Stompa, is considered by Sterling to be the market leader in such ranges. Their best selling piece is a sturdily-built Scandinavian pine frame with a central ladder up to the bunk bed on top.

Neatly arranged underneath, is a desk, a shelf and a chair which converts to another bed in seconds.

The price is around #800 - to which you have to add the cost of a mattress for the bunk bed, around #80-85.

When parents are furnishing a whole room, to include wardrobe, chest of drawers and so on, they probably pay #1000-1500.

Another range in the Room to Grow theme, is Gautier which includes a design with a stylish black lacquered finish and some units with smoked glass doors.

Ikea has the Stora, a loft bed with a workstation underneath. Made in Sweden, of pale lacquered softwood this time, it offers beds in three widths. The 140cms by 200cms size - slightly larger than a normal double - costs #395 inclusive of mattress (mattresses are all 2metres long).

A unit for underneath, incorporating a desk with shelf unit with three drawers, is priced at #150.