The Nineties predilection for all things "retro" (particularly from the 1960s and 1970s) has boosted demand and value in modern design. But, while fashion plays a part in the market's success, its novelty value has dwindled in favour of a more serious and informed interest.
Buyers, say dealers, fall into the "young professional" bracket, predominantly under 40, looking for something with investment potential to fill their homes. And although there is a degree of speculation in any new art market, the creation of departments in top auction houses is testament to 20th- century design's staying power, as is continuing improvement in prices.
Bonhams first put modern design in the sale rooms in 1991, and realised pounds 61,000. On Wednesday, it is holding a sale that is estimated to realise pounds 190,000.
The sale focuses on the most innovative design from the latter part of the 20th century, with highlights including Ron Arad's Misfits, 1997, a group of sculptured red felt chairs, and Pierre Paulin's "Tongue Chair", from 1967. Sale prices range from pounds 150 to pounds 16,000, although most estimates are in the hundreds, making the sale affordable to younger buyers. Chairs by Tobias Scarpa are reasonably priced, around pounds 300, while an original 1950s mushroom-shaped Italian desk lamp costs pounds 150 to pounds 200.
The recent creation of Bonhams' Futures department - contemporary ceramics, design and visual arts - has sprung from the success of these sales. "I'd like to think we are supplying quality design that reflects the culture, quality and innovation of the 20th century... which [buyers will subsequently be able to] sell at a profit," claims Alex Payne, head of design at Bonhams. Christie's will hold its sixth modern design sale on 18 March.
But speculators should remember that design fashion is fickle. One year we are encouraged to clutter our living space, the next we have to banish all furniture. A bit of study is needed to make the right choice. Check how rare a piece is, how often one has come up for auction, and at what price pieces have sold. Premium value can be found in objects that are limited edition or unique prototypes.
Items made as recently as the mid-1980s are already commanding higher prices at auction, fetching three or four times the original selling price. Ron Arad's Tree Light, up for sale at Bonhams on Wednesday, was originally priced by Arad at pounds 350 in 1985, but is set to fetch between between pounds 800 to pounds 1,200.
As the demand for 20th century design grows, so books are rapidly being written on the subject. These are good for identifying what you are looking at and discovering which designers are important. Past results from old sales can be requested from sale rooms and clients can consult the resident experts about the scarcity of their chosen items. Once you have decided what price you are prepared to pay, stick to it.
One difficulty for amateur investors is the lack of an index measuring improvements in market value, although Bonhams is introducing a new 24- hour phone service that can access prices realised in sales. Phillips is the only auction house to offer a general survey of all its sales that includes highlights of the previous year and predictions for the next. Sadly, it does not deal in modern design.
As with true antiques, there are plenty of fakes about. Simon Alderson collects and deals in furniture from pre-war to the present day in his Twentieth Century Design gallery in Islington, London. He says: "The biggest problem is that a lot of old furniture is still being made, unlicensed and licensed. Manufacturers are reproducing old designs, many with the permission of the original designers or their estates, but several without."
But he remains optimistic about the value of modern design, insisting that: "Certain styles will go through peaks and troughs but people should not be disillusioned; that is just the infancy of the market. Over the past five years, prices have tripled. Certain designers will undoubtedly reach the peaks of Charles Rennie Mackintosh and William Morris. Look out for Charles and Ray Eames, Verner Panton, Alvar Aalto and George Nelson."
q Bonhams Design sale, 6pm, 25 February, Montpelier Street, London SW7, 0171-393 3900. Bonhams Voice Results Service, 0640 701070. Christie's Modern Design, 2pm, 18 March, 85 Old Brompton Road, London SW7, 0171- 581 7611. Twentieth Century Design, Tuesday-Saturday 11am-7pm, 274 Upper Street, London N1, 0171-288 1996.