THERE are 14 shops on the two sides of Upper Richmond Road where it intersects Putney High Street in southwest London, but not one of them sells bread, milk or even underwear. That’s because all but one are estate agents — this spot may have the densest concentration of them in Britain.

Andrew Charalambous, who works at the shoe repairer Cobblers of Putney, the only shop in that stretch that is not in the property business, said: “When I came here in 1992, there were eight estate agents. Now there are 13. Luckily for me, many of them are good customers.”

Estate agents have become numerous — if not quite to that extreme — in most parts of Britain. In Cupar, a small market town in Fife, 10 miles west of St Andrews, house prices rose more sharply than anywhere else in the year to the end of April — by 36% — and there are now half a dozen estate agents on the main street.

Martin Paterson, the manager at Pagan Osborne, a long-established local agency, said: “There has certainly been a great increase in the number of estate agents. People have come in from outside without necessarily having the knowledge of the area. I don’t think there is room for more.”

The profession that people loved to hate in the 1980s is now more economically important than ever: according to the Office for National Statistics, in March property agencies employed 134,000 people, including negotiators, support staff and 13,000 surveyors. This total outnumbers British Army soldiers (100,620) and postmen and postwomen (105,000).

Their rate of growth has been just as striking. The number of people employed in “real-estate activities on a fee/contract basis” (which includes estate agents and people managing properties for others) has jumped 72% in 10 years.

Estate agency has grown for one simple reason — revenues have trebled on the back of the surge in house prices.

The value of housing transactions in England and Wales, estimated from Land Registry figures, rose from £70 billion in 1996 to a peak of £221 billion in 2004. It then fell to £195 billion last year as the number of transactions dropped, but is on course to hit £225 billion in 2006, if the first quarter’s 11% rebound in transactions and a 4% rise in average prices lasts through the year.

Key Note, an independent consultancy, estimates that 90% of sales go through agents, and commissions average about 1.5% of the selling price. It reckons agents’ income (including contributions from lettings and financial products) shot up from £1.7 billion in 1996 to £5.7 billion in 2004 and 2005.

However, if someone were to do a “surveyor’s report” on the industry, the conclusion might be that this is an edifice that has suffered from subsidence in the past — particularly in the housing slump of the early 1990s — and that, once again, there are a few cracks visible. There are three main dangers now: overexpansion, cut-price competition and increasing regulation.

Over-expansion is a perennial hazard in the sector because of its sensitivity to the economic cycle, and the ease with which new competitors can enter the market.

Jeremy Leaf at the Royal Institution of Chartered Surveyors (RICS) said: “The cake has got bigger in estate agency as a result of the sharp increase in house prices over recent years. But we think overstretch is very much a danger.”

Harry Hill, group managing director of Countrywide, Britain’s largest estate-agency chain, said: “Not only are there too many agents in the UK, but most are working for little money. When the market is bad, it’s a thin living.”