More than one million pounds. That is the startling price that just one acre of city centre land can now command in boomtown York.

Yuppies' growing demand for flats in the heart of the city is sending land values soaring.

Young affluent couples and singles want the convenience and security of city living - and are prepared to pay for it.

"Demand for flats has increased dramatically in the last few years," said York chartered surveyor and valuer Alan Black.

"There always used to be a stigma attached to them. But now people like the convenience and security of them. They can lock them up and go away on holiday without worrying about the garden."

He said city centre land where the conditions were right for flats development - including planning permission - was fetching well in excess of a million pounds for an acre.

John Urwin, property consultant with City of York Council, said land values in the centre of York had more than doubled in the past five years.

And he said it was rumoured that one city centre site measuring less than an acre and where high-density flats were planned - the NCP car park in Skeldergate - had fetched at least £5 million.

Philip Roebuck, of property advisers DTZ Debenham Tie Leung, which handled the sale of the NCP site, agreed that an acre of land could command in excess of £1 million, if the conditions were right for high-density development.

"The value is driven by the density of the development."

He was unable to reveal the price the NCP site fetched, saying it had been a private treaty sale, but confirmed: "It did attract an awful lot of interest."

The boom comes as the Government is demanding more "brownfield" residential re-development to meet future housing needs, in order to protect the countryside from urban sprawl.

Mr Urwin said that residential brownfield land in the centre was fetching between £1 million and £2.5 million. That compared with £500,000 to £750,000 per acre for suburban greenfield sites as a two-tier market develops.

"Anyone with city centre land with residential planning permission is sitting on a fortune," he added.

He said the high values reflected the large numbers of flats which could be built on a single acre of land.

York planners will consider over coming months how much brownfield development can take place as they set future boundaries for the city's green belt.

House prices are rising faster than at any time since the boom of the 1980s, according to Yorkshire's estate agents.

But the rise is expected to slow this year.

Mike Skelton, the Yorkshire chairman of the National Association of Estate Agents, said: "Demand presently exceeds supply. Prices are increasing at the highest rate in the area since the property boom of the 80s."

But a spokesman for the association said: "The second half of 2001 is set to see a slower and steadier rise in house prices than the first six months."

Updated: 11:42 Monday, June 18, 2001