the 'Waitrose effect' can boost house values by up to 50 per cent, according to a national estate agent.

But agents in Teignmouth – which is to get a Waitrose – are not so sure it would make that much difference. they admit it will make the town more desirable, when the upmarket supermarket takes over the larger Coop store early next year.

According to research by Savills, having a Waitrose branch in a town can increase values, compared with nearby areas without the brand. The most extreme situation was in London where it could add an astonish 50.3 per cent to average prices.

'Our analysis identifies a very clear house price premium in Waitrose store locations,' said Sophie Chick, a research analyst at Savills. 'It is difficult to state with certainty that a Waitrose opening will boost prices. But it is clear that buyers should expect to pay significantly more for their home if they wish to have a store on their doorstep.'

She admitted there was 'no real answer' to whether Waitrose 'gentrifies' areas, or if the chain opens only in areas which are already upmarket, and so more expensive.

'There's been a lot of anecdotal talk from estate agents commenting on increased demand and interests following the news that a Waitrose is opening in an area,' said Nigel Keen, Waitrose director of development. Ian Bradberry, an estate agents in Oundle, Northants, says he has definitely seen the Waitrose effect in the town where a branch opened recently. 'There has definitely been more interest in properties around where it is located. We do expect that in time this will result in an increase in prices.'

Harry Wallop, author of Consumer: How Shopping Fed the Class System, declared: 'There is a body of consumers who would love to have a Waitrose on their doorstep. There is this snobbishness where people are prepared to man the barricades against a Tesco, but if it's a Waitrose, a fair number of them will change their mind.'

Mel Gore, of Dart & Partners, Teignmouth, said: 'Whether a Waitrose will make any difference to prices remains to be seen. But it will certainly have a positive effect on the town, along with the other regeneration. 'It is another big plus for Teignmouth to add to the new Morrisons store, and the excellent transport links, and it will help to encourage more people to shop in the town, with so much choice.'

James Carden, from Bradleys estate agent, believed it would attract better-off home hunters. 'That is especially so if they come from the south east, where there are many Waitrose stores. They are used to the chain and if there is one in Teignmouth, it could make the difference between buying here or not,' he said. 'Teignmouth is on the up anyway, and has an exciting future. Commercially the town is doing well with several top brands here. And how many other towns of this size have four banks?

'It is not just a seaside resort, but has many other things going for it, and attracts reasonably well off commuters who work in Exeter. But whether Waitrose will increase prices, only time will tell.'

Helen Potts, of Chamberlains estate agent, agreed there was no way of telling yet about the Waitrose effect. 'But it will certainly be a big plus for many people. We have just sold a house to a young professional couple, who work in Exeter and had not really thought about Teignmouth until they came here and liked what they saw.

'They are in easy reach of the station for commuting, and thought there was plenty going on to attract younger working people.'