House Doctor: 'How do we stop being gazundered by these scoundrels?'

Question: We've just been gazundered for the third time in four months, and are getting sick of politely telling buyers to get lost. Can we do anything to stop it happening? Buyers say, 'Why should I pay for something that's going to be worth thousands less in a month?' Joyce Green, Powys

Answer: It's the telephone call that sellers are learning to dread: just hours from exchanging contracts, the buyer rings to ask for a price reduction or they'll walk away.

This last-minute threat, known as gazundering, has been witnessed with growing alarm by the National Association of Estate Agents. It recently warned that in some parts of the UK, such as south-west London, half of all sales – from one bed-flats to detached homes – are affected.

It's hard to counteract when, as you've discovered, potential buyers throw evidence of falling prices in your face: only last week, figures from the Nationwide building society suggested average property prices had slumped by 12.4 per cent in the past 12 months.

"The awful truth is that you're selling an asset – your house – that's simply falling in value," says Katie Tucker at the broker Mortgage Force. "You could try to get back this 'money off' when you come to buy your next property, but if you're in a chain, it can often jeopardise the whole process."

Three gazunders in four months is extremely unlucky, says Melanie Bien at Savills Private Finance, but there are steps you can take to lower the risk.

"Getting the right price to start with is essential; we're advising sellers to set an asking price 25 per cent less than they would have expected to get a year ago if they want to sell right now."

At the very least, make sure you're factoring in some sort of price reduction to reflect the falling market – this way, she says, "potential buyers have less of an argument for dropping their price".

Another defence to try, says David Hollingworth at broker London & Country, is to point out that while prices may well be heading down, the buyer is doing a deal today.

"Buyers are paying the price for the property now, not in a few months' time – if it were a rising market they'd hardly be offering to pay what the property might be worth in the months to come."

He adds, however, if you're in a chain, try a radical escape route if it happens again: ask your estate agent if the financial shortfall you face can be spread throughout the chain instead; ie convince all the parties to take on a share of the gazunder.

"With the collapse of a chain potentially costing all parties money in wasted survey fees and legal costs, you could find they may be prepared to spread the burden to secure the sale."

If you do end up accepting a lower offer, take control by insisting that certain conditions are attached, says Bien: "Request the survey to be done within a week to ensure that they're committed to the purchase."