“There was only one hitch,” says Nigel Parsons. “We found a gang of local teenagers. It wasn’t anything big, just the usual mindless stuff.”

But it was enough to make the buyer think again. Parsons runs a detective agency that does all the usual things that detective agencies do: investigating corporate fraud, recovering debts and sitting in parked cars in darkened streets to see if husbands are cheating on their suspicious wives.

But for a fee of £325, the Answers Investigation agency will also snoop around any area in which you are thinking of buying a house. “It wasn’t difficult to spot this gang,” says Parsons. “We saw them in action: about a dozen of them throwing logs onto somebody’s garage roof. And as soon we got talking to people in the area, we discovered this wasn’t that unusual.”

If you chat to any estate agent for more than five minutes, they will trot out the line that most homes are sold within the first two minutes of a viewing. First impressions are very important. But a first impression will not reveal whether the neighbours run a car repair business or are devotees of thrash metal music. “Noise is a big issue,” says Parsons.

The house detectives begin their search by computer, looking for information about the area on the internet and in their news cuttings services. They have access to local crime statistics, and residential listings that reveal whether there is a high turnover of homes in the area — usually a bad sign. Then they slip into their overcoats and trilbys — figuratively, you understand — and head into the area for a wander.

“We take a look at the area and talk to as many people as we can,” says Parsons.

A member of the agency recently visited Streatham in south London, and met with comments such as:

“My mates always get their trainers nicked.”

“The transport round here is rubbish.”

“The railway station smells.”

All this goes down in the detective’s report, without comment.

You might think that a buyer, armed with the knowledge that the railway station is smelly and that trainers are routinely stolen, would decide that Streatham is not their dream location. But buyers are apparently more robust. Parsons recalls: “On one search we did we discovered that a chap in the same road worked in a medical research laboratory and was subjected to frequent demonstrations by the Animal Liberation Front. But the buyer didn’t seem to mind.”

Explore Property

• Buying & Selling

• New Homes

• Overseas

• Interiors

• Investment

• Gardens

• Cool In Your Code

• Specials

Times recommends

• Analysis: frustration for everyone - except investors
• Spanish property: why it's crunch time on the Costa del Sol
• Buy-to-let: professional investors cash in on the credit crunch