Overview: Buyers must double-check the details when buying a home off-plan

The idea of signing on the dotted line for a home that is nothing more than a drawing now holds few fears for buyers.

The idea of signing on the dotted line for a home that is nothing more than a drawing now holds few fears for buyers. Over the past few years, the property any buyer eventually moved into would, with few exceptions, have increased in value. But the fact that selling from plan is now commonplace up and down the country does not mean that buyers should lower their guards.

Only last week, developers Persimmon pleaded guilty to four counts of misdescribing flats at their Icon development on the Isle of Dogs. A couple who had bought a £290,000 flat found that, on measuring the end result, the floor space was 10 per cent smaller than they had paid for. Other residents also found themselves short-changed - by as much as the size of a double bedroom.

The issue was clear here, but there are those grey areas where buyers feel badly done by but have no precise measurements on which to base their complaint. It was only a few months ago that Persimmon received another dose of bad publicity when a couple complained bitterly that their car barely scraped into their new garage.

What this goes to show is that it pays never to take on trust what should be in writing and that final checks on a thing as basic as room sizes should be done as a matter of course. Many agents who work in the area of new developments will suggest a purchaser employs their own surveyor, even if it appears to contradict the purpose of buying new.

It is not helped that at the launch of some schemes normally sensible people find themselves caught up in a buying fever. Teams of solicitors and financial advisers make it easy to exchange there and then.

Linda Beaney, of London estate agents Beaney Pearce, has long held concerns about how ill-prepared some buyers are. Her firm produces a guide on the advantages and disadvantages of buying from plan and how best to proceed.

Appointing a surveyor and a solicitor familiar with the process are crucial. "I have seen specifications so vague they are not worth the paper they are printed on," she says. "A detailed specification annexed to the contract for purchase would cover everything from the height of skirting boards to the kitchen appliances. But it might take a brave person to insist on it because they stand a chance of losing the property."

Nor is it just a matter of checking whether the doors are the same as those in the artist's impression (an omission for which Berkeley Homes was fined last year). They must also ensure that the overall quality of the finished home meets the original specifications. If a surveyor decides a property fails to come up to the standards, a sum of money can be retained until the work is completed.

There are other clues as to how much credence can be given to a brochure. A development that is advertised as being within a short walk of a place that cannot be reached in less than half an hour might reasonably come under suspicion.

Not all purchasers will get out the tape measure before taking possession of their home, however. Among the large numbers of buy-to-let investors, some of them buying in bulk, there will be those who have taken their eye off the ball when it comes to checking on every detail.

It will be a shock to know that it is possible to get 10 per cent less than you paid for.