In the worst cases it may reveal plans to build a motorway through the living-room. A more common - and less dramatic revelation - is the absence of planning permission for an extension that has already been built. But for most buyers the biggest problem has been getting the search done.
In the late Eighties, when the property market was at its peak, local authority administration keeled over in many boroughs because of the number of searches being requested.
Weeks after all other parties had completed their business, local authorities would finally produce the result of their inquiries.
Solicitors recall seven-month delays on searches in the London borough of Brent, although the council itself considers this an exaggeration.
Such waiting times have declined with the slump in the property market. Camden, for instance, has managed to cut its waiting time to four weeks and Haringey has reduced it to seven days. But solicitors do not believe that protracted delays are gone for ever.
'If the green shoots of recovery assist the property market, the search delays could come back again,' said Leon Lurie of Stamps in Hull.
Dramatically increased charges have accompanied the drop in waiting time, however. They now range from about pounds 40 to more than pounds 100, depending on which borough the property is in. Brian Marson, a solicitor at the Dartford-based Marson Partnership, remembers when all local authorities used to charge about pounds 12. Now, he says, the London local authorities are involved in a seemingly endless spiral of increases.
'We cannot just lie back and accept the London boroughs leap-frogging each other on fees. We're paying twice as much as two years ago,' he said. Charges of pounds 150 or pounds 200 within the next year or two are not impossible, he thinks.
Boroughs are increasingly trying to make such services pay for themselves and perhaps for a little extra. Whether the house-buying public gets value for money is less of an issue for them.
Camden charges pounds 100 for the service and is the most expensive borough in London. The others are not that far behind: Wandsworth charges pounds 89 and Haringey charges pounds 85.50.
Even a search that reveals nothing untoward does not mean that a home buyer can sleep peacefully. It may also be a good idea to check that the local water, gas or electricity company does not have cables or pipes that run underneath the property. If so, they have a right to maintain them: Thames Water, for instance, is in the process of digging up a number of back gardens in Reading.
There can also be problems if the water supply to a property does not travel through public land. The danger that neighbours might tap water from your supply matters little at present, but will become more important once water metering is more fully implemented and you have to pay for what comes from your supply.
Not even all these searches can fully protect the home buyer. For instance, in Devon and Cornwall, many of the tin mines were sunk before property records began. Householders have sometimes found holes appearing in their back gardens, revealing a mine, unbeknown to the local authority, underneath.
Royal Insurance offers a specialist insurance policy to the house buyers who needs to complete a purchase before the local authority search is finished. The premium is pounds 50 for most properties.