Property: Fancy living in a water tower?

It used to be barns, windmills, oast-houses and even churches. Characterful as these conversions can be, they are no longer extraordinary, and those searching for a property that stands out from the rest are now casting even wider in their search for the novel. Nor is the quest restricted to an adventurous few.

The concept is now widespread with the increasing popularity of warehouse conversions, and typical developments, such as the newly converted Tanners Yard in Bermondsey, where apartments built around a courtyard in a former leather and tanning works, embody its key features, says James Struth of estate agents FPD Savills. "A combination of characterful historical connections, with attractive architecture and unusual original features, all used in a sympathetic conversion, has become highly seductive for a large number of today's buyers. Wise investors too are realising the need to invest in properties that are in some way special and stick out from the crowd, and should appreciate over time due to their rarity," he adds.

But, for many buyers nothing less than a one-off - or almost one-off - will do. As luck would have it, there is a steady supply of such properties, with origins both humble and grand, now finding their way on to the property market. Some have already been given a slick overhaul by a developer, others transformed by an enthusiastic previous owner, while some are in such a condition that only those with a vivid imagination could visualise them as a covetable "des res".

As well as old industrial buildings, there are plenty of properties with a past financial or legal role, whose occupants have moved to modern premises. A one-time London bank with many original features - including a very grand banking hall, complete with polished mahogany pannelling - is for sale as one, sizeable unit, via London estate agents Marsh and Parsons. A former magistrates court in Clapham, now converted into a home, is being marketed by FPD Savills. It still has the old court room, with its nameplate. Such a property, restored to pristine condition, does not come cheap, especially London. The bank is pounds 1.4m and the courthouse about pounds 1.5m.

For those with vision and love of a challenge, the ever-changing urban environment can throw up even more unusual properties from unpromising sources. When Nick Allen was looking for space for his ceramics business he found a utilitarian-looking office building on the site of a former umbrella factory in Battersea, south London. After obtaining planning permission to use it for both residential and commercial purposes, he renovated it. The original features he was left with included concrete and hundreds of yards of musty brown cord matting, rather than marble and wood pannelling. But he too has transformed the building into something unique that bears his own personal stamp.

Michael Holmes, editor of Plotfinder which lists properties in need of renovation for sale is rarely surprised at the apparently unlikely buildings or objects that are turned into homes. "In one case a former reservoir tank was transformed into a residential property, and in another, a one-time grain silo was converted and became a home", he reports.

Among the more unusual conversions currently on the market is a former hospital water tower, now a six-floor, four-bedroomed house at Repton Park in Essex, that is being marketed by Crest Homes. For the more rural- minded a rare converted dovecote with original stone nesting boxes is for sale at pounds 310,000 in Gloucestershire, through Lane Fox.

Former "follies", can also provide a happy hunting ground, and are not only found on remote country estates. The Gazebo, a Grade II listed building, is a folly that has been converted into a three-storey dwelling - and is located close to Richmond town centre.

A key issue, however, for those after the unusual, quirky, or downright eccentric, is the question of how lenders view such properties. Celia Rowland, of the Halifax, says: "The key is saleability in the future. You may think buying a shop in a parade of other shops that you will convert into a house is a fun, individualistic thing to do, but as lenders we will be interested in what will happen in the future, and how the market is likely to view your property when you decide to move".

For those whose dream house is still no more than a shell, Ms Rowland says that lenders will need to know fully about exactly what is planned, and how feasible those plans are from a practical point of view, and in relation to issues such as planning permission and building regulations. "One crucial area is the sort of materials that the property is built from, or which will be used, because that has important implications for insurance purposes in relation to the mortgage."

But how do you price a one-off? "It is all about specialist lending, and some of these properties are very niche, but ultimately it is about looking realistically at values," she adds. That can be a problem for both buyers and sellers. "It can be difficult to price a property when it really is unique," says Sarah Jones of Crest Homes. "In the case of the converted former watertower, because of that problem we are going to come up with some price guidelines, and go to sealed bids." It is all part of the price you pay for daring to be different.

`Homebuilding and Renovating' magazine, 01527 834400