Will a swimming pool add value to your house?

To dive into your own swimming pool when the temperature is soaring into the eighties might seem a splendid idea. However, adding to the 160,000 or so private pools in this country comes at some cost - particularly when you bear in mind that putting in a pool could actually detract from the value of your home.

"There is no doubt that swimming pools, especially outdoor ones, may not add their cost to the value of a property. Sometimes they are a positive liability" says Paul Greenwood of Stacks, the property search company. "This is mainly because they are expensive to run and tiresome to maintain."

People with small children often consider pools to be a positive danger zone. "I have known a number of people fill in very good quality swimming pools after buying a property" says Andrew Dewar of Curchods, an agent in Surrey - where there are probably more private swimming pools than anywhere else in the country.

The positioning of a pool is important. Disturbance is a big consideration. If outdoors, the pool should be well screened and not too close to the house. If you're in the living room, for example, you probably won't want to be regaled by the merry sounds of splashing from other family members.

Indoor pools are, of course, less problematic when it comes to noise. Howard and Christine Beesley have had few causes of complaint with theirs. They were adamant that they should have a full-size (45ft) indoor pool when they built their eight-bedroom house in St George's Hill, Weybridge, Surrey, six years ago. In their basement they duly constructed a pool that opens out on to a patio, with steps up to the main garden.

"We had a pool in our previous house," says Mrs Beesley "and my husband is a very keen swimmer. Indeed we both swim every day. We think our pool is absolutely marvellous and wouldn't dream of owning a house without one".

Yet finding another house with a pool as well sited as their current one might prove difficult. The Beesleys are on the move and their house is on the market through Curchods.

Next on the list of detractions is the space problem. With outdoor pools, if the garden is too small, the pool will hog most of the space - and this will affect the property's value. If the pool is put in the basement, which most are, it could take away so much living space that it would make the house difficult to sell. One developer, Northacre, took the novel solution when converting a pounds 7m house in Chelsea by putting the swimming pool, plus billiards room, under the garden.

However, houses with large grounds and pools do attract more interest, especially in the summer. Dixon Porter is selling - for offers over pounds 1m - a detached family house in Roehampton, London SW15, which has a splendid indoor swimming pool on the ground floor. This has a domed roof-light at one end and two sets of double doors leading out into the garden.

A good indoor pool (it is not worth putting in a cheap one) will set you back at least pounds 10,000 and a very glamorous one could cost up to pounds 100,000. "Indoor pools, although expensive, can add appreciably to the value of a property" says Mr Greenwood, "because they can be used all the year round. But they must be well designed - certainly if ventilation is poor you will suffer from condensation and quite often an unpleasant smell."

Hamptons' Martin Chester, who covers the Thames Valley, says: "We are more likely to have applicants specifying that they do not want swimming pools. Although some insist on an indoor pool or the scope to create one". Hamptons, with joint agents Chestertons, is selling a six-bedroom house in Maidenhead, Berkshire with a huge, kidney-shaped indoor pool, for pounds 975,000.

Any kind of indoor pool will need planning consent, although outdoor pools, or those housed in a separate building, do not necessarily require consent. And whether or not you need consent, advice should always be sought from your installer or local planning office before the first sod is turned. The latter is another consideration to bear in mind. Not only is it expensive to remove tons of earth, if you live in a town house it could well have to be ferried right through your home.

Outdoor pools need a cover to reduce both cleaning and heating costs. These are priced from pounds 150 for the simplest to around pounds 3,000 for an automatic cover. Ideally use of a cover will save you around 20 per cent on your heating bill but if the cover is not easy to roll up and down, it is unlikely to be used enough to be effective. All pools demand continual maintenance, along with the heating, cleansing, filtration and ventilating equipment.

SPATA, the swimming pool and allied trades association, has put together a useful guide on all the different types of pools available and a list of all their members nationwide. The Swimming Pool Guide is available for pounds 5 from any member, or direct from SPATA.

Curchods, 01372 471010; Dixon Porter, 0181 878 2828; Chestertons, 01491 412888; Hamptons, 01628 74433; Stacks, 0171 622 0542; SPATA, 01264 356210.