A splash in the back garden

Swimming-pools are the stuff of summer fantasies. They can help sell your house, too, says Amanda Seidl

England in a heatwave is tiresome. Public parks are littered with sweaty bodies, roads to the coast are jammed with cars, wasps plague would-be picnickers and drought-stricken gardens offer about as much comfort as a hair shirt in a sauna.

It need not be so unpleasant. Imagine waking to another blistering summer's day - the sun burning a hole in the curtains, the temperature nudging 80F before breakfast. Shimmering among the perennials is an oasis of clear blue water which you plunge into - the perfect start to the day.

Houses with swimming-pools are enjoying a halcyon summer - in a sluggish market, any feature that can add appeal to a property is a step towards a faster sale.

Of course, there are downsides to pool ownership. Quite apart from the cost of maintenance and heating, there are the friends you never knew you had, who invite themselves round for the day and arrive with a car full of children who stampede through your dahlias and run dripping through the house in search of the loo. But even this occasional invasion of privacy beats listening to the squeals of delight from the neighbour's swimming- pool, while your overheated offspring watch their rubber paddle-pool deflate again.

Swimming-pool manufacturers are expecting sales to soar next year, thanks to this summer's record temperatures, as pools move up the home improvement priority list. DIY pool kits start from as little as pounds 1,330, and an average outdoor pool costs about pounds 8,000.

However, if you are thinking of building a pool in your back garden, do not expect to recoup your investment in the property's value. While most pools are an added feature that might make the house more saleable, the cost of installation will not necessarily be reflected in the asking price.

James Laing, of Strutt & Parker, believes that at least half the pools built this summer will reduce the value of the property. "There is nothing more depressing than looking out of your bedroom window in December at a murky, blue-bottomed puddle," he explains.

Until this exceptional summer, most agents would have agreed that outdoor pools were more of a liability than an asset. Robin Bertram, of Bidwells' Northampton office, points out that they appeal to a limited section of potential buyers. "The elderly are concerned about running costs, and people with young children are worried about the risk of drowning," he says. "I would always advise people to invest in a conservatory first, a tennis court second and a swimming-pool last."

Bidwells is offering the combination of house, tennis court and pool at The Old Rectory, near Norwich. The late Georgian house sits in six acres of gardens with tennis courts and heated swimming-pool screened by trees and shrubs. A fine house like this, priced at pounds 490,000, is hardly dependent on a pool for its saleability, but it does add to the impression of a luxurious lifestyle.

The further south you go, the more common it is to find a swimming-pool in the garden. Sara Batting, who runs her own estate agency in Reading, thinks a well-built pool is a big attraction with a family house.

Typical of a well-matched pool and house is a property she is marketing in Spencers Wood, near Reading. Here, the four-bedroom Edwardian house has been improved by a large conservatory and a new pool, with converted outbuildings providing a Jacuzzi, sauna, showers and leisure room. Best of all, the neat, kidney-shaped pool does not dominate the pretty, wooded gardens.

Quality of construction and a design to complement the house and garden will determine whether the pool is an asset or a liability. An Olympic- sized pool in the garden of a two-bedroom bungalow may be a talking point, but it will not add to the property's value.

For a stylish setting, few houses can beat Ashley Hill House, near Salisbury, which Savills is marketing for about pounds 600,000. The pool is placed to make the most of the dramatic views over the Wiltshire countryside, and terracing and planting add an Italian ambience. "Outdoor pools are wonderful in the right setting," agrees Ian Stewart of Savills, "but on the whole, indoor pools are consistently more popular."

Indoor swimming-pools are in a completely different league, both in terms of initial costs - anything from pounds 25,000 - and in the difference they make to the property. A luxury property's value can be enhanced by two to three times the cost of installing a well-designed indoor pool.

While small is beautiful in an outdoor pool, the opposite applies to the indoor version. A small pool squeezed into a redundant outbuilding will add little to a property's appeal but an aesthetically pleasing, spacious leisure facility will be a definite attraction.

Top-of-the-range pools belong to houses such as The Manor at Caunton in Nottinghamshire, which Strutt & Parker is marketing for about pounds 3m. Along with 20 acres of parkland, stables and an arboretum, the listed seven-bedroom house has a barn-style leisure complex with a 40ft pool concealed beneath an oak dance floor.

Anne Spackman is on holiday