Start planning now to enjoy a relaxing dip this summer

With 1.9 million pools, France is Europe's No1 pool country, well ahead of Spain, and sales in 2017 rose 20% as families used low interest rates to install 102,000 pools and create a lasting plus for the home.

Kit pools cost around €7,000 and from about €18,000 for an in-ground (enterré) pool, which is half the €35-€45,000 paid 10 years ago. Pools are also smaller today, about 45m2 from 130m2 in 2007 but, as ever, there is a world of difference between the good, the bad and the ugly.

Choosing whether the pool is in-ground or freestanding (hors sol) is a key decision but the main decision is the site – which should be sunny, protected from wind (but not too near trees for leaves to fall in the water) and with space nearby for lounging and maintenance.

Another priority decision is safety as pools must by law be protected by one of four means: either an alarm, barrier, cover or a shelter.

Alarms are the cheapest option but inevitably mean that someone has already fallen in and the others offer more security, with an abri shelter being the most expensive.

Rolling covers can be all-but-invisible when stowed away and have the advantage of retaining heat.

Property buyers should be wary of ‘for sale’ adverts saying there is ‘possibility of pool’ as this is no guarantee one can be installed. There may be local planning restrictions ruling out or restricting a pool project and buyers who see a pool as essential should get the notaire to write in a clause suspensive to the acte de vente specifying that permission for a pool of the desired dimensions be obtained.

Check local regulations with your mairie but Céline Gresil, of leading in-ground pool company Diffazur, said, in general, in-ground pools do not need any permissions if less than 10m2, although that is a quite small for family fun.

Pools sized from 10m2 to 100m2, can be built with a simple déclaration préalable de travaux on the official form Cerfa 13703 by registered letter to the mairie while bigger ones will need – surprisingly for a pool which is dug into the ground – a permis de construire.

Cheaper freestanding pools can be bought and set up very quickly and, unless in a protected area, need no permissions if they are used for less than three months of the year, are smaller than 10m2, not above 60cm in height and at least three metres from your boundary.

Building a pool will increase your taxe foncière and taxe d'habitation (although the latter is being phased out for most homes) and also be subject to the taxe d'aménagement, although increased payments may not apply for two years after contruction.

The taxe d'aménagement is a one-off payment. They may also apply to freestanding pools if they are surrounded by paving stones or built lounging areas.

It is difficult to determine costs for the first two taxes as different factors are covered by the calculations but the taxe d'amén­agement is a calculation of the pool size, the valeur forfaitaire and the taux tax levels set by commune and department.

The national valeur forfaitaire is €200, the commune taux is from 1-5% and department taux is 1%-2.5% so the maximum for a 10m2 pool is 10 x 200 x (5% + 2.5%) = 2000 x 7.5% = €150.

You have 90 days after the completion of works to declare your pool to the tax office by filling in the form Cerfa n° 10517*02 for Changement de consistance ou d'affectation des propriétés bâties et non bâties.

A simple pool in béton armé reinforced concrete from Diffazur will cost €20,000 including taxes and rival Desjoyaux is about the same but website guide-piscine.fr gives a summary of the various types available, including polystyrene or modular panel kits.

If you ask a company for a price devis this will give an exact figure.

Keeping the pool clean is a job most owners dislike and filtration can be built-in or added later with a surface skimmer, although full-pool filtering is better, while owners also need to take care of disinfection and maintaining low acid balance.