It's often the first question future owners ask – and yet it’s rarely the right one to begin with. The choice of technology should come after On-site diagnosis and definition of your needs, not before. Once these foundations are laid, the decision becomes considerably simpler: in most cases, two or three criteria are enough to naturally eliminate one or two options. Here is an honest comparison, without commercial jargon.
Concrete pools: sustainable customisation
It's the benchmark technology, the one that immediately springs to mind when talking about a «home» swimming pool. It still represents the majority of in-ground swimming pools built in France and Luxembourg. Its main strength: total design freedom.
Who is she for?
Concrete pools are the ideal solution if you have a precise architectural project – an unusual shape, overflow, multi-level pool, integration on a steep slope, or simply dimensions that go beyond standard catalogues. It is also the only technology that adapts without constraint to difficult terrain: rocky ground, narrow configurations, limited access for construction machinery.
It is also suitable for owners with a long-term view: a well-built and well-maintained concrete pool can last over 40 years without major structural intervention. The interior lining (tiles, liner, marble plaster) needs to be renewed every 10 to 20 years depending on the materials, but the structure itself is virtually permanent.
What you need to know before choosing
- Construction time: 6 to 12 weeks on average, sometimes longer for complex projects. The concrete structure needs time to dry and stabilise before being filled with water.
- Budget: This is generally the most expensive solution — expect to pay between €25,000 and €70,000 depending on the size, finish, and equipment. High-end tiling or architectural finishes can push the budget well beyond that.
- Interview Tiled or shotcrete surfaces are rougher than polyester, which slightly encourages algae growth. A high-performance robot cleaner largely compensates for this drawback.
- Future flexibility A concrete pool can be modified, extended or transformed years after its construction – which is impossible with a shell.
To go further into the construction specifics, consult our guide on the In-ground swimming pools.
The fibreglass shell swimming pool: quick installation
Manufactured in a factory in one piece, delivered by truck and installed in a few days: the polyester shell is the fastest solution on the market. From the delivery of the shell to the first swim, allow for 2 to 3 weeks of active work on site – provided the groundwork has already been completed.
Who is she for?
The shell is perfectly suited for tight budgets, stable ground without any particular geological constraints, and for owners who want a functional pool quickly without getting bogged down in complex technical choices. It is also the easiest solution to maintain: the smooth polyester surface naturally resists algae adhesion and does not trap limescale as easily as a textured surface.
What you need to know before choosing
- Fixed shapes and dimensions You choose from a catalogue. Manufacturers offer dozens of models, but if you have a specific idea for a bespoke shape, a stock shell isn't the answer.
- Access restriction: The shell arrives in one piece on a flatbed truck. If your garden is difficult to access (narrow gate, passage under electrical wires, steep terrain), check the logistical feasibility before making any commitment.
- Risk of ventilation failure As mentioned in Part 2, a high water table is a serious constraint for shells. The lightness of the structure, which is an advantage during installation, becomes a risk during dewatering if specific precautions are not taken.
- Lifespan A quality polyester hull lasts 20 to 30 years. The gelcoat (surface finish layer) may require renovation after 15 to 20 years depending on usage and maintenance.
- Budget: Between €15,000 and €35,000 all-inclusive (excluding earthworks and decking), this is generally the cheapest solution for a quality inground pool.
The kit pool (panels): the compromise between accessibility and budget
Between the rigidity of concrete and the constraints of shell construction, on-site assembled kit pools occupy a well-defined niche: that of good value for money for standard-sized projects, without particular architectural ambition but with a real desire for savings.
Who is she for?
Pool kits are aimed at homeowners who wish to slightly customise the dimensions (length, width, depth) without opting for a full concrete construction, and who want to control their budget by breaking down the costs. Some kits are designed for installation by a local pool builder, while others allow for partial self-assembly if you have DIY skills – which can significantly lower the final cost.
The panels are made of galvanised steel, aluminium or polypropylene depending on the range. The interior lining is generally a reinforced liner, which offers good value for money and is easily replaced every 10 to 15 years. For more information, please consult our Complete guide to kit swimming pools.
What you need to know before choosing
- Flexibility of dimensions Larger than the shell, less complete than concrete. Most manufacturers offer modules of 50 cm by 50 cm which allow the size to be adapted to your available space.
- Construction time: 2 to 4 weeks depending on complexity and provider, an intermediary between the shell and the concrete.
- Budget: Between £10,000 and £30,000 depending on the materials and equipment — this is often the most accessible solution for a correctly sized pool (8 × 4 m).
- Long-term durability A well-installed and well-maintained steel kit lasts 20 to 25 years without any issues. Check the quality of the galvanisation and the sealing of the junctions between panels – this is where the differences between brands lie.
- Above-ground or semi-underground options Some kits are designed for installations above ground or built into a slope, which opens up interesting architectural possibilities for sloping terrain.
Comparative summary: which technology for which profile?
| Criterion | Concrete | Polyester casing | Panel kit |
| Construction deadline | 6 – 12 weeks | 2 – 3 weeks | 2 – 4 weeks |
| Average budget (excluding earthworks) | 25,000 – 70,000 € | 15,000 – 35,000 € | £10,000 – £30,000 |
| Customisation | Total | Catalogue only | Partial (modules) |
| Easy care | Average | Excellent | Good |
| Structural lifespan | 40 years and over | 20 to 30 years | 20 – 25 years |
| Suitable for difficult terrain | Yes | Limited | Yes |
| Ideal for | Bespoke, long-term project | Speed, controlled budget | Tight budget, adaptable dimensions |
Filtration: the silent engine of water quality
We often choose our pool for its aesthetic appeal, but it's the filtration system that truly determines the quality of the water you'll be bathing in. A magnificent pool with an undersized or unsuitable filtration system will systematically be cloudy, green, or irritating to the eyes. Here are the three main types of filters, without unnecessary jargon.
The Sand Filter: The Accessible Standard
This is by far the most common solution. Water passes through a bed of siliceous sand which retains suspended particles. Simple, robust, economical to purchase (€200 to €600) and easy to maintain (weekly backwashing), the sand filter is the starting point for the vast majority of residential swimming pools. Its limitation: it retains particles larger than 20-30 microns, allowing very fine particles responsible for slightly hazy water to pass through.
Recycled glass filter: improved filtration
It works on the same principle as a sand filter, but the sand is replaced by crushed recycled glass. The difference is significant: glass filters down to 5 microns (compared to 20-30 for sand), resulting in much clearer water. It uses fewer chemicals because the water is cleaner exiting the filter, requires backwashing less often, and lasts longer than sand (no need for replacement for 10 years compared to 5 for sand). The extra cost to purchase is moderate – expect €100 to €200 more than an equivalent sand filter. It often represents the best value for money for a family swimming pool.
The cartridge filter: compactness above all
Without a backwash valve or water drainage, the cartridge filter is the most compact and simplest solution to install. It is particularly suitable for small pools (under 30 m³), above-ground pools, and situations where technical room space is very limited. Its main drawback: the cartridge must be removed, rinsed manually, and replaced every 1 to 3 years depending on water load. For larger pools or intensive use, the cost of replacing cartridges can become significant over time.
How to choose your filtration system
Whatever technology is chosen, two rules apply without exception:
- Never undersize the pump It must be able to circulate the entire volume of the pond in a maximum of 4 to 6 hours. A 60 m³ pond requires a pump capable of processing at least 10 to 15 m³/hour. An undersized pump partially compensates by running for longer – and therefore consuming more energy for a lesser result.
- Investing in a variable speed pump: These models automatically adjust their flow rate to suit requirements (normal filtration, cleaning, heating). They consume 50 to 70% less energy than a fixed-speed pump and generally pay for themselves within two to four seasons. It is one of the most cost-effective investments in the entire project.
A good filtration system is unseen – but you feel it with every swim. Crystal-clear, balanced water that's gentle on the skin is a sign of a well-sized filtration system, not an overdose of chemicals.
Now that you have a clear view of the available technologies, it is time to address what quotes don't always show at first glance: the real budget, hidden costs, and the long-term financial reality of a swimming pool.
