Fiberglass vs Concrete Inground Pool: 7 Real Cost Differences

The most straightforward factor. For equivalent dimensions, a fiberglass inground pool typically costs between 15% and 25% less than a comparable concrete pool at the point of purchase.

On a concrete pool budget of €25,000, that represents a difference of between €3,750 and €6,250 in the initial investment alone. That gap does not disappear even when comparing premium fiberglass finishes against standard concrete construction.

A concrete inground pool requires a full construction process that rarely takes less than three months: excavation, formwork, concrete pouring, curing, tiling or rendering, waterproofing, and commissioning. Throughout that period, the garden is out of use and labour costs accumulate day by day.

A one-piece fiberglass pool is installed in 5 to 7 days once the excavation is prepared, ground conditions and planning permissions allowing. Fewer weeks of disruption, fewer installation days, and a much shorter wait before you can actually use the pool.

In a concrete pool, the water is in permanent contact with a porous surface, whether tile grout, render, or plaster. That porosity demands tighter chemical balance to prevent algae growth and surface deterioration, which means higher consumption of chlorine, pH adjusters, algaecides, and other products every season.

Fiberglass and polyester are non-porous materials with a smooth surface that makes it harder for algae to take hold. Maintaining water balance requires less chemical intervention. The difference in product consumption per season may seem small in isolation; over ten years, it is meaningfully cumulative.

Concrete is rigid. Ground movement, which is common in clay soils or in areas with seasonal moisture variation, can cause a concrete pool to develop cracks that compromise the seal and require costly repairs, sometimes running to several thousand euros depending on severity and accessibility.

Fiberglass and polyester have an inherent degree of flexibility that allows them to absorb minor ground deformation without structural damage. This is not a marginal difference: a single crack repair on a concrete pool can cost more than several years of combined chemical and cleaning savings on a fiberglass alternative.

The rough texture of tiled or rendered concrete surfaces retains more dirt, algae, and calcium deposits, which means more manual cleaning time or a more powerful automatic cleaner to keep the pool in good condition.

The smooth surface of a fiberglass pool reduces dirt adhesion and simplifies both manual and automated cleaning. Week by week the difference is modest; across the lifetime of the pool, the saving in time and resources is real.

A concrete pool, particularly as the surface finish ages, can experience some water absorption through the porosity of the walls, on top of the usual losses from evaporation. A one-piece fiberglass pool is fully watertight: there is no absorption through the material at any point of the shell.

In areas facing water restrictions or rising water costs, this difference has a genuine economic impact that, while difficult to quantify precisely for each installation, consistently points in the same direction as every other factor on this list.

Every pool eventually needs its finish renewed. In a concrete pool, that typically means removing the existing tiles, applying new render or coping, or resurfacing entirely: a process that can take weeks, generate significant waste, and represent a substantial renovation cost.

In a fiberglass pool, resurfacing means repainting the gel coat, a process that can be completed in 2 to 3 days at a fraction of the cost and without any major construction work.

Yes, and it is worth saying clearly. A concrete inground pool allows for fully custom shapes, non-standard dimensions, and specific adaptations to unusual plots or architectural constraints that fiberglass cannot always match. If your project requires a geometry that does not exist in any manufacturer's catalogue, concrete may be the only viable option, and the additional cost can be justified in that context.

If your project fits within the dimensions and shapes available in fiberglass pools, however, the seven factors above point consistently in the same economic direction.

Mon de Pra manufactures one-piece polyester fiberglass inground pools with over 30 years of experience across European markets. If you want to know whether one of our models suits what you are looking for and get an indicative cost for your installation, request a personalised quote.