A semi-inground pool sits halfway between an in-ground and an above-ground pool — with part of the structure buried and part visible above ground. Whether built from wood, concrete, composite, or steel, it's easier to install than a fully in-ground pool and works beautifully on sloped terrain. It's a smart, stylish way to add a durable and attractive swimming area to your backyard.
Here's everything you need to know to choose and install the right semi-inground pool for your space.
What Is a Semi-Inground Pool?
Compared to a fully in-ground pool — which requires extensive excavation — a semi-inground pool is faster and easier to install and uninstall. Part of the basin is dug into the ground, and part remains visible above it.
Better quality than a standard above-ground pool, a semi-inground pool — especially one clad in wood — brings a warm atmosphere and a genuinely classy look to any backyard. Great for relaxing, entertaining, and making the most of your outdoor space.
Here are some semi-inground pool design ideas to inspire you:
The Benefits of a Semi-Inground Pool
A semi-inground pool is a versatile and practical choice with plenty going for it:
- Adapts to flat, sloped, and terraced land — one of its biggest advantages over other pool types.
- Available in a wide range of shapes and sizes to match your space and budget.
- Less excavation work than a fully in-ground pool — faster and less disruptive to install.
- The raised coping makes it inherently safer than a fully in-ground pool — though standard pool safety measures are still required by law.
- More affordable than a traditional in-ground pool, with entry-level models available at accessible price points.
- A beautiful aesthetic addition to any backyard — especially when clad in stone or surrounded by plants. Pairs perfectly with pool landscaping ideas like a deck or terrace.
That said, a semi-inground pool does have a few limitations. Like an in-ground pool, it involves real construction work — excavation and backfilling — and once installed, it cannot be moved or disassembled. These are important factors to weigh up before committing.
How to Choose Your Semi-Inground Pool
Dimensions, shape, material, and budget are the four key parameters to guide your decision.
Dimensions
A semi-inground pool works well in small urban backyards as well as larger spaces. Pools under 108 sq ft require no administrative procedures — a real bonus. The standard semi-inground pool typically ranges from 20–26 ft in length and 10–16 ft in width.
If you have the space and want to swim laps, consider a lap pool configuration with a length of 40 ft or more.
Shapes and Materials
Rectangular is the most common shape, but semi-inground pools also come in round, square, oval, and kidney designs. Material choice largely depends on your budget:
Wooden Semi-Inground Pool
Warm, natural, and elegant, wood is the most popular material for semi-inground pools. A wooden semi-inground pool blends beautifully into any garden setting and pairs perfectly with a matching coping or deck. The main downside: wood is susceptible to moisture and requires regular maintenance.
Concrete Semi-Inground Pool
The most durable option, a concrete semi-inground pool is the closest equivalent to a fully in-ground pool. Once installed, it's permanent. Fully customizable and extremely reliable, it requires major construction work and professional installation.
Composite Semi-Inground Pool
Solid, easy to maintain, and non-slip, composite panels mimic a wide range of surface finishes. Moisture-resistant and safe underfoot — a great mid-range option.
Shell Semi-Inground Pool
A less common but convenient option, the shell pool comes in polyester or resin and is delivered ready-made to your home. Available in multiple shapes for easy customization.
Price
Budget depends on pool size, material, and installation work involved — including excavation, leveling, concrete slab, and backfilling. Always request quotes from multiple professionals to get an accurate picture. Kit models are the most affordable entry point, with prices increasing significantly for concrete builds. Don't forget to factor in accessories like a pool robot.
How to Install a Semi-Inground Pool
Regulations
Always check local zoning and planning rules before starting. As a general guide:
- Pools under 108 sq ft: no administrative procedures required in most cases (exceptions apply for protected or listed sites).
- Pools between 108 and 1,076 sq ft: a prior planning declaration is typically required.
- Pools over 1,076 sq ft: a full building permit is needed.
Always consult your local planning authority before proceeding.
Ground Preparation
Clear the site of vegetation, weeds, and any bulky elements. Mark the excavation limits and stabilize the soil to prevent settling. Dig trenches for pipes, and pour a concrete slab as the foundation base.
Basin Assembly
For modular panel pools, place and assemble the panels at the bottom of the excavation, bolt and brace the structure, and add concrete reinforcing bars. Then install the skimmer, liner, and filtration system. Semi-inground assembly is generally faster than in-ground pool installation.
Finishing Touches
Once the pool is assembled, add a cladding to integrate it seamlessly into your backyard — options include bamboo, wood, and PVC panels. Add a deck or terrace alongside the pool for the full outdoor living experience — and don't forget some fun inflatable pool floats to bring it all to life:
We hope this guide gives you everything you need to choose and install the perfect semi-inground pool for your backyard!
Wood or concrete: the decision summary
Both materials dominate the semi-inground market with opposite logics: wood favors looks and build speed, concrete favors durability and freedom of shape.
| Criterion | Wood | Concrete |
|---|---|---|
| Installed budget (indicative) | 10,000 to 25,000 € | 20,000 to 45,000 € |
| Lifespan | 15 to 30 years (class IV, treatment every 2 years) | 40 years and more |
| Build time | 1 to 2 weeks excluding earthworks | 4 to 8 weeks |
| Shapes | Round, octagonal, rectangular kits | Free, made to measure |
| Structure upkeep | Regular wood treatment | Nearly none |
For the details of each option: our guides to the wood semi-inground pool and the concrete semi-inground pool. For finishes, see cladding a semi-inground pool.
The full installed cost
The price of the shell alone is misleading. A complete semi-inground project adds up: the kit or structure, the earthworks (1,500 to 5,000 € depending on access and soil), the slab, the draining backfill, the plant room and filtration, the cladding and copings, and the mandatory safety device (in France, the 2003 safety law applies to semi-inground pools). Realistically, most complete projects land between 15,000 and 50,000 € installed.
Permits: what the rule says
In France, a semi-inground pool follows the general regime: above 10 m² of water surface, a prior works declaration; above 100 m², a building permit, plus the development tax. Rules vary locally: check with your town hall, or with your local building authority outside France, before signing.
A realistic project timeline
| Period | Step |
|---|---|
| September-October | Material choice, quotes, soil study if needed |
| November-December | Permit application (about 1 month of processing) |
| January-March | Earthworks and structural work, outside frost periods |
| April-May | Assembly, cladding, filling and start-up |
| June | First swims |
In short: a project decided in September swims the following summer. Now is when it all happens.
FAQ: Semi-Inground Pool
What is a semi-inground pool?
A semi-inground pool is partially installed in the ground (50 to 70% of its height) and partially above ground. It offers a compromise between a fully inground pool (more aesthetic, less visible) and an above-ground pool (cheaper, faster to install). It suits sloped terrain or mid-range budgets particularly well.
What are the advantages of a semi-inground pool?
The advantages of a semi-inground pool include: lower cost than a fully inground pool (€15,000–30,000 vs €20,000–50,000), better integration into the garden than an above-ground pool, the possibility of being relocated (depending on the model), a wide variety of shapes and finishes, and installation on sloped terrain without full excavation.
Do I need planning permission for a semi-inground pool?
Yes, if the pool volume exceeds 10 m³ or if it is covered. A prior work declaration is required between 10 and 100 m², and a full building permit above 100 m². A semi-inground pool falls under planning regulations just like a fully inground pool. Check with your local council based on your local planning rules.
How long does a semi-inground pool last?
Lifespan depends on the material: a semi-inground polyester shell pool lasts 20 to 30 years. A sprayed concrete basin can last 30 to 50 years. Treated wood or steel models with a liner last 10 to 20 years with proper maintenance. The liner itself lasts 10 to 15 years and can be replaced for €1,000–3,000.
How do I maintain a semi-inground wooden pool?
For a semi-inground wooden pool: treat the above-ground part with an outdoor wood oil or hardener every year. Check the liner and seals each spring. Carry out careful winterisation (cover, anti-frost floats, partial draining). The buried part is less exposed to the elements and requires less maintenance.
