Building a pool house means putting up an outbuilding next to your pool where you house the pool equipment and where you change, store things and lounge.
Broadly, you go through four steps. First check whether you need a permit, then lay a foundation, next build the structure (timber, prefab or masonry), and finally the equipment, electrics and finishing.
Budget for 5,000 to 25,000 euros, depending on size, material and whether you build it yourself or have it built. A simple timber pool house of 15 m² is a good deal cheaper than an insulated version of 40 m² with a kitchen, shower and toilet.
Important: a pool house is often bigger than what you can build permit-free. Check that first, before you put a spade in the ground.
What exactly is a pool house?
A pool house is an outbuilding next to your pool. It usually combines several functions in one space.
The most common functions:
- Plant room: this is where the pump, the filter and possibly the heat pump for your pool go. Out of sight, quiet and dry.
- Changing area: a place to change while you stay dry, with hooks and a bench.
- Lounge or covered area: a covered seating spot where you sit out of the sun or rain.
- Outdoor kitchen or bar: handy for food and drinks by the pool.
- Shower and toilet: so guests don’t keep tracking wet through the house.
- Storage: for cushions, inflatables, towels and maintenance kit.
You don’t have to combine everything. Many people start with equipment plus storage and a covered area, and expand later.
Do I need a permit for a pool house?
This is the most important question, and exactly where a pool house often goes wrong. A pool house is bigger than an ordinary garden shed, which means you go over the permit-free limit more quickly.
The exact rules differ by country and by local authority. The Dutch framework is a useful example. Since 1 January 2024 these rules fall under the Environment Act (Omgevingswet) and the Buildings Living Environment Decree (Bbl). For the structural side there is almost always a permit obligation (quality assurance), but the spatial side determines whether you may build without an environmental permit.
In principle a pool house may stand permit-free in the rear garden zone. That is the ground more than 1 metre behind the front of your home. Source: Informatiepunt Leefomgeving (IPLO).
How much floor area is allowed permit-free?
How much you may build permit-free depends on the size of your development zone (roughly the rear garden plus the ground under extensions). A sliding scale applies:
| Development zone | Maximum permit-free outbuilding |
|---|---|
| Up to 100 m² | 50% of the development zone |
| 100 to 300 m² | 50 m² + 20% of the part above 100 m² |
| Above 300 m² | 90 m² + 10% of the part above 300 m², up to a maximum of 150 m² total |
Source: IPLO, ancillary buildings.
A worked example. Say you have a development zone of 220 m². Then you may build 50 m² plus 20% of 120 m², which is 50 + 24 = 74 m². Note: this is the total floor area of all outbuildings together, so including an existing garden house or shed.
How tall can a permit-free pool house be?
The height is bound by rules too. Source: IPLO.
- Within 4 metres of the main building: no higher than 5 metres (or a maximum of 0.3 metres above the floor of the first storey of your house).
- Further than 4 metres from the main building: a flat roof may go up to 3 metres high. With a pitched roof the eaves may be a maximum of 3 metres and the ridge a maximum of 5 metres, with a formula that links the ridge height to the distance from the plot boundary.
- The building must stand more than 1 metre from publicly accessible ground.
When do you need a permit after all?
You definitely need an environmental permit if:
- Your pool house is bigger than the sliding scale allows.
- It gets too tall or stands too close to the public road.
- You build in the front garden.
- Stricter rules apply from the environment plan (formerly the zoning plan), a protected townscape or a listed building.
Always check your situation through the Omgevingsloket and, when in doubt, request a permit check from your local authority. The authority can set extra requirements. The rules above are the national baseline, not the full story for your plot. If you live outside the Netherlands, check the rules that apply with your local building authority.
Where is the best place to put a pool house?
The location determines how pleasant your pool house is to use.
Put it close enough to the pool so the equipment pipe runs stay short. Shorter pipes mean less pressure loss and a more efficient pump.
Look at the sun. A lounge or terrace on the south or west side catches the afternoon and evening sun. The plant room, on the other hand, you’d rather put on the shaded side.
Bear in mind the distance to the plot boundary. Permit-free, you may build right up to the boundary in the rear garden zone, but talking it over with your neighbours prevents hassle. With a roof that drains towards the neighbours, a distance of at least 0.5 metres is practical.
Think about the route too. You don’t want to cross a big stretch of garden with wet feet.
What foundation does a pool house need?
The foundation depends on the size and weight of your pool house and on what goes inside.
Concrete slab (shallow foundation): the most commonly chosen option for a full pool house. A reinforced concrete slab of roughly 15 to 20 cm thick on a well-compacted base gives a stable, level surface. Particularly recommended if you install equipment, water and a shower, because you’ll then want to set drains into the slab.
Concrete pads or paving slabs: for a lighter, timber pool house without heavy contents, you can work with concrete pads or a slab foundation. Cheaper and quicker, but less suitable for a heated space used year-round.
Important: lay the pipes for water and electrics as well as the conduits before you pour the slab. Chasing them in afterwards is expensive and messy.
Make sure the slab sits below the frost line or is well insulated, especially if a water pipe runs into it.
Timber frame, masonry or prefab?
There are roughly three ways to build the structure.
Timber frame (DIY build): you build a timber frame and clad it. Flexible, relatively light and doable yourself with some experience. Use durable or naturally rot-resistant timber such as Douglas fir, larch or pressure-treated softwood, because it’s often damp near a pool.
Prefab or self-build kit: you order a complete kit with pre-cut parts and assemble it yourself. Suppliers deliver kits with clear assembly instructions. Faster and with less chance of error, but less freedom in the design.
Masonry: brickwork or sand-lime block. Durable, low-maintenance and solid, but more expensive and labour-intensive. Usually you have this built (at least in part).
Which roof do you choose?
- Flat roof: clean, modern and suits a permit-free height. Combine it with a green roof if you like, for insulation and water storage.
- Mono-pitch roof: a single slope, good for sending rainwater in one direction and for adding extra height on the lounge side.
- Gable roof: more classic, and gives an airier sense of space.
Do you want to use the pool house all year or heat it? Then insulate the floor, walls and roof, and choose insulating glass. For pure summer use and storage, you can save on insulation.
Housing the pool equipment: what to watch for
The plant room is the functional heart of many pool houses. This is often where things go wrong, so take it seriously.
Space and layout: set aside enough room for the pump, filter and possibly the heat pump, and space around them to do maintenance. You need to be able to open and backwash a filter.
Ventilation: a plant room produces heat, moisture and sometimes chlorine fumes. Make sure it’s well ventilated, for example vents low and high, so air flows through. This prevents condensation, rust and mould.
Sound damping: pumps and heat pumps make noise. Don’t point the heat pump’s air outlet towards the neighbours, and consider sound-damping material on the walls.
Electrics: always have the electrics around a pool installed by a qualified electrician. Outdoors and in damp spaces you need a 30 mA residual-current device and a separate, waterproof circuit. Outdoor sockets and fittings must be at least IP44, and splash zones near water call for higher IP ratings.
Water and drainage: run a water pipe for the shower, tap or topping up the pool, and provide proper drainage towards the sewer or a soakaway. Remember the filter’s backwash water, which has to go somewhere.
Leave connecting the electrics and water to a professional. Combining water, power and people in swimwear makes mistakes here dangerous.
Step-by-step plan: how to build a pool house
Broadly, the build process looks like this.
- Design and dimensions. Decide on functions, dimensions and layout. Draw it up or use a ready-made building plan.
- Permit check. Check with your local authority whether you may build permit-free.
- Groundwork and foundation. Level the spot, lay pipes and conduits, and pour the slab or set the pads.
- Build the structure. Put up the frame, the walls and the roof. Finish it watertight.
- Install the equipment. Fit the pump, filter and heat pump, and have the electrics and water connected.
- Ventilation and insulation. Fit vents and insulate where needed.
- Finishing. Floor, walls, lighting, sanitary ware, kitchen and furniture.
Take your time over steps 1 and 2. A mistake in the dimensions or the permit costs the most money after the fact.
What does it cost to build a pool house?
Costs vary widely. They depend on size, material, finish and whether you build it yourself. The amounts below are indicative and include rough material costs, but not the pool itself.
| Type of pool house | Build yourself (material) | Have it built (total) |
|---|---|---|
| Simple timber pool house, equipment + storage (10-15 m²) | 3,000 – 7,000 euros | 8,000 – 14,000 euros |
| Timber pool house with lounge and covered area (20-30 m²) | 6,000 – 12,000 euros | 14,000 – 25,000 euros |
| Insulated pool house with kitchen, shower, toilet (30-40 m²) | 10,000 – 20,000 euros | 20,000 euros and up |
The big cost items are the foundation, the insulation, the sanitary ware and having the electrics and water installed by a professional. On the structure you can save by building yourself or choosing a self-build kit. Saving on equipment and installation is usually unwise.
Common mistakes when building a pool house
- Skipping the permit. A pool house is bigger than a garden shed and goes over the permit-free limit more quickly. Legalising or tearing it down afterwards is expensive.
- A plant room that’s too small or unventilated. Without ventilation you get condensation, rust and mould, and without space you can’t do maintenance.
- Forgetting pipes and drainage before the pour. Chasing into concrete afterwards is an expensive lesson.
- The wrong timber for a damp setting. Untreated or non-durable timber rots quickly next to a pool.
- Wiring the electrics yourself. Around water this is life-threatening. Have it done by a qualified electrician.
- No insulation while you want year-round use. Insulating afterwards is difficult and costly.
Frequently asked questions about building a pool house
How big can a pool house be?
Permit-free, the maximum size depends on your development zone, via a sliding scale: up to 100 m² you may build on 50%, and that percentage drops on bigger plots, up to a maximum of 150 m² total. If you want bigger, you need an environmental permit. These figures apply in the Netherlands. Source: IPLO.
Can I build a pool house myself?
Yes, with some building experience a timber pool house or a prefab self-build kit is doable yourself. Do have the electrics and the water connection done by a qualified installer, especially around a pool.
Which timber is best for a pool house?
Choose naturally durable or treated timber that can handle moisture, such as Douglas fir, larch, oak or pressure-treated softwood. Near a pool the setting is often damp, so untreated timber doesn’t last long.
Does a pool house need to be insulated?
Only if you want to heat it or use it all year. For a lounge, equipment and storage in summer, insulation isn’t necessary. For a year-round wellness or living space, insulate the floor, walls, roof and glass.
Where should the pool pump go?
In the plant room of the pool house, dry, well ventilated and as close to the pool as possible so the pipe runs stay short. Bear noise in mind and don’t point the heat pump’s outlet towards the neighbours.
Do I need a separate circuit for the electrics?
Yes. For a pool and pool house you use a separate, waterproof circuit with a 30 mA residual-current device. Outdoor sockets and fittings must be at least IP44. Have this installed by a qualified electrician.
Get started with a well-thought-out plan
Want to get going straight away with a complete, well-thought-out plan? At Fred’s DIY Plans you’ll find worked-out building plans for garden houses, covered areas and other building projects, with the right dimensions and materials lists, so you can get started with confidence.