How to Build a DIY Dipping Pool: Design, Walls, Plumbing and Heating

Last updated: September 2026

Fancy a dip? A dipping pool is one of the most satisfying things you can build in a garden or backyard. It’s small enough to be a realistic DIY project, it’s somewhere to cool off on a hot day, and if you heat it, it’s somewhere to soak for much of the year. Leave it cold and it’s the perfect partner for a hot tub or sauna.

In this guide I’ll go through the design decisions, the wall options, the plumbing, the heating and the safety side, so you know what you’re taking on before you pick up a spade.

What is a dipping pool?

A dipping pool is a small, fairly deep pool for getting in, cooling off and getting out. You’ll hear “dipping pool”, “plunge pool” and “dip pool” used for much the same thing. I’d think of a dipping pool as the small end of a plunge pool: somewhere you can stand with your shoulders under, but not a pool for swimming lengths.

	Dipping pool	Plunge pool	Cold plunge
Typical size	Around 2–4m (7–13ft) long	3–6m (10–20ft) long	Usually one person
Water depth	1.2–1.4m (4ft–4ft 6in)	1.2–1.5m (4–5ft)	1–1.2m (3–4ft)
Temperature	Unheated, or heated to pool temperature	Unheated to about 30°C (86°F)	Kept cold, often with a chiller

If you want the full build from dig to first dip, my DIY plunge pool guide is the step-by-step version of this post. If you’d like benches and loungers for sitting with a drink, see the cocktail pool and spool guide. And for a real example, have a look at Roger’s DIY dipping pool in the Dominican Republic.

Design considerations

• Size and shape. This depends on your space and how you’ll use it. Squares and rectangles are far easier to build and tile than curves. If you might want to swim on the spot one day, make it at least 4m (14ft) long so a counter current swim jet works properly. See swim jet considerations.
• Depth. Shallow enough to stand, deep enough to get your shoulders under. Around 1.2–1.4m (4ft–4ft 6in) of water suits most adults. The hole has to be roughly 350–400mm (14–16in) deeper than the water to allow for the sub-base, slab, waterproofing and tiles. Nobody should ever dive into a pool this shallow.
• Steps and a bench. Built-in steps with a handrail make getting in and out safer, especially for older users. A bench along one side gives you somewhere to sit.
• Heating and circulation. Decide now. Both affect the size of the control room and the power supply.
• Lighting. An underwater light looks fantastic and makes night-time use safer. It must be extra-low voltage (12V) in the water. See the ultimate guide to hot tub and pool lights.
• Surround and landscaping. Non-slip paving or decking, some planting, and perhaps a water feature for sound. See privacy ideas for screening.
• Accessibility. If anyone in the family has limited mobility, plan wide, shallow steps and good handrails now. It’s much harder to add them later.
• Safety. A barrier, a lockable cover and non-slip surfaces. More on this below.

Wall options: block, poured concrete or ICF?

There are three realistic options for the walls. Whichever you pick, it sits on a reinforced concrete slab with rebar tied up into the walls.

	Concrete block (CMU)	Poured concrete	ICF
Cost of materials	Lowest	Low to medium, plus formwork	Highest upfront
Strength	Strong once core-filled with concrete and rebar	Very strong if reinforced properly	A solid reinforced concrete wall inside the foam
Insulation	Poor, unless you add it	Poor, unless you add it	Built in, which matters if you heat it
DIY difficulty	Heavy, and blocklaying is a skill, but very doable	The formwork must take the weight of wet concrete, and a blowout is a disaster	Light, easy to cut, easy to run pipes through
Shapes	Best for squares and rectangles	Any shape you can build a form for	Mostly straight walls, with some curve options

My own tub is block, and it’s perfectly good. But if I built again I’d use ICF, which is why it’s my recommendation for most DIY builds. It isn’t “skilled labour” in the way blocklaying is. It’s more like Lego for adults, and you get the insulation for free. Poured concrete isn’t really lower maintenance than the others either: every option ends up rendered, waterproofed and tiled, so the finish is what you maintain. More detail in block, ICF or poured concrete?, TubBlox and ICF walls and building with cinder block.

Don’t skimp on the structure

A 3m x 2m (10ft x 7ft) dipping pool with 1.3m of water holds nearly 8,000 litres, which is about 8 tonnes. So:

• Lay a compacted sub-base and a reinforced ready-mix slab, not a sand and cement mix by the barrow.
• Fit a hydrostatic relief valve so groundwater can’t lift or crack the shell when it’s empty.
• Tie vertical rebar in the walls into starter bars from the slab.
• Render, then apply a pool-rated waterproofing membrane in two coats, and flood test before you tile. See waterproofing, grout and tile adhesive.

Plumbing considerations

1. Filling and topping up. You need a tap nearby, and ideally an automatic top-up. See auto top-up systems. A hose over the edge is fine. If you plumb in a permanent fill line, it needs backflow protection so pool water can never be drawn back into your drinking water, so ask your plumber what your local rules require.
2. Emptying and surface water. Plan how you’ll drain it (a submersible pump or a drain valve in the plumbing), and slope the paving so rainwater runs away from the pool, not into it.
3. Circulation and filtration. Water leaves through the skimmer and main drains, goes through the pump and filter, then back through the return inlets. Use two main drains at least 3ft (1m) apart with anti-entrapment covers. In the USA, the VGB Act requires ANSI/APSP/ICC-16 drain covers. See installing a main drain and installing a skimmer.
4. Sanitising. You don’t need a separate plumbing system for chemicals. Chlorine or bromine goes in by hand, from a floater, or through an inline feeder or salt cell on the return line after the heater. UV-C can sit on the return line too, but it doesn’t replace a residual sanitiser.
5. Heating or cooling. A heat pump plumbs in after the filter. Leave room for it in the control room. More below.
6. Water features. A waterfall or water blade needs its own pump and pipework, so plan it from the start.
7. The control room. Make it bigger than you think, keep it close to the pool, and give it a drain. See control room design considerations.

Use pressure-rated PVC with solvent-weld joints, and don’t mix imperial and metric pipe. See hot tub pipe explained and the perfect PVC solvent weld joint.

Heating options

For scale, raising 8,000 litres (about 2,100 US gallons) by 10°C (18°F) takes roughly 93kWh of heat. A 3kW spa heater would need over 30 hours to deliver that, even with no heat loss, so the small heaters used on hot tubs are too slow on their own.

Option	Pros	Cons
Air source heat pump	Cheapest to run. The US DOE puts pool heat pumps at a COP of 3 to 7. Many can cool as well as heat.	Higher upfront cost, slower heat-up, and less output below about 10°C (50°F). Some noise, so think about where it goes.
Gas or propane heater	Fast heat-up in any weather	Costs more to run than a heat pump, needs a gas supply or tank, and must be installed by a qualified gas engineer
Electric heater	Cheap to buy and simple	Every kW of heat costs a kW of electricity, so it’s the most expensive to run and slow on a pool
Solar	Free heat in summer	Needs space and sun, with little output in winter

Whatever you choose, a good insulated cover makes the biggest difference. The DOE says a cover can cut pool heating costs by 50–70%, because evaporation is by far the biggest heat loss. See how to choose the right air source heat pump and how noisy is an air source heat pump?

Or keep it cold

Unheated, an in-ground pool is properly cold for much of the year in the UK and the northern USA, which makes it a great cold dip next to a hot tub or sauna. Take cold water shock seriously: the US National Weather Service warns it can be dangerous even at 10–15°C (50–60°F). Get in slowly, never alone, and check with your doctor first if you have a heart condition. See how to build a DIY cold plunge pool.

Electrics

Leave this to a qualified electrician. In the UK, the IET says outdoor pools and hot tubs fall under BS 7671 Section 702, with an isolator outside zone 1, 2m from the edge, and the work is notifiable under Part P. In the USA, NEC Article 680 requires GFCI protection and equipotential bonding of the rebar and the paving out to 3ft from the pool, using solid copper no smaller than 8 AWG. The rebar bonding has to go in before you pour. See A guide to hot tub electrics and ground bonding.

Permits and safety barriers

• UK: In England, an outdoor pool often doesn’t need planning permission, but check with your council for listed buildings, conservation areas, national parks and green belt. There’s no law requiring a fence around a private pool, but RLSS UK recommends secure fencing at least 4ft high.
• USA: Expect a building permit, an electrical inspection and a barrier. The CPSC’s barrier guidelines call for at least 48in, no gap a 4in sphere can pass through, and self-closing, self-latching gates that open away from the pool. Local codes set the rules. See Do I need a permit?
• Everywhere: a lockable cover, non-slip surfaces, a handrail on the steps, and an adult supervising whenever children are around.

Common dipping pool mistakes

• Digging to the water depth and ending up with a pool that’s too shallow.
• No hydrostatic relief valve, a single main drain, or a slab without rebar.
• Relying on waterproofing additives instead of a pool membrane.
• Expecting a small spa heater to heat a pool.
• No cover, which means big heating bills and a pool full of leaves.
• No barrier.

Planning your own dipping pool?

My plunge pool / cocktail pool plans suit a dipping pool perfectly. You get architectural drawings, plumbing layouts, steps and a bench, a build guide and videos, in imperial and metric. The smaller sizes are the ones most people choose for a dipping pool: 10ft x 7ft, 12ft x 8ft and 14ft x 7ft. Larger sizes go up to 20ft x 10ft.

If your space is an odd shape, try the free Tub & Pool Designer Pro software, and I can turn your design into architectural CAD and a 3D plumbing design. Planning a dipping pool next to a hot tub? The hot tub and pool combo design consultancy covers both, and my hot tub pool combo guide explains the options.

FAQs

How deep should a dipping pool be?

Around 1.2–1.4m (4ft–4ft 6in) of water, which lets most adults stand with their shoulders under. Dig roughly 350–400mm (14–16in) deeper than that for the slab, sub-base, waterproofing and tiles.

What’s the difference between a dipping pool and a plunge pool?

Not much. A dipping pool is usually at the small end of the plunge pool range, used for a quick dip rather than for swimming on the spot.

What’s the best material for the walls?

For most DIY builds, ICF. It’s light, easy to work with and insulated. Core-filled block is cheaper and works well. Both need rebar tied into a reinforced slab.

Do I need to heat a dipping pool?

No. Unheated, it’s a great cold dip. If you want to use it warm outside summer, an air source heat pump and a good cover are the way to go.

Do I need a fence around a dipping pool?

In most of the USA, yes: typically 48in with a self-closing, self-latching gate. In the UK it isn’t a legal requirement for a private pool, but RLSS UK recommends at least 4ft.

Building a dipping pool? Drop your questions in the comments below. I read them all.

Cheers,
Andi

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Thanks - Andi

 

Hi, Andi here. I own Buildahottub.com and also write all of the articles and info pages on the site. Some years back now, I built my own hot tub but struggled to find the information I needed. So, once my tub was complete, I started this website to help others in their own pursuit of hot tub and plunge pools DIY building information.

Fast forward to 2025, I've helped over 1400+ DIY customers just like you all over the world build hot tubs and pools. Have a good look around the site, there are lots of resources here. Please do get in touch if I can help you. - Cheers, Andi