How to design a pool, step by step

How do you design a pool? Twelve steps, in order

To design a pool, make twelve decisions in this order: survey the garden, decide what the pool is for, choose the shape, set the length, width and depth, then the entry, the edge, the deck and materials, the plant room, and the garden, fence and lights. Then check the cost, look at it at night and from the house, and take one drawing to every builder. Two or three evenings at a screen and a weekend in the garden cover most of it.

The order matters because the early decisions end up in concrete: the shell, its depth, the steps and the edge are built once, while the deck, the lights and the planting can move later. Settle the permanent things while changing them still costs nothing.

Steps 3 to 9 happen on the Shape, Pool, Deck and Garden tabs of PoolPlanner's free 3D designer, on a model of your own pool at its real size, in the browser, with no account; the feature tour shows every control.

Step 1: survey the garden before you draw a pool

What size pool fits your garden is a subtraction, and it starts with a tape measure. Measure from the house to each boundary, and find the real boundary lines rather than the fences, because setbacks run from the line. A setback of 3′ 3″–9′ 10″ (1–3 m) is common, but your local authority sets yours, so ask before you draw anything near an edge.

Then walk the garden with a list. Access: a full-size excavator needs a route about 8′ 2″–9′ 10″ (2.5–3 m) wide, a mini excavator about 4′ 11″ (1.5 m). Sun: where the house's shadow lies at noon, three and six. Wind: which wall the leaves will collect on. Slope: a fall of 1′ 8″ (0.5 m) across a 32′ 10″ (10 m) pool means a retaining wall or fill. Services: buried cables, pipes, drains and any septic tank. Trees: keep the hole outside their drip line.

Allow roughly twice the water area for the pool with its deck, walk-around and plant room. In the designer, open the Garden tab on any pool: the plot is the garden beyond the deck, typed side by side, or a custom shape whose corners you drag to fit an awkward plot. It is drawn level, and the designer does not know where north is, so the slope and the shadows stay on your sketch.

Steps 2 and 3: what the pool is for decides its size and shape

Decide what the water is for before what it looks like, because the use sets the size class; the size guidance in this library takes each in turn. Cooling off is a plunge pool of up to about 140 sq ft (13 m²); children and short lengths, a compact pool of 161–258 sq ft (15–24 m²); a family pool that does a bit of everything, 258–538 sq ft (24–50 m²), which is why 26 × 13 ft (8 × 4 m) is Europe's most-built size. Allow about 43 sq ft (4 m²) per person in the water at once.

The shape guide covers all ten shapes. Straight ones — rectangle, rounded rectangle, Roman, Grecian — swim best and cost least to form; curves — oval, round, kidney, figure 8 — sit more softly in a garden but give up length. An automatic slatted cover runs on straight rails, so if you want one, the pool is a rectangle or close to it.

In the designer's Shape tab, pick a shape, type your length and width, read the water surface, then try the next shape at the same size. Or start from the plan library: every plan opens in the designer at its real size and depths.

Every decision on this list costs nothing to change on a screen, a little on paper, and a great deal once it is concrete.

Step 4: how long, how wide and how deep

Width decides whether the pool swims: 8′ 2″ (2.5 m) is the narrowest that takes a stroke without finding the wall, and 11′ 6″–13′ 1″ (3.5–4 m) lets two people pass. Length sets the rhythm: from 26′ 3″ (8 m) it is swimming, and at 32′ 10″–39′ 4″ (10–12 m) the turns stop dominating. If the garden forces a cut, take it off the length and keep the width.

For depth, first ask whether you need two. A uniform depth of 4′ 5″–4′ 7″ (1.35–1.4 m) suits lap pools, plunge pools and many families. The classic family profile runs from 3′ 11″ (1.2 m) to 5′ 11″ (1.8 m), flat for the first third, then no steeper than about 1:3. Head-first diving needs 7′ 10″ (2.4 m) or more: a different pool, not a deeper corner. And every extra 7 7/8″ (20 cm) on an 26 × 13 ft (8 × 4 m) pool is 1,691 gal (6.4 m³) more water to heat, every year.

The Shape tab takes length, width and both depths as sliders or typed numbers. The depths are measured from the deck, as a builder sets out the shell, while the toolbar's volume is the water the pool actually holds after the freeboard and the steps. Shell view hides the deck to show the slope from the side.

Steps 5 and 6: steps, ledge or bench, then the edge

Built-in steps, a tanning ledge and a bench are cast with the shell, so they come before anything bolted on. Comfortable steps have 11 3/4–13 3/4″ (30–35 cm) treads, 7 1/8–9 7/8″ (18–25 cm) rises and at least 3′ 11″ (1.2 m) of width, and four of them take about 4′ 7″ (1.4 m) of swim length. A ledge works at 5 7/8″ (15 cm) of water with 6′ 7″ (2 m) of reach for a lounger; a bench sits 15 3/4–17 3/4″ (40–45 cm) under the surface. Put the entry at the shallow end, nearest the terrace.

Then the edge system. A skimmer pool holds its water about 5 7/8″ (15 cm) below the coping, with one skimmer per roughly 269 sq ft (25 m²): the simplest and cheapest edge. A deck-level overflow brings the water flush with the deck and typically adds 15–30 % to the shell, plus a balance tank. A raised edge lifts the rim 15 3/4–23 5/8″ (40–60 cm) into a seat and can suit a slope. Each changes the wall tops and the pipework, so decide a must-have edge together with the shape.

Both are on the designer's Pool tab: straight or Roman steps under Getting in and out, a bench or a ledge under Sitting in the water, each with its own sizes and dragged along the wall into place. The Edge type row switches between skimmer, overflow and raised, and the coping and the water line follow.

Steps 7 and 8: the deck, the materials and the plant room

The interior finish sets the colour of the water: white gives a bright turquoise, anthracite a dark mirror. Tile lasts longest, plaster and membrane are renewed every 10–15 years, and a tiled band of 7 7/8–9 7/8″ (20–25 cm) at the water line pays on any of them. The coping is a ring of stone, concrete or timber 11 3/4–15 3/4″ (30–40 cm) wide, and the deck goes where life happens: 8′ 2″ (2.5 m) or more where the loungers stand, about 3′ 3″ (1 m) where people walk past.

The plant room is the step most drawings skip, and it is half of the circulation. Pump, filter and heater need a pad of about 3 × 8 ft (1 × 2.5 m), more with a heat pump, which wants open air around it and hums at night. Keep it within about 32′ 10″ (10 m) of the pool and away from bedrooms, and plan one return inlet per 161 sq ft (15 m²) or so, all angled the same way round.

The Deck tab sets the deck's material and its width on each side. On the Pool tab, Interior and Coping open as pictures, painted in any colour or photographed (half of the photographs are Pro), and the Plumbing group places the inlets and drains. There is no plant room to draw, so widen the deck or the plot on that side and mark the spot.

Step 9: the garden, the pool fence and the lighting

The pool barrier is a legal question first. Rules differ by country and town, but a common pattern is a fence at least 3′ 11″ (1.2 m) high all round, with no gap a small child fits through, no footholds outside and a self-closing, self-latching gate; some places accept a safety cover or door alarms as part of it. Ask before you draw, since the fence takes a strip of garden, and plant nothing that drops leaves over the water.

Plan the lighting the same evening. One underwater light per 161–215 sq ft (15–20 m²) is plenty, so two or three for an 26 × 13 ft (8 × 4 m) pool, set about 19 5/8″ (50 cm) below the surface on the wall nearest the terrace and shining away from it. Keep them clear of the steps and the ledge, choose one warm white, and lay an empty conduit to every future light while the ground is open.

In the Garden tab, chairs, a table and a parasol are free and sun loungers are Pro; the shuffle, two planting styles and a hedge are free, while six more styles, the plant catalog, a timber or walled boundary and a glass or picket pool fence are Pro. The lights sit on the Pool tab: up to eight, in five colours and four layouts.

Steps 10 and 11: check the cost, then look at it at night

Check the build cost while changes are still free. A useful estimate is a range, names its market and lists what it leaves out, so read the exclusions first. Size and depth scale almost everything, a deck-level edge adds to the shell, and the deck and finishes are where budgets quietly double.

The designer's toolbar keeps a live total, free for everyone: a rough range from published 2025–26 rates, priced for your market, from US states and metros to twelve European countries, Australia, New Zealand and Canada. It prices a concrete pool built in place (in Europe a liner over concrete usually costs less) and leaves out heating, fencing, landscaping, an electrical upgrade and furniture; Pro breaks it down by building stage. It is an estimate to plan with, never a quote.

Then look at it the way you will live with it. Switch to Night: do the lights make the water glow, or glare at the terrace? The designer has no model of your house, so walk the camera to where the back door will be (W A S D, with E and Q for height, or drag and pinch on a phone), drop to eye level and hide the interface. That is where surprises turn up: steps hidden from the kitchen, a deck too narrow by the door.

Step 12: take it to builders, and what a 3D plan cannot do

Turn the finished design into one brief: size and depths, shape, entry, edge, finish, coping, deck, cover, heating, lighting and the plant room's place. A share link carries the whole design, and anyone who opens it can edit a copy of their own, no account needed. For a drawing a builder can mark up, the Pro blueprint draws your design to scale: a plan and a section with dimensions and depths, the fittings numbered, and with a garden the fence line and a planting plan.

Hand the same brief and drawing to three builders, so the quotes compare line by line; the questions to ask a pool builder cover the rest. Ask each to price your design as drawn, and any change they suggest separately.

And know what the drawing is not. It is not a survey: the garden is drawn level, with no soil, groundwater or buried pipes, so levels, boundaries and a trial pit come from the site. It is not engineering: walls, steel and drainage are for the builder or a structural engineer, as the blueprint's own disclaimer says. It is not a permit: what you may build, and where, is your local authority's decision. A 3D plan settles what you want; the ground and the rules settle what you can have.

What goes wrong in practice

1. Starting with the tiles and the lights

   Finishes are the easiest thing to change later. Shape, depth, entry and edge are cast into the shell, so settle them first.

2. Drawing the pool without its garden

   With its deck, plant room and fence, a pool takes roughly twice its water area. Draw them all, or the pool that fits on paper leaves nowhere to sit.

3. Taking the model for a survey

   A 3D plan draws a level garden with nothing under it. Slope, soil, groundwater and buried services come from the site, and they move the price more than any finish.

4. Only ever looking from above

   From overhead every pool looks right. Stand at the back door at eye level, and again at night, before the steps and the lights are fixed.

5. A different brief for every builder

   Three quotes for three different pools cannot be compared. Send everyone the same drawing, the same depths and the same equipment list.