Where to put a swimming pool in your garden: sun, boundaries, pipes and planning

The pool builder will almost always ask: “So where do you want it?” The most common answer, “at the bottom of the garden”, is rarely the best one. A badly placed pool is in shade by 4 pm in September, fills up with leaves, can't be seen from the house, or lands right on top of the sewer pipe.

This guide goes through the criteria in the order they rule spots out: what's already on the plot, the sun, wind and views, the trees, the buried services, the local rules and finally access for the build. At each step you can draw the pool on your plan and see whether it still fits.

Start with what's already there

Before you draw any pool, you need a plan of the garden as it is: the plot boundary, the house with its doors onto the garden, the patio, the trees with the real diameter of their crown, the shed, and everything that's buried. If you're starting from scratch, the guide draw a floor plan of your house explains how to put the aerial photo down to scale and survey the walls.

In Architektor, the pool goes on the garden level and the pipes on the underground level. When one is active, the other stays visible, faded: exactly what you need to spot a clash.

The sun: the orientation that really matters

Water warms up in direct sunlight. In the UK and Ireland the sun is due south at midday, rises in the east and sets in the west. A pool to the south or south-west of the house gets the afternoon sun, when you actually use it. Put it north of the house and it spends part of the day in the house's shadow.

The catch is that shade changes with the seasons. At the latitude of Manchester, Leeds or Dublin, around 53° north, the midday sun climbs to about 60° at the end of June, but only about 37° at the equinoxes, in late March and late September. An obstacle then casts a shadow of:

In practice, a 2 m hedge shades just over 1 m at midday in June, but about 2.70 m in September. A house with its ridge at 8 m casts a shadow of nearly 11 m at midday in September, and much longer in the morning and evening. In London the sun is a little higher and shadows a little shorter; in Scotland they're longer. If you want to swim in May or September, that's the shadow that counts, not the July one.

To check on your own plot, take photos of the garden on a sunny day, around 10 am, 1 pm and 5 pm, and mark the shaded areas on your plan. The shadows on the aerial photo help too, but you don't know on what date or at what time it was taken.

Wind, views and privacy

Wind cools the water, speeds up evaporation and blows in leaves. Work out where it usually comes from at your place: a hedge or a wall on the exposed side shelters the pool, as long as it doesn't shade it at the wrong time. A hedge to the north doesn't block the sun; the same hedge to the south does.

Think about the view from the house too. Being able to see the pool from the kitchen or the living room makes it easier to keep an eye on children, and that's a safety point as well. Then look at what the neighbours can see: a pool under an upstairs window next door doesn't offer much privacy, and a hedge to screen it will take years to grow.

Trees: leaves, roots and full-grown size

A tree near a pool means leaves, pollen, blossom and fruit in the water, so more cleaning and a filter working harder. Conifers drop needles too. Roots can get in the way of the dig and, over time, damage pipes and structures.

Draw trees with the diameter of their full-grown crown, not today's. A young tree planted 3 m from the pool can cover it in fifteen years. In the tree's properties, set the crown diameter and the species: it keeps the plan honest. Avoid putting the pool under a crown, and allow for the tree's shadow as worked out above.

Buried services: find them before you dig

An in-ground pool needs a deep excavation, wider than the pool itself. Everything that runs underneath has to be known before the first bucket goes in: water supply, sewer, rainwater drainage, an electric cable to the shed or the gate, gas, fibre, land drains, septic tank, rainwater tank, soakaway.

Draw these services on the underground level, with their depth and diameter where you know them. The guide mapping underground pipes and cables explains how to find them and what to record. For public networks, check with the network owners before any digging: in the UK, the free LinesearchbeforeUdig service (lsbud.co.uk) covers many of them, but not all; in Ireland, ESB Networks and Gas Networks Ireland each run their own request service for maps.

The pool also has needs of its own:

• electricity for the pump, the filtration and often lighting or heating, to be installed by a qualified electrician in line with the rules in force;
• water for filling and topping up;
• a way to get rid of water from backwashing the filter and from draining the pool. Where it can go (foul sewer, surface water drain, soakaway) depends on your water company and your council: find out before you draw the route.

Mark these future services with the status “To build”: on the plan, you'll see straight away how long the trench needs to be.

The plant room and the route of the pipes

The filtration goes near the pool to keep the pipes short, but not just anywhere. A pump makes noise: keep it away from bedrooms, from the patio where you eat and from the neighbour's boundary. It has to stay accessible for maintenance, protected from water and frost.

On the plan, draw the plant room as a small area or a small building, then the pipes linking it to the pool and to the services. If the route crosses the whole lawn, the spot you've chosen may need a rethink.

Distances, planning and safety: the general rules

Rules vary between countries, regions and councils, and they change. What follows is the broad picture, to be checked every time with your local planning authority before you sign a quote.

• Distance to boundaries. Local rules, a planning condition or a restrictive covenant in your deeds can limit what you build near a boundary. Measure the distance on your plan from the edge of the pool, coping included, and take it to the council.
• Planning permission in England. On the Planning Portal, swimming pools come under the same permitted development rules as sheds and other outbuildings. At the time of writing, these rules mean, among other things, that nothing goes in front of the principal elevation of the house, and that extensions and outbuildings together can't cover more than half of the land around the original house. On designated land (conservation areas, National Parks and so on) a pool at the side of the house needs permission, and so does any pool in the grounds of a listed building. A pool hall or enclosure has its own height limits. If you want certainty, you can apply to the council for a Lawful Development Certificate.
• Elsewhere. Wales, Scotland and Northern Ireland have their own permitted development rules. In Ireland, the regulations set out what counts as exempted development, and your local authority can give you a formal declaration on whether your project needs planning permission.
• Safety. Some countries require a safety device on private pools (in France: a barrier, alarm, cover or enclosure). Ask what applies where you live. Even where nothing is required, a barrier or a safety cover prevents tragedies.
• Draining and discharges. Your water company or council may have rules on draining the pool and discharging backwash water. Ask at the same time as you ask about planning.

Bring your plan to scale when you talk to the council: a sketch with dimensions makes the conversation much more precise than a description.

Site access and spoil

It's easy to forget: a digger has to get in and lorries full of soil have to get out. Measure the narrowest point between the road and the spot you've picked (the drive, the side of the house, the gate) and give that figure to the groundworker.

The volume of soil is simple to work out. An 8 × 4 m pool with an average depth of 1.50 m means 8 × 4 × 1.5 = 48 m³ of soil in the ground, not counting the extra width of the dig and the base slab. Once dug out, soil bulks up and takes up noticeably more room. Decide in advance whether it will be taken away or reused to reshape the garden, and draw the temporary stockpile area.

Draw the pool and compare spots

Pick the Pool tool (P key): drag for a rectangular pool or click the corners for a free shape. In the properties, set the depth and the width of the coping; the approximate volume of water is shown. Then add the surround with the Area tool set to “Terrace”, and choose its finish: wood decking, travertine slabs, paving.

To compare, create a variant for each spot: “Pool south-west”, “Pool by the patio”, and so on. You can overlay two variants, the second one outlined in purple, to see what changes. If you've added your own API key, the AI assistant can also suggest spots based on your plan, but it's up to you to check its suggestions against the criteria in this guide.

Once you've decided, create a share link with “Garden and outdoor” for the pool builder or the landscaper. They open the plan without an account, measure it themselves and pin their comments in the right place.

Checklist before you ask for a quote

• The pool gets the afternoon sun in May and September, not just in July.
• No mature tree covers it, and no buried service runs underneath.
• The distance to the boundaries meets the local rules, checked with the council.
• The plant room is accessible, away from bedrooms and from the neighbour.
• The routes for electricity, water and drainage are drawn.
• The access for machinery is measured, and you've decided where the soil goes.
• You know which route applies: permitted development, a certificate or a planning application.

With these answers and a plan to scale, two pool builders will give you quotes you can compare, on the same basis.