Swimming pools and pool buildings in a garden
Class E of Part 1 expressly covers swimming pools within the curtilage of a house. The complications are the enclosure, the plant noise, the backwash water and designated land.
A swimming pool is one of the few things Part 1 of the Town and Country Planning (General Permitted Development) (England) Order 2015 names explicitly. Class E permits the provision, within the curtilage of a house, of any building, enclosure, swimming or other pool required for a purpose incidental to the enjoyment of the dwellinghouse. So an open outdoor pool in a rear garden, serving the household, is usually permitted development. What is not covered by that single sentence is the building over it, the heat pump that warms it, the water that comes out of the filter, and the position of all three on a constrained plot.
Three situations take a pool outside the right altogether. A house in the curtilage of a listed building, where Class E does not apply at all. A flat or maisonette, which has no Part 1 rights. And any pool intended for commercial or club use, which is not incidental to the enjoyment of the dwelling.
Pools as engineering operations
Excavating a pool is a building or engineering operation and therefore development under section 55 of the Town and Country Planning Act 1990. Class E is what makes it permitted, which means the Class E limits apply to the excavation as they do to a shed.
Two related operations are often forgotten. Disposing of the spoil on site, by spreading it to raise levels or forming a bund, can be an engineering operation in its own right and is not covered by the pool permission. And where the garden sits in Flood Zone 2 or 3, raising ground levels or displacing floodplain storage is a matter the authority and the Environment Agency will take an interest in, whatever the permitted development position.
Excavation near trees is the other recurring problem. A pool dug within the root protection area of a tree protected by a Tree Preservation Order or in a conservation area needs separate consent for the works affecting the tree, and permitted development rights do not displace that.
Pool buildings under Class E
The enclosure is where the limits bite. A building or enclosure under Class E has to satisfy all of the following:
- single storey, with a maximum eaves height of 2.5 metres
- a maximum overall height of 4 metres with a dual-pitched roof, or 3 metres with any other roof form
- a maximum overall height of 2.5 metres where any part is within 2 metres of the curtilage boundary
- no part situated on land forward of a wall forming the principal elevation of the house
- no verandah, balcony or raised platform
- use incidental to the enjoyment of the dwellinghouse
The 2.5 metre limit within 2 metres of a boundary is what usually forces a redesign, because a pool enclosure needs internal height for headroom above the water and a plant space, and a 2.5 metre overall height leaves very little. Moving the structure two metres off the boundary buys a metre and a half of height, which is almost always the better trade.
A changing room, shower and WC inside the pool building remains incidental. A kitchen, a bedroom or a separate letting takes it towards a separate dwelling, which is the same line examined in outbuildings with a shower room or kitchenette and in annexes and the single planning unit question.
The 50 per cent curtilage calculation
Class E is not available where the total area of ground covered by buildings, enclosures and containers within the curtilage, other than the original dwellinghouse, would exceed 50 per cent of the total area of the curtilage excluding the ground area of the original house.
Two points matter in doing that sum. The baseline is the original dwellinghouse as built or as it stood on 1 July 1948, so later extensions do not reduce the curtilage figure but existing outbuildings do count towards the 50 per cent. And the test is expressed as the area covered by buildings, enclosures and containers, which leaves an open question about whether an uncovered pool counts towards it at all.
Authorities take different views on that, and I would not rely on either reading without asking. Where the plot is tight enough for the answer to matter, put the calculation to the council in writing with a measured plan, or apply for a certificate of lawfulness of proposed use or development under section 192 of the 1990 Act. A roofed pool enclosure plainly counts, so on a small garden the covered option is the one that exhausts the allowance.
Plant noise and its position
Pool plant runs for hours at a time and often in the early morning. The filtration pump, the heat pump and any air handling for an enclosure are all continuous sources, and the nearest bedroom window is usually the neighbour's.
The assessment, where one is needed, follows BS 4142:2014+A1:2019, comparing the rating level of the plant with the representative background sound level at the affected facade, with corrections for tonality and intermittency. Authorities typically want the rating level at or below background, and lower again at night.
Practical measures, in order of usefulness:
- Site the plant on the house side of the garden rather than against the neighbour's boundary.
- Enclose it in an acoustic housing or a plant room with lined ducts rather than a timber box, which does little.
- Mount pumps and compressors on anti-vibration pads, with flexible pipe connections.
- Set a timer that keeps filtration and heating out of the night period.
- Choose a unit with a lower sound power level at the outset, because the data sheet figure is the lowest-cost decibel available to you.
Where the heating is an air source heat pump, that unit has its own permitted development right under Part 14 with its own conditions, including a volume limit for the outdoor compressor unit and restrictions on designated land. Those conditions have been amended more than once, so read the current text rather than an older summary. Where permission is needed, a Noise Impact Assessment with a background survey covering the quietest period the plant will run is what answers the environmental health consultation.
Drainage and backwash disposal
Pool water is not clean water. Filter backwash carries chlorine or bromine, stabiliser and filter media, and emptying a pool releases a large volume in a short time.
The orthodox route is a connection to the foul sewer, agreed with the sewerage undertaker, at a controlled rate. Discharge to a surface water drain, a soakaway, a ditch or a watercourse is a different matter, because chlorinated water is harmful to aquatic life and such a discharge may require an environmental permit or be prohibited outright. Dechlorination before discharge, and holding the water until residual levels have fallen, are the usual conditions of acceptability.
Show the proposed arrangement on the drainage drawing: the backwash connection, the rate, the route and the point of discharge. On a septic tank or package treatment plant, a pool backwash can overwhelm the system, so the volumes need checking with the manufacturer before the pool is dug.
Lighting and boundary effects
Underwater and surround lighting is the complaint that arrives after the pool is in use. Specify downward-directed fittings, keep luminaire intensity low, avoid uplighting of trees and boundaries, and set a curfew for the lighting rather than for the pool.
Where the garden adjoins open countryside, a hedgerow or a watercourse, lighting has an ecological dimension as well. Bats commute along linear features, and continuous lighting of a boundary hedge can sever a flight line. A lighting layout that leaves the boundaries dark costs nothing extra at design stage.
Designated land restrictions
On designated land, which means a conservation area, a National Park, a National Landscape or a World Heritage Site, Class E is narrowed in one important way: no building, enclosure, pool or container may be situated more than 20 metres from any wall of the house. On a large garden that puts the pool close to the dwelling whether the design wants it there or not.
Within the curtilage of a listed building, Class E does not apply at all, so a pool and any enclosure need planning permission, and works affecting the listed building itself or a curtilage structure need listed building consent. A pool in the setting of a listed building also engages the duty to have special regard to its setting, which usually means a sunken pool with a stone or dark finish and no raised surround.
Where permission is needed, a short Planning Statement covering the incidental use, the plant position and noise, the drainage route and the landscape treatment answers most of the officer's questions in one document. PlanScope drafts it from your answers about the property and flags the facts it does not hold, and you can enter your postcode on the home page to see what else a householder application is likely to need.
This is general guidance, not legal advice; check the position with your local planning authority or a qualified professional before relying on it. PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval.
Frequently asked questions
Do I need planning permission for a swimming pool in my garden?
Usually not for an open outdoor pool. Class E of Part 1 of the GPDO expressly permits a swimming or other pool within the curtilage of a house where it is incidental to the enjoyment of the dwelling, subject to the Class E limits. Listed building curtilages, flats and commercial use fall outside the right.
How high can a pool building be under permitted development?
Single storey, with eaves no higher than 2.5 metres and an overall height no more than 4 metres with a dual-pitched roof or 3 metres with any other roof. Where any part is within 2 metres of the boundary, the overall height limit drops to 2.5 metres, which usually forces the building further in.
Does a swimming pool count towards the 50 per cent curtilage limit?
The test refers to the area covered by buildings, enclosures and containers, so whether an uncovered pool counts is arguable and authorities differ. A roofed pool enclosure plainly counts. Where the plot is tight, put the calculation to the council in writing or apply for a certificate under section 192.
Where can pool backwash water be discharged?
The orthodox route is a controlled connection to the foul sewer agreed with the sewerage undertaker. Discharge to a surface water drain, soakaway, ditch or watercourse may need an environmental permit or be prohibited, because chlorinated water harms aquatic life. Dechlorination before discharge is usually required.
Can I put a pool in my garden in a conservation area?
Class E still applies in a conservation area but no building, enclosure or pool may be situated more than 20 metres from any wall of the house. That often conflicts with where the pool would naturally go on a large plot, in which case a planning application is needed for the preferred position.
Sources and further reading
This article is general guidance about the planning system in England and, where stated, the rest of the UK. It is not legal or professional advice. Check your local planning authority’s validation requirements and take professional advice for your specific site.