In 40 seconds
Building a swimming pool in the UK covers a wide range. A professionally installed above-ground pool is usually around £5,000–£10,000, while an in-ground outdoor pool typically runs £30,000–£100,000+ depending on size, shell and ground conditions. An indoor pool costs more again — often £85,000 to well over £200,000 — because it needs a building, ventilation and dehumidification. Running costs depend mostly on heating: an outdoor pool warmed by a heat pump can be roughly £200–£500 per season, gas heating much more at £800–£3,000 per season, and an indoor pool around £500–£600 per month year-round. Most outdoor pools count as permitted development and need no planning permission, but indoor pool buildings, listed properties and conservation areas often do. The honest answer is always a range, because it depends on your site, pool type and how you heat it.
Most pool guidance is published by companies that build them, so the numbers tend to be optimistic and the running costs glossed over. The pages below give honest cost ranges for installing and running a pool, compare indoor and outdoor fairly, explain which heating works out lower in cost, and set out the planning rules — before you take a single quote.