Downstairs Toilet Installation Cost UK 2026

Installing a new downstairs WC (cloakroom toilet) in 2026 costs £1,500–£4,000 — the most expensive toilet job because of plumbing, electrics, ventilation and partitioning.

Quick answer

Typical UK price range: £1,500–£4,500. Typical time: 5–10 days.

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Key points

  • £1,500–£4,000 typical
  • Often built under stairs
  • Plumbing + electrics + extractor required
  • Adds 2–4 % to property value

Cost breakdown

Item Low High
Toilet + basin £300 £900
Plumbing (incl. soil) £600 £1,500
Electrics + extractor £300 £700
Stud wall + tiling £300 £900

Cost by UK region

Region Typical cost
London £4,050
South East £3,750
South West £3,300
Midlands £3,000
North England £2,700
Scotland £2,850
Wales £2,700

How to save money

  • Locate near existing soil stack to avoid macerator
  • Always specify a quiet extractor fan
  • Wall-hung pan + basin saves visual space under stairs

How to find a trusted tradesperson

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FAQs

Do I need planning permission for a downstairs toilet?

No — interior remodelling is permitted development. Building regs sign-off needed for the plumbing/electrics.

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Disclaimer: Prices are guide ranges based on 2026 UK market data. Get quotes from local tradespeople for accurate pricing.