Bathroom Renovation in City of Westminster

A like-for-like refit usually needs no permit in City of Westminster, but moving drainage, altering walls, or adding a new bathroom typically does under your local building rules — and electrical and plumbing work must be done by qualified or licensed trades in most countries. Ask your contractor to name the specific approval needed; see the country checklist on this page for what applies where you live.

Around 10-20% is normal, sometimes more where custom vanities or imported fittings must be ordered up front — in that case pay the supplier invoice share, not a round 50%. Hold 5-10% back until the room has been used for a week or two and the snag list (grout gaps, silicone, door alignment) is closed.

In rough order: whether you move plumbing (relocating the toilet or shower is the single biggest multiplier), the quality tier of tiles and fittings, bathroom size, waterproofing scope, and access (upper floors and apartment buildings cost more). Labour typically makes up 40-60% of the total, so a bigger bathroom does not scale cost linearly — fixture count matters more than floor area.

A bathroom renovation touches plumbing, electrics, waterproofing, tiling, and carpentry. A bathroom specialist or small contractor who coordinates all of it is usually worth the margin unless you have renovation experience — sequencing errors between trades (tiler before the plumber finished rough-in, for example) are the classic self-managed failure.

Strip-out, then first-fix plumbing and electrics (pipes and cables in walls), then substrate preparation and waterproofing, then tiling, then second-fix (toilet, vanity, taps, shower screen, lights), then silicone and snagging. If a quote or schedule doesn't follow this order, question it — out-of-sequence work is how leaks and redone tiles happen.

Buying your own toilet, vanity, and taps gives price control; buying through the contractor makes them responsible for defects, wrong sizes, and delivery timing. A common middle path: contractor supplies everything built-in or warranty-critical (shower valves, waste, membrane), you supply visible items like mirrors and accessories. Whoever supplies an item owns replacing it if it arrives damaged.

Checkatrade's 2025-26 guide puts a new bathroom including materials at £5,500-£8,000 with an average around £7,000; budget refits can come in near £3,000-£4,500 and large or high-end bathrooms run £14,000+. Fitting labour alone is typically £1,500-£4,000 depending on scope.

A straightforward refit takes about 5-10 working days; layout changes or first-floor drainage rework push it to two to three weeks. Book fitters ahead — good bathroom installers in most UK cities carry 4-8 week lead times.