Bathroom Renovation London: Costs, Timeline, and Planning Guide

Cost tiers in 2026

In London, bathroom renovations split fairly cleanly into three tiers. The numbers below are for a typical four square metre family bathroom in a South London terrace or semi. Smaller en suites cost about 20 percent less. Larger or split layout bathrooms cost more.

Basic refresh: £3,000 to £5,000

A like for like swap. New suite, new tiling on the walls and floor, paint, lighting, and a basic extractor. You keep the existing layout, the existing waste runs, and the existing pipework. This is what most landlords budget for between tenancies, and it is plenty for an investment property or a starter renovation in a flat. Expect mid range fixtures from Bristan, Mira, or Methven, and ceramic or porcelain tiles in the £25 to £45 per square metre range.

Mid range: £6,000 to £9,000

The most common tier we fit. The layout might shift slightly (moving the shower to a better position, losing the bath in favour of a walk in shower, fitting a wall hung vanity unit). Fixtures step up to brands like Hansgrohe, Grohe, or Roca. Tiling is better quality and might involve a feature wall or porcelain in larger formats. You get a proper quiet extractor, an electric heated towel rail or a dual fuel one, and decent LED lighting with separate circuits.

Luxury: £12,000 and up

Full design led renovation. Layout changes (sometimes including stealing a square metre from the bedroom or hallway). Underfloor heating. Concealed cisterns and wall hung WCs. Marble or large format porcelain. Brassware in matt black or brushed brass from Crosswater, Vola, or similar. Digital shower valves with smart controls. Bespoke vanity and storage. Full mood lighting on dimmers. £15,000 to £20,000 is realistic for a high spec family bathroom in 2026 once you include design fees.

Whichever tier you sit in, the gap between a good install and a poor one is bigger than the gap between fixtures from one brand and another. Tiles laid badly or waterproofing missed will cost more in three years than the saving you made on cheaper fixtures.

Week-by-week timeline

A standard four square metre bathroom takes seven to ten working days in 2026. Allow twelve days if you are changing the layout. Here is what each phase looks like.

Days 1 to 2: strip out

Tiles come down, the suite comes out, the floor is lifted if needed. We protect the rest of the house with dust sheets and corner guards on the route from the front door to the bathroom. By the end of day two the room is back to bare brick or stud, plumbing pipework is exposed, and the first fix can begin.

Days 3 to 4: first fix plumbing and electrics

New pipework runs to the new positions for taps, shower, toilet, and basin. Electrical first fix runs cables for lighting, extractor, towel rail, and shaver socket. If you are adding underfloor heating, the cables go down at this stage. We pressure test the pipework and notify building control if any of the electrical work falls under Part P notification.

Days 5 to 6: prep, plaster, tank

Walls are skim plastered or boarded. Wet areas get a tanking membrane (a flexible waterproof layer behind the tiles). The floor goes down and gets primed. Underfloor heating is screeded over and left to cure.

Days 7 to 9: tiling

Floor first, walls second. Larger format tiles take longer to lay but look better and have fewer grout lines to clean. We grout, allow it to cure, then silicone the perimeters. This phase needs patience. Rushing the curing time is what causes hairline cracks in grout six months down the line.

Day 10: second fix

The suite goes in. Taps, shower, toilet, basin, towel rail, lighting, extractor. The room comes alive in a single day. We test everything for leaks and run the shower for half an hour while we tidy.

Day 11: snagging and clean

We walk through with you, mark up anything that needs adjusting, fix it, then deep clean the room and dispose of the waste. You get a completion pack with appliance manuals, warranty registrations, and tile spares.

Planning permission rules

For a standard bathroom renovation inside an existing footprint, you do not need planning permission. Refitting a bathroom counts as a repair or maintenance under permitted development rights.

You may need permission if any of the following apply:

• The property is in a conservation area and you are altering external features (windows, soil pipes that route up the front of the house)
• The property is listed (any internal change usually needs listed building consent, which is separate from planning)
• You are adding a new bathroom by extending the property or converting a loft
• You are converting a single dwelling into multiple flats

For a flat, check whether your lease requires landlord (freeholder) consent for alterations. Most long leases in London require written consent for any work that affects shared services, soundproofing, or floor coverings. Getting consent retrospectively is harder and more expensive than asking before you start.

Choosing fixtures

The first rule: choose brands you can buy spares for. A statement tap from an obscure boutique brand looks great until the cartridge fails in three years and you cannot get a replacement. Stick with Hansgrohe, Grohe, Crosswater, Roca, Duravit, Vado, or Methven for fittings you can service.

For showers, thermostatic valves are mandatory in 2026 for safety and water saving. A digital shower (Mira Platinum, Aqualisa Quartz) is worth the extra spend if you have multiple users with different preferred temperatures.

For toilets, wall hung WCs with concealed cisterns look cleaner but rely on the frame being solid. Cheap frames from generic suppliers wobble within a year. Geberit and Grohe Rapid frames are the gold standard.

For tiles, larger formats look more expensive than they are, hide grout lines, and are easier to clean. Avoid very dark grout if you have hard London water, because limescale shows on it badly.

Finance options

Most bathroom renovations are funded by savings or a small remortgage. For mid range jobs we can offer third party finance via Novuna or Tandem, with options ranging from 0 percent over 12 to 24 months on smaller jobs to 9.9 percent APR over 5 to 10 years.

For landlords, bathroom renovation costs are usually deductible against rental income as a repair if you are replacing like with like. Adding an en suite where there was no bathroom before counts as a capital improvement and offsets against capital gains rather than income. Speak to your accountant for specifics.