Bathroom Renovation in London: Specification, Lead Times, and Cost Ranges

A bathroom renovation is deceptively complex. The room is small but involves more trades — and tighter coordination between them — than almost any other room in the house: plumbing, electrical, tiling, stone or joinery, and decoration, all working in a confined space in a precise sequence. A mistake in the sequence — tiling before the underfloor heating is commissioned, or capping off supplies before the sanitary ware is confirmed — sets the programme back by days.

This guide covers the specification decisions, trade sequence, and realistic costs for a bathroom renovation in a London property.

Scope definition

Before any trade is instructed, the scope must be fixed:

• —Is this a full strip-out and rebuild, or a refresh (reseal, regrout, replace fittings within the existing layout)?
• —Is the layout changing? If so, does plumbing need to be rerouted?
• —Is the floor being replaced? What is the floor structure beneath?
• —Is the ceiling being replaced, or are services above being reworked?
• —Is there a wet room element requiring a tanked floor?

A full strip-out and rebuild — the only approach that allows all services to be inspected and the structure to be tanked properly — is the right choice for any bathroom where the existing finishes are more than 15 years old or where the brief includes a significant change in finish quality.

Key specification decisions

Wall finish The options — large-format porcelain, natural stone (marble, travertine, limestone), or painted joinery with stone or tiled splashbacks — drive the cost and the trades involved significantly.

Large-format porcelain (600x600 and above, including 1200x600 and 3000x1000 slabs) is now the standard for high-specification bathrooms. It requires a plumb and flat substrate (rarely achievable in a London Victorian terrace without boarding out), and large slabs require specialist handling and fixing equipment. Budget for substrate preparation in the project costs.

Natural stone is warmer in appearance and texture but requires sealing, regular maintenance, and careful substrate preparation. Marble in a wet environment must be sealed effectively — unsealed marble in a shower absorbs water, stains, and delaminate at joints. Use a penetrating stone sealer on installation and maintain annually.

Floor finish and underfloor heating Underfloor heating in a bathroom adds around £600–£1,200 for an electric mat system (including thermostat and installation) in a standard bathroom. It is almost always worth specifying — tiled or stone floors without it are cold and uncomfortable.

The floor level is critical. The floor drain in a wet room or walk-in shower must be at the lowest point of the floor. This requires planning at design stage — the fall must be engineered into the screed or the substrate, not added as an afterthought.

Sanitary ware At the high end of the market, the specification is typically: freestanding bath (stone resin, cast iron, or copper), wall-hung WC and basin (Duravit, Villeroy & Boch, or equivalent), thermostatic shower valve (Hansgrohe Axor, Vola, or VADO), and stone resin or solid surface shower tray (or no tray — a wetroom).

The lead time for high-specification sanitary ware and brassware is 6–16 weeks. This must be ordered before first fix is complete — confirming what is being installed determines where water supply and waste positions go.

Brassware finish Chrome remains the most durable. Brushed nickel, matt black, and unlacquered brass are all popular but require more careful maintenance and are susceptible to water spotting. Plated finishes (PVD-coated) are more durable than lacquered; check the manufacturer's warranty.

Trade sequence

A full bathroom renovation follows this sequence:

1. 1.Strip out (remove all existing finishes, sanitary ware, pipework)
2. 2.Structural repairs (if required — rot, movement, lintel replacement)
3. 3.First fix plumbing (new supply and waste positions, pipework, underfloor heating)
4. 4.First fix electrical (extractor fan, downlight positions, heated towel rail supply, underfloor heating circuit)
5. 5.Boarding out (moisture-resistant plasterboard or tile backer boards)
6. 6.Tanking (waterproof membrane system to walls and floor in wet areas)
7. 7.Tiling or stone installation
8. 8.Second fix plumbing (sanitary ware, bath fill, shower valve)
9. 9.Second fix electrical (downlights, fan, thermostat, mirror light)
10. 10.Joinery (vanity unit, storage, mirrors)
11. 11.Siliconing and finishing

Any shortcut in this sequence — particularly tanking — stores up problems. A bathroom that leaks into the floor or through the wall to an adjacent room requires complete strip-out and rebuild to fix properly. Tanking done correctly takes 1–2 days and costs £300–£800; fixing water damage to the floor below costs multiples of that.

Realistic costs

These figures include all labour and materials but exclude sanitary ware and brassware (often specified and purchased separately by the client).

ASAAN has delivered bathroom renovation programmes across London's prime residential market. Our team manages the trade sequence and sanitary ware procurement to ensure the programme runs without costly rework.