What decides the cost of a bathroom renovation?

Why does a small bathroom cost more per metre than a large room?

Owners are often surprised that a bathroom of a few square metres can rival a much larger living room in the quote. The reason is concentration. A living room might need floor, paint and a few electrical points. A bathroom needs strip-out of tiles and sanitaryware, new supply and waste pipes, waterproofing in the wet zone, tiling or another finish on walls and floor, ventilation, lighting, and the fitting of every sanitary item and tap.

Most of these tasks have a fixed component that does not shrink with the room: the plumber still has to come, the waterproofing still needs its layers and curing, the fitter still connects the same number of items. That is why dividing a bathroom quote by its floor area gives a misleading number, and why we never quote bathrooms that way.

Which lines appear in a Spanish bathroom quote?

A complete bathroom quote normally contains these lines, each with unit and quantity:

• Removal of sanitaryware, wall and floor tiles, with debris loading and disposal (m² or PA).
• Supply pipework renewed to each point (ud per point, or ml).
• Waste pipework and connection to the building’s stack (ud or ml).
• Waterproofing of the shower area or the whole floor (m²).
• Screed or levelling for the floor and the shower fall (m²).
• Wall finish: tiles or a seamless coating (m²).
• Floor finish (m²).
• Electrical points, extractor and lighting, by an authorised partner installer (ud).
• Supply and fitting of shower tray or drain, screen, WC, basin, taps (ud).
• Final clean.

If one of these is missing from a quote you are comparing, ask whether it is excluded or simply hidden in another line. The itemised quote page shows how such lines are written.

How much does the shower choice change the quote?

Replacing a bath with a shower is the single most requested bathroom job on the coast, and the shower type is one of the biggest cost switches. A raised shower tray placed where the bath was, using the existing drain position, is the simplest version. A level-access shower, flush with the floor and with a linear drain, needs the floor lowered or built up to create the fall, more waterproofing and careful detailing at the threshold.

Whether a level-access shower is possible at all depends on the height available for the drain fall, which we check on the visit. When it is feasible, it adds lines rather than replacing them. The bathroom site reformabanosmalaga.eu explains the options from a design point of view; here we focus on what each one does to the quote.

Tiles or a seamless finish: what changes in the cost?

Tiles and seamless finishes (often called microcement, although the systems vary) are priced very differently. With tiles, the material can range widely by format and quality, and large formats need a flatter substrate and more careful handling. Laying cost rises with cuts, niches and patterns.

A seamless finish is applied in several coats over a prepared substrate. Material cost is usually less of a variable than labour and preparation: the walls must be sound, and the system must be suitable for wet areas. It can sometimes go over existing tiles, which reduces strip-out, but only if the base is stable — something we only confirm on site.

Neither option is automatically cheaper. A good quote shows the finish as its own line, with the substrate preparation separated, so you can compare like with like.

Scenarios without figures: three bathrooms of about 4 m²

Bathroom 1 – refresh. Pipes renewed some years ago, layout stays, bath replaced by a tray in the same position, new wall tiles to full height, new WC and basin. Lines are mostly strip-out, tiling and fittings. Plumbing is limited to reconnections.

Bathroom 2 – full renewal. Original galvanised pipes, cast-iron waste, uneven floor. Same visible result as bathroom 1, but the quote now has full supply and waste chapters, screed, and waterproofing over the whole floor.

Bathroom 3 – redesign. Level-access shower with linear drain, WC moved to the opposite wall, seamless finish, built-in niche and indirect lighting. Every chapter of bathroom 2 plus extra drainage work, more electrical points and more detailed finishing.

Same size, three different quotes. The difference lies in the decisions, not in the square metres.

What is often missing from a cheap bathroom quote?

When one bathroom quote is much lower than the others, the gap is usually explained by what is not there. The most common omissions:

• Waterproofing listed vaguely or not at all. It is invisible once tiled, which is exactly why it matters.
• Supply and waste pipes not renewed, only reconnected to the old ones.
• Debris disposal left out, or assumed to be your problem.
• Sanitaryware and taps excluded, with a note saying “supplied by the owner”.
• Electrical work missing, although new lighting and an extractor are expected.

Our blog post on cheap versus expensive renovations looks at how to tell a lean quote from an incomplete one.

How do we prepare a bathroom quote?

Send photos of the bathroom from the door and from inside, close-ups of the bath or shower, the toilet and the basin, and the approximate dimensions. If you can, add a photo of any visible pipes and of the floor at the threshold, which tells us a lot about levels.

From that we give a first assessment of the likely lines and the open questions. On the visit we measure, check the drain position and the height available, look at ventilation and agree finishes. The quote you receive lists every line with its unit and quantity and shows VAT separately. If you have a quote from another builder, we are happy to compare structures with you — see our guide on comparing quotes.