Can a deep tub go on a timber floor?

Often, yes, after a structural check. We calculate the load of the filled tub on the joists and, where needed, add reinforcement designed by a structural engineer, or choose a smaller or lighter tub.

How do I know whether my building is a monument?

In the Netherlands, national and municipal monuments are listed in public registers, and in Spain the town hall's catalogue shows protected buildings. We look up your address before planning, because it decides which permit applies.

Do I need my comunidad's permission for a bathroom renovation in Spain?

You must inform the comunidad's representative before the works. If the works affect shared elements, the structure or the facade, the comunidad's agreement is needed. We prepare a description of the works for the administrator.

How long does a renovation in an old building take?

A full Japanese bathroom usually takes three to six weeks on site. In old buildings, add time for structural checks, any reinforcement and permits, especially for monuments or catalogued buildings. We include this in your schedule.

Japanese Bathroom Renovation in Old and Listed Buildings

Japanese bathroom renovation in old buildings: canal houses, Eixample fincas and listed homes

Many of the homes where people dream of a Japanese bathroom are old: Amsterdam canal houses, Hague townhouses, modernist fincas in Barcelona's Eixample or classic buildings in Madrid's Salamanca district. They are beautiful places for a deep tub and a wet room, but they come with timber floors, old pipes, narrow stairs and permits. This guide explains how we plan around them.

Updated October 2026

Start with the structure

Old buildings rarely have the concrete slabs of a new flat. Canal houses and many pre-war Dutch homes rest on timber joists; Barcelona's Eixample fincas typically have floors of beams with ceramic vaults; classic Madrid buildings are often built on timber or steel joists. A filled Japanese tub can put several hundred kilos on about one square metre, and a wet room adds screed, tiles and water. So the first step of every project in an old building is a structural check: we open up where possible, look at the span, condition and direction of the beams, and calculate the load of the filled tub. If the floor needs it, a structural engineer designs reinforcement, or we choose a smaller, lighter tub or a position closer to a load-bearing wall. We never assume.

Dutch monuments and the omgevingsvergunning

A bathroom renovation inside a non-listed Dutch home, without structural changes, usually needs no permit. Monuments are different. Changes to a national or municipal monument generally require an omgevingsvergunning, and in Amsterdam that can include the interior; the city recommends talking to its heritage specialists before applying through the Omgevingsloket. The Hague states that almost every change to a monument needs a permit, although some changes to municipal monuments can be permit-free under its 2024 heritage ordinance. Rotterdam offers a free concept request to test a plan, and Utrecht's Commissie Welstand en Monumenten advises on applications. A protected cityscape (beschermd stadsgezicht) mainly affects exterior work. Since work on a monument may only start once the permit allows it, we check your address early and build that time into the schedule.

Barcelona: three types of minor works

Barcelona's ordinance on building works (ORPIMO) sorts minor works into three types. Interior works in a dwelling that do not change the layout, structure or facade, in a building that is not catalogued or protected, follow the simplest regime (assabentat): you notify the Ajuntament before starting, without technical documents, and work can begin the next day. If the renovation changes the layout without touching the structure, for example moving a non-load-bearing bathroom wall to make room for a washing area, it becomes a type II minor work, filed with technical documentation. Catalogued and protected buildings, which are common in the Eixample, follow stricter procedures. The Ajuntament recommends a prior consultation (consulta prèvia) in its virtual office, and we prepare the documents for each project.

Madrid and Valencia: when a declaración responsable applies

According to the Ayuntamiento de Madrid, some interior work needs neither a licence nor a declaración responsable, such as replacing tiles, floors and other finishes or renewing installations with similar ones, provided the building has no architectural protection. When the renovation goes further, such as redistributing the bathroom, the usual route is a declaración responsable urbanística, and certain works need a licence. Many fincas in Salamanca and Chamberí are protected, so the procedure depends on the address. In Valencia, the Ajuntament has a specific declaración responsable for renovation works in a dwelling in a non-catalogued building, filed before work begins with the related taxes paid in advance; catalogued buildings generally follow a licence procedure. We confirm the route for your address during the survey and prepare the paperwork.

Your VvE or comunidad

In an apartment building, the owners' association is part of the plan. In the Netherlands, the deed of division and the VvE rules decide what needs approval; work on shared drains, supply pipes, load-bearing walls or floors usually does, and some buildings set acoustic requirements for new floor finishes, which matter for a tiled wet room. In Spain, article 7.1 of the Ley de Propiedad Horizontal lets an owner alter the installations of their own flat only if the building's safety, structure, exterior and the rights of other owners are not affected, and requires the owner to inform the comunidad's representative before the works. Anything affecting shared elements, such as the drain stack or the structure, needs the comunidad's agreement. We prepare drawings and a clear description of the works for the VvE board or the administrator.

Old pipes, hidden materials and ventilation

Behind the tiles of an old bathroom there is often more history than expected. In the Netherlands, lead drinking-water pipes occur mainly in buildings from before 1960, and the government advises owners to have them traced and replaced. Dutch homes built before 1994 may contain asbestos; before renovation an inventory by a certified firm is generally required, and removal is notified to the municipality in advance. In Spain, old fibre-cement drain stacks or panels may contain asbestos, and only companies registered in the RERA with an approved work plan may remove them. During a renovation we replace old drains and supply pipes in the bathroom, and we add mechanical extraction to the outside, so the moisture from a deep, hot bath never reaches old brickwork, timber or plaster.

Getting materials in, and how the project runs

Steep Dutch stairs, Eixample stairwells and Madrid buildings without a lift make delivery part of the design. We measure stairs, doors, lifts and windows during the survey. A tub can come in by the stairs, in sections, through a balcony, or through a window with a canal house's hoisting beam or a furniture lift, and a hinoki tub can be made to fit. Where a lift needs space on the street, we coordinate the municipal arrangements. A Japanese engineer leads the project from survey to handover, every hidden layer is photographed, and wet areas are flood-tested for 24 hours before tiling. Indicative prices for a Japanese bathroom start at €24,000 including VAT; old buildings vary widely, so you receive a fixed quote after the survey, with permit time built into the schedule.