Changing a bathroom's layout: what is and is not allowed

Why moving a fixture and moving a pipe are two different jobs

Sliding a wall-mounted basin thirty centimetres along the same wall, or swapping a bath for a shower in the same corner, generally just needs the existing supply and waste connections extended slightly. The floor stays closed, the wall stays closed, and the work is plumbing and tiling rather than construction.

Moving a toilet or shower to a different wall is a different matter, because the waste pipe has to follow it, and waste pipes rely on a fall towards the stack. In a panel block that fall often runs inside a concrete floor slab that was cast with the pipework already in it, so a new route means cutting the slab, which is not something to plan lightly.

In a 1930s wooden house in Kalamaja or Nõmme the floor structure is timber, which is easier to open but brings its own problem: the joists were not sized with a saw cut for a new drop in mind, and reinforcement may be needed once the cut is made.

When to tell the apartment association and when to ask its permission

In an apartment block the drains, stack and risers usually belong to the shared building systems even though they sit inside your flat's walls. Most apartment associations (korteriühistu) want to be told before any work touches those pipes, and many require written consent before a stack connection is altered or a new one is opened, because the change can affect flats above and below.

A layout change that stays within your own supply and waste connections, without touching the shared stack, is often something you only need to notify the board about, particularly if drilling or demolition will cause noise. Check your association's house rules for noise hours — many restrict loud work to weekdays and limit it further at weekends — and give neighbours reasonable warning regardless of what the rules say.

Where the wet zone moves onto a wall shared with a neighbouring flat, or work will affect the load-bearing structure, get the association's written agreement before work starts rather than after. This is worth doing even where the house rules are vague, since a dispute over unauthorised work is harder to resolve once tiles are already down.

When the change reaches the building register

The building register (ehitisregister) holds the official floor plans and technical documentation for the building. A layout change inside a bathroom does not always need to be recorded there, but a change that alters the position of plumbing risers, adds a new wet zone, or changes the room's use can count as the kind of change the register expects to know about.

Whether your specific change needs a notice or a permit is something only the Tallinn building authority or the register itself can confirm, since it depends on the building, the scope of the work and sometimes on decisions already on file for that address. Ask before work starts rather than assuming a small bathroom counts as too minor to matter.

We do not handle the paperwork side of this ourselves, but we can describe the planned layout change clearly enough — with sketches or photos — that you can put the right question to the association or the city and get a straight answer.

What waterproofing requires once the wet zone moves

Wherever water is used, the floor and the lower part of the walls need a continuous waterproof membrane that runs up behind the tiling and turns at every corner and pipe penetration without a gap. When the wet zone shifts to a wall or floor area that was previously dry, that membrane has to be built there from scratch, not patched onto the edge of the old one.

Floor drains need a fall towards the outlet of roughly one to two centimetres per metre, checked with a spirit level before tiling, not estimated by eye. Get this wrong and water sits in a corner instead of draining, which shows up as a smell or a damp patch long after the tiler has gone.

This is also where underfloor heating complicates things if the flat has it: cutting into a heated screed to move a drain risks damaging the heating cables or pipes, so the exact layout of the existing heating loop needs to be known before any cutting starts.

What is worth establishing before you decide anything

Before committing to a new layout, find out exactly where the stack and main waste pipe run, since the practical fall available for a new connection often decides which wall the toilet can realistically go on. A plumber can check this on site faster than a plan can be redrawn.

It is also worth checking your building's documentation for any existing record of the current layout, since a mismatch between what is on file and what is actually built can complicate a later permit question even if your own work is done correctly.

• Where does the waste stack run, and how much fall is actually available for a new pipe route
• Does the floor have underfloor heating, and where does the existing loop sit
• Is the wall you are moving fixtures onto load-bearing (we do not cut into these)
• What does the apartment association's house rules say about notice and noise hours
• Does the building register already hold a layout that matches what is actually built

What actually stays cheap and what turns into a bigger job

Moving a basin along the same wall, changing a bath for a shower in the same footprint, or repositioning a toilet by a few centimetres are all jobs that keep the existing drain routes and stay within ordinary plumbing and tiling work, priced from 45 € an hour for the plumbing and from 35 € per job for the tiling.

Moving a toilet or shower to a different wall, opening a concrete slab, or extending a stack connection is construction work with its own price, because it involves cutting, structural checks, and rebuilding the waterproofing layer properly rather than patching it. A full bathroom renovation of this kind is normally quoted as a fixed price from 3 500 €, agreed after seeing the space or photos of it.

The honest advice is to decide the layout question first, with the stack position and the association's view established, and only then get a fixed quote for the whole job — reworking a quote after the pipework turns out to be more involved than expected costs more than getting the facts straight beforehand.