Bathroom storage: dimensions, layout, mistakes

I allow 1.20 to 1.50 linear metres of usable shelving per person, roughly 70 % of it behind closed doors. For a couple, that means 2.50 to 3.00 linear metres, in other words a 100 to 120 cm vanity unit plus a 40 cm tall unit. For a family of four, you need 5.00 to 6.00 linear metres: a single vanity unit, however wide, will never be enough.

The linear metre of usable shelving is the right unit of measurement, not the number of cabinets. A 40 cm wide tall unit with five shelves gives 2.00 linear metres; a 120 cm vanity with two drawers gives only 2.40, part of which is lost to the trap. It is this calculation, not the look of the furniture, that determines whether the room will still be tidy in five years.

On top of this shelving, I always add a volume for bulk supplies: toilet paper, cleaning products, spare towels, and often the washing machine. This stock needs 0.30 to 0.50 m³ that nobody allows for on the original plans, and that ends up in the hallway.

This is the most common dimensional mistake. Cabinet depth is not a free choice: it is dictated by the basin and by the position of the trap. A 60 cm deep unit in a 4 m² bathroom steals 20 cm of circulation space for almost no storage gain, because you cannot reach the back of a deep drawer behind a bowl.

Two design rules I apply almost every time: drawers rather than doors under a basin, because a door forces you to bend down and turns the back of the cabinet into dead space; and moving the trap backwards or to one side, decided at plan stage with the plumber, to free up a genuine drawer. That offset costs next to nothing if it is anticipated, and becomes impossible once the tiling is up.

A double basin under 120 cm is not a comfort but a nuisance: two people knock elbows and the central storage is lost. Below that length, I prefer a single wide basin of 60 to 70 cm with a proper storage unit beside it. This is a trade-off I often go through when finalising the villa plan, before the partitions go up.

The niche in a shower wall is the most elegant storage solution and the riskiest. Done well, it lasts as long as the shower. Done badly, it becomes a point of water ingress into the next room, and the defect only shows after six to eighteen months, when the paint blisters on the other side of the wall.

Dimensions I use

• Common formats: 30 x 30 cm or 30 x 60 cm, 8 to 12 cm deep.
• Sill height: 100 to 120 cm above the finished floor, at arm's reach in the shower.
• Two stacked niches rather than one large one: one for tall bottles (30 cm clear height), one for soap and razor (18 cm clear height).
• Fall on the niche base: 1 to 2 % towards the inside of the shower, so water drains away instead of pooling behind the bottles.
• Tile setting out: I align the dimensions with the tile module, to avoid 2 cm cuts in the corners.

Waterproofing, in order

1. Masonry substrate or water-resistant board, never standard plasterboard.
2. Liquid waterproofing membrane (SEL) applied in two coats over the whole niche, base, sides and a 10 cm return all around, with reinforcing tape in every corner.
3. Treatment of the sill: the bottom edge of the niche is the weak point, it takes a corner tape and an upstand of waterproofing.
4. Tile or stone bonded with an adhesive suited to wet rooms.
5. Flexible sealant around the sill, never a cement joint in an internal corner.

I never place a niche in a wall backing onto a bedroom or dressing room unless liquid waterproofing is included in the works contract. On a shared wall, I prefer to build a 10 cm service lining, which also houses the supply pipes, or to move the niche onto the shower kerb wall. If the project affects the structure, the openings or the building footprint, it is no longer a simple interior renovation: the application goes through the Rokhas platform and requires an architect registered with the Order under Law 016-89, as I explain in the guide to the building permit in Morocco.

1. Choosing the furniture before drawing the plan. A unit bought in a showroom imposes its depth, its height and the position of its trap on a room that was not designed for it.
2. Doors instead of drawers under the basin: 30 to 40 % of the volume becomes unreachable.
3. A 60 cm deep unit in a room under 6 m², leaving less than 70 cm of passage in front of the basin. I keep 75 to 90 cm of clear circulation.
4. A carcass standing on the floor in the splash zone. A wall-hung unit can be cleaned, dries out, and makes the room feel larger.
5. A plain mirror where a mirror cabinet would have given 1.50 linear metres for free.
6. A shower niche with no liquid waterproofing, especially on a wall shared with a bedroom.
7. Too many open shelves. Beyond 30 % open, the room looks permanently untidy and everything gets coated in limescale.
8. No usable socket at basin height, or a socket placed inside a safety zone, which is prohibited.
9. Forgetting bulk supplies and the washing machine, then installing them in a hallway.
10. Ordering the joinery after the tiling without a joint site survey: you then discover 15 mm out of plumb and the unit no longer meets the wall.

What I check before drawing

I always start with three surveys: the actual ceiling height, the plumb of the walls, and the exact position of the plumbing and electrical connections. Then I list the items to be stored, category by category, and convert that into linear metres. The drawing comes last. This work is usually carried out as part of an interior fit-out commission, whose fee ranges I set out on the fees page: interior architecture at 10 to 20 % of the value of the works, and a preliminary assessment at 1,500 to 2,500 MAD if you would first like a costed opinion on the existing space. If you are unsure which professional to consult, the guide architect or interior architect sets out the distinction, and the architect in Rabat page explains the scope of my work.