Projects

Bathtubs for Apartment and Multi-Unit Projects

A bathtub is the largest single object that goes into an apartment bathroom, and the least forgiving: its drain is where the factory put it, its weight sits on someone else's floor, and it has to fit through every door between the truck and the room. Multi-unit projects handle this by deciding early, once per apartment type, and coordinating the rest from the drawing. This guide sets out how to specify, order and receive bathtubs on that basis.

Published September 23, 2026Last updated September 23, 2026

The short answer

Quick Reference

Point 01: One tub model per apartment type; compact soaking or built-in formats where the bathroom is tight.
Point 02: Floor loading on upper floors is confirmed by the project's structural engineer before the model is fixed.
Point 03: Drain and overflow positions are fixed at the factory, so the rough-in must match the approved drawing.
Point 04: Check the delivery route, doors, lifts and corridor turns, before the order is placed.
Point 05: Label each tub for its unit, deliver in phases by floor, keep the protection on until handover.

Compact upright soaking tub with floor-standing filler and stool

Start here

Two Things Go Wrong, and Both Are Avoidable

On a multi-unit project a bathtub fails in one of two ways: it does not meet its rough-in, or it cannot reach its room. Neither is discovered at the factory. The first is a drawing problem, solved by fixing the model early and roughing in to its approved drawing; the second is a route and sequence problem, solved by checking the path and delivering by floor. Everything else in this guide serves those two ends.

Fix the model per unit type before rough-in begins
Rough in to the approved drawing, not the other way round
Check the route and sequence the delivery by floor

One Model per Unit Type

Decide one tub model for each apartment type and hold to it. A single model per type means one drawing for the plumber, one rough-in template, one crate size for the route check and one set of spares for the building manager; every exception multiplies all four. Where the bathroom is tight, the format follows the plan. A compact soaking tub, shorter than a conventional tub and used sitting rather than lying, fits a studio bathroom where a full-length tub would not; a built-in solid surface tub set between walls or into a deck uses the room's own structure to carry the edge and gives the tiler a clean line to finish to. Larger units can take a freestanding tub where the plan shows clear floor around it. Whatever the format, fix the filler type at the same time, deck-mounted, wall-mounted or floor-standing, because it decides where the supply pipes must be.

One model per apartment type; exceptions multiply drawings and spares
Compact soaking tubs where the floor is short
Built-in tubs where the walls or a deck carry the edge
Filler type fixed with the model

Structure and Rough-In

Built-in bathtub installation drawing with drain and access panel

A filled tub with a bather in it is a concentrated load on a small footprint, and a cast solid surface tub is heavier than a thin-shell tub of the same size. On upper floors, the floor loading is confirmed by the project's structural engineer before the model is fixed, using the tub's drawing; that is a project decision, not one a supplier can make for it. The drain and overflow positions on a solid surface tub are cast and drilled at the factory and cannot be moved on site, so the rough-in follows the approved drawing: the drain center referenced to two walls, the trap position and depth, the overflow height, and for a built-in tub the access panel through which the trap is reached later. WNS Global provides a dimensioned drawing for approval and releases production after the golden sample is approved; the plumber roughs in to that drawing, and the first tub of each type is checked against it before the rest are fitted.

Upper-floor loading confirmed by the project's structural engineer
Drain and overflow fixed at the factory; rough-in follows the drawing
Access panel for the trap on built-in tubs
First tub of each type checked against the drawing before the rest

Delivery and Protection

A worker moving crate-packed goods with a pallet truck in the warehouse

Before the order is placed, walk the route: the building entrance, the corridor turns, the lift car and its door, the stairwell if there is no lift, and the bathroom door itself. Compare each against the crated and uncrated tub dimensions on the drawing. A tub that arrives before the door frames and corridor finishes are in has an easier route, which argues for delivering by floor once the structure is closed but before finishes go in, and then protecting the tub through the rest of the fit-out. Each crate is labeled with block, floor, unit number and model code so it goes to the right room unopened, and phased shipments follow the program floor by floor. Keep the factory protection on and add a rigid cover: a bathtub is the most convenient table on a building site, and most handover damage is done by other trades. Inspect and record each tub on arrival, and hold spare waste and overflow fittings on site.

Route check against crated and uncrated dimensions before ordering
Deliver by floor after the structure closes, before finishes
Crates labeled by block, floor, unit and model code
Protection on and a rigid cover until handover

Common questions

Apartment Bathtub Questions

Answers to the checks buyers most often make before using this guide for a project or sourcing decision.

Which bathtub format suits a small apartment bathroom?

A compact soaking tub where the floor is short, or a built-in solid surface tub set between walls or into a deck. Freestanding tubs belong in larger units with clear floor around them.

Do upper-floor bathtubs need a structural check?

Yes. Floor loading is confirmed by the project's structural engineer before the model is fixed, using the tub's drawing. It is a project decision, not the supplier's.

Can the drain position be changed on site?

No. Drain and overflow positions are cast and drilled at the factory. The rough-in follows the approved drawing, so raise any constraint on the drain position before the drawing is finalized.

How do we get a bathtub into an upper-floor apartment?

Walk the route before ordering: entrance, corridor turns, lift, stairwell and bathroom door, checked against the crated and uncrated dimensions on the drawing. Deliver before finishes narrow the route.

What are the lead time and minimum order for a project?

Lead time is subject to the current production schedule, typically 45–60 days, with phased delivery by floor. The minimum order is confirmed by quotation for the specific model and finish.

Does WNS Global hold certifications for bathtubs?

No. WNS Global does not hold third-party certifications. Any requirement of the destination market is confirmed per model before the order is placed.

A bathroom vanity packed in a timber crate with its paperwork

In short

Decide Early, Rough In to the Drawing, Deliver by Floor

One tub model per apartment type, compact soaking or built-in where space is tight, with the filler type fixed at the same time. Floor loading confirmed by the structural engineer, drain and overflow roughed in to the approved drawing. Route walked before ordering, crates labeled by unit, delivery phased by floor, protection on until handover.

One model and one filler type per unit type
Structural check on upper floors before the model is fixed
Rough-in matches the factory-fixed drain and overflow
Route, labeling, phasing and protection planned with the program

Verification sources

Official Sources and Further Reading

This guide explains planning concepts, not a substitute for the approved product drawing, installation instruction or requirement adopted by the authority having jurisdiction. Confirm those project-specific documents before ordering or installing.

Specifying bathtubs for a multi-unit project?

Talk to WNS Global

Send the unit type schedule, the bathroom plans and the build program, and we will propose a model per type, return drawings for approval and plan the delivery phasing with you.