Small Projection Toilet: How to Save Space with the 59cm K80

A small bathroom does not necessarily require a basic toilet. The right small projection toilet can create more usable floor space while still providing comfortable seating, reliable flushing and modern bidet functions.

The BBbidet K80 measures 590mm from front to back, making it a compact option for narrow bathrooms, powder rooms, en-suites and apartments. It combines a short body with an integrated bidet, heated seat, warm-water washing, warm-air drying and automatic flushing.

Before choosing any compact toilet, however, check more than its overall length. Projection, outlet position, rough-in measurement, water supply and electrical access all affect whether it will fit.

Quick Answer: Is 590mm a Small Projection Toilet?

Yes. At 590mm from front to back, the K80 is a short-projection toilet designed for bathrooms where every centimetre of floor space matters. Its compact body measures 590 × 380 × 480mm and is available for both P-trap wall-outlet and S-trap floor-outlet installations. The outlet type and rough-in measurement must still be confirmed before ordering.

What Is a Small Projection Toilet?

Toilet projection is the distance the toilet extends into the room from its rear installation point to the front of the bowl.

There is no universal measurement that officially defines a small or short projection toilet. As a practical guide:

• Toilets below 600mm are generally considered very compact.
• Models around 600–650mm are commonly described as compact.
• Many conventional toilets extend approximately 650–700mm or more.

Always use the exact product dimensions rather than relying on labels such as “compact,” “short” or “space-saving.”

At 590mm deep, the K80 falls below the 600mm reference commonly used for very compact toilets. Its complete dimensions are:

• Depth: 590mm
• Width: 380mm
• Height: 480mm
• Imperial dimensions: approximately 23.2 × 15 × 18.9 inches

These measurements should still be checked against the finished bathroom—not an unfinished wall or an estimate taken before tiling.

How Much Space Can a Short Projection Toilet Save?

A difference of 50–100mm may appear small on a specification sheet, but it can materially improve a tight bathroom.

Reducing projection can provide:

• More knee room in front of the toilet
• A wider route between the toilet and basin
• Better clearance for a shower screen
• More room for a door to open
• A less crowded appearance

For example, replacing a toilet with a 680mm projection with a 590mm model creates approximately 90mm of additional front clearance, assuming both products can use the same installation position.

Actual savings depend on the outlet, connectors and finished wall. A compact pan installed with an exposed pipe extension may not save as much space as its listed dimensions suggest.

Is the K80 Suitable for a Small Bathroom?

The K80 is designed for bathrooms where front-to-back space is limited but the homeowner still wants an integrated smart bidet toilet.

Its 590mm body combines the toilet and bidet functions into one fixture. This avoids adding a separate freestanding bidet, and it avoids the uncertain fit that can occur when installing an aftermarket electronic seat on a compact toilet bowl.

The current K80 specifications include:

• Rear and front washing modes
• Adjustable water pressure and temperature
• Instant warm-water cleansing
• Heated U-shaped seat
• Warm-air drying
• Automatic flushing
• Hidden water tank
• Dual-waterway design separating fresh-water cleansing from the designated flushing-water supply
• Integrated booster pump
• Remote control

The built-in tank and booster system are designed to support flushing when household water pressure is low or inconsistent. This is particularly relevant in apartments and renovation projects where direct-pressure flushing may be unreliable. The dual-waterway design keeps the bidet cleansing supply separate from the flushing circuit, allowing fresh water for cleansing and the building's designated flushing water—including seawater where available—for toilet flushing.

Check P-Trap or S-Trap Compatibility Before Ordering

A toilet’s projection is only useful if its outlet matches the bathroom plumbing.

A P-trap sends waste through the wall. An S-trap sends waste through the floor. These configurations are not interchangeable without plumbing changes or the correct product variant.

The K80 currently offers:

• P-trap wall outlet: 180mm rough-in height
• S-trap floor outlet options: 200mm, 250mm, 300mm, 350mm and 400mm

Measure the existing outlet before selecting a version. Do not choose based only on the current toilet’s external shape.

For a P-trap installation, measure from the finished floor to the centre of the wall outlet. For an S-trap installation, measure from the finished wall to the centre of the floor waste outlet.

Because connectors, tiles and wall finishes affect the final fit, ask your installer to confirm the measurement before ordering. For a broader preparation checklist, read our smart toilet plumbing requirements guide.

If your project is in Hong Kong, see our K80 P-trap smart toilet guide for Hong Kong small bathrooms for local wall-outlet and space-planning considerations.

How to Measure for a Small Projection Toilet

1. Measure the available depth

Measure from the finished rear wall into the room. Confirm that the toilet will not obstruct a door, shower screen, vanity drawer or walkway.

2. Record the outlet type

Identify whether waste exits through the wall or floor. If the pipe is concealed, ask a plumber to verify it.

3. Measure the rough-in

Use the centre of the waste outlet as the reference point. Record the measurement in millimetres and take a photograph for your supplier or installer.

4. Check the width

The K80 is 380mm wide. Allow space for cleaning and make sure nearby cabinetry does not restrict sitting or access to service points.

5. Confirm water and power access

Smart toilets need suitable water connections and an electrical supply. The K80 uses fresh water for bidet cleansing and a separate flushing-water circuit that can connect to the building's designated supply, including seawater where available. It is offered in voltage configurations for different markets, including 110V and 220V versions. Confirm the water connections, required voltage and local electrical requirements before ordering.

6. Plan for maintenance

Make sure valves, filters and connections remain accessible. Do not gain a few centimetres of space by creating an installation that cannot be serviced.

Does a Compact Toilet Sacrifice Comfort?

A short toilet body does not automatically mean an uncomfortably small seat.

The K80 uses a U-shaped heated seat designed to distribute weight across the sitting area. Nevertheless, comfort is personal. Compare the seat dimensions and shape with your existing toilet, especially if the users are tall, have reduced mobility or prefer an elongated bowl.

The best compact toilet is not necessarily the smallest model available. It is the shortest model that still fits the plumbing, users and daily routine.

K80 vs. a Conventional Toilet with a Bidet Seat

A conventional toilet plus an add-on bidet seat may be suitable when:

• The existing toilet already fits well
• Easy seat replacement is a priority
• The bathroom has enough projection
• A lower initial cost is more important than an integrated design

An integrated compact smart toilet such as the K80 may be more suitable when:

• Front clearance is limited
• The existing toilet is being replaced
• A clean one-piece appearance is preferred
• Warm washing, drying and automatic flushing are wanted
• An aftermarket seat may not fit a compact bowl

Measure the complete installed system in either case. A compact bowl with a large cistern or incompatible bidet seat may extend farther into the room than expected.

Is the K80 the Right Small Projection Toilet for You?

The K80 is a strong candidate when you need a toilet below 600mm deep and want integrated smart bidet functions. Its 590mm projection, multiple outlet configurations and built-in tank system address several common problems found in small bathrooms.

Before purchasing, confirm:

• 590 × 380 × 480mm fits the finished room
• The selected P-trap or S-trap option matches the waste outlet
• The rough-in measurement is correct
• The fresh-water cleansing inlet and designated flushing-water connection are confirmed
• Suitable electrical connections are available
• The seat shape meets the users’ comfort needs

Once those points are verified, the K80 can replace a bulky fixture with a more space-efficient toilet without reducing the bathroom to basic functionality.

View the K80 compact smart bidet toilet and available configurations.

Still comparing sizes? Browse BBbidet compact smart toilets for small bathrooms before choosing the model that best matches your space and outlet position.

Frequently Asked Questions

What is a small projection toilet?

It is a toilet designed to extend less distance from the wall into the bathroom. There is no universal official cutoff, so compare the exact depth of each model.

Is a 590mm toilet considered compact?

Yes. A 590mm projection is generally considered compact and falls below the 600mm level often used to describe very short-projection toilets.

Is the K80 a P-trap toilet?

The K80 offers a 180mm P-trap wall-outlet option as well as several S-trap floor-outlet configurations. Select the version matching the bathroom’s existing plumbing.

Will the K80 flush with low water pressure?

The K80 has a hidden water tank and integrated booster pump designed to provide tank-assisted flushing without relying solely on household water pressure.

Does the K80 require electricity?

Yes. Its heated seat, warm-water washing, dryer and automatic functions require power. Confirm the correct voltage and have the installation assessed according to local bathroom electrical rules.

Can the K80 use separate fresh-water and seawater flushing supplies?

Yes. The K80's dual-waterway design keeps bidet cleansing water separate from the toilet flushing circuit. Connect the cleansing inlet to fresh water; the flushing circuit can use the building's designated flushing-water supply, including seawater where available. Ask the installer to confirm both connections.