Toilets With Sinks On Top | Bathroom Mountain

FAQs

What is a toilet with a sink on top?

A toilet with a sink on top, often called a 2-in-1 toilet and sink combo, piggyback toilet, or washbasin WC, is a space-saving unit where a small hand-washing basin is mounted directly on top of the toilet's cistern.

How It Works

Hand Washing: You wash your hands using the small basin on top of the tank.
Reclaimed Water: Instead of going down a drain, that clean wash water flows directly into the cistern to fill it for the next flush.
Flushing: Once the cistern is full, it functions exactly like a standard toilet.

How does a toilet with a sink on top work?

A toilet with a sink on top works by rerouting clean water through the tap before it fills the toilet tank.

Step-by-Step Operation

You Flush: The toilet flushes normally, emptying the water stored inside the tank.
The Tap Turns On: As the tank starts refilling, clean water is automatically pumped out of the sink tap instead of filling the tank directly from the bottom.
You Wash: You wash your hands under the running tap water using soap.
The Water Filters Down: The soapy water drains out of the basin and directly into the toilet tank below.
The Tank Fills: The drained water fills the tank until it reaches the float valve, which automatically shuts off the tap.
Ready for Next Use: The greywater stays in the tank, ready to flush the toilet the next time it is used.

Are toilets with sinks on top water efficient?

Yes, toilets with sinks on top are exceptionally water efficient and can reduce your bathroom water usage by up to 26% to 50%. By reusing \(100\%\) of your hand-washing water to flush the toilet, they completely eliminate the need for fresh water during that next flush.

Are toilets with sinks on top suitable for small bathrooms?

Yes, toilets with sinks on top are highly suitable for small bathrooms. In fact, small bathrooms, cloakrooms, and en-suites are the exact spaces they are designed for. By stacking the basin directly onto the toilet tank, you completely eliminate the need for a separate hand-washing vanity, freeing up critical floor and wall space.

Do toilets with sinks on top require special plumbing?

No, toilets with sinks on top do not require any special external plumbing. They connect to the exact same water supply line and main soil (waste) pipe as a standard, traditional toilet.

Are toilets with integrated sinks hygienic?

Toilets with integrated sinks are generally hygienic. Because the sink uses the same fresh, clean water supply as a standard tap, handwashing is entirely sanitary. However, the shared space presents specific maintenance considerations and potential hygiene drawbacks depending on the exact model.

The Pros

Encourages handwashing: Placing the sink directly over the cistern makes it impossible to forget or skip washing your hands after using the toilet.
Reduces cross-contamination: You don't need to touch doorknobs or walk across the room with unwashed hands to reach a vanity sink.
Clean the bowl: Many of these units are designed to use the soapy, grey wastewater from your hands to refill the toilet tank, which can help keep the bowl clean.

The Cons

Proximity to contaminants: Having a handwashing basin directly adjacent to the toilet pan can lead to germ spray and cross-contamination when the toilet is flushed without the lid down.
Higher cleaning burden: Tight gaps and crevices where the sink meets the porcelain cistern require regular, meticulous cleaning to prevent grime buildup.
Limited water volume: If your unit relies on the sink water to fill the toilet, a quick hand wash may not produce enough water for a proper, heavy flush.

What styles of toilets with sinks on top are available?

Toilets with integrated sinks are available in three core styles, each catering to different spatial needs and design aesthetics. Choosing the right layout depends on your bathroom's plumbing flexibility and available floor space.

Close-Coupled 2-in-1 Combos
Back-to-Wall Furniture Units
L-Shaped & Straight Combination Units

Are toilets with sinks on top easy to clean?

Yes, toilets with sinks on top are generally easy to clean because they are compact, but they do require more frequent attention than standard setups. Their ease of cleaning depends heavily on the specific style you choose.