The invisible upgrade: How Expella engineered the award-winning odourless toilet

30 May 2026

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A breath of fresh air for bathroom design, Expella's award-winning odourless toilets eliminate unpleasant smells at the source. This patented design, now integrated into leading toilet brands, is setting a new benchmark for comfort, hygiene, and luxury in bathroom design solutions.

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Materials & Craft Building & Renovating Bathroom Expella

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Expella

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Casey Arden

On the scale of design breakthroughs, the most transformative innovations often solve problems we’ve learned to tolerate. The odourless toilet belongs firmly in this category; an idea so intuitive it feels inevitable in hindsight, yet one which took decades of persistence, engineering and regulatory navigation to realise.

At the centre of this innovative story is the Australian family business Expella and the intergenerational partnership between Geoff and Wes Quick. The journey began with the dissatisfaction with an odour extraction system Geoff encountered years ago. It worked, in a sense, but it was clumsy, reliant on external pipework, and prone to inconsistent performance. Like many solutions, it hinted at possibility while falling short of usability.

Geoff’s background in construction and property development grounded him in the realities of installation constraints. Soon, the idea of a better system took hold: one which could eliminate odour at the source without introducing complexity elsewhere. But it would take years and a second generation to bring this idea into fruition.

The ambition was deceptively simple: to create a fully integrated, self-contained system which removes odour directly into the sewer, eliminates the need for external ducting, and, importantly, removes the variability of installation error.

The engineered solution became a compact, integrated fan unit which draws air from the toilet bowl and channels it into the sewer line.

A patented mechanism prevents backflow, ensuring that what is extracted doesn’t return. There is no need for additional pipework threading through walls or ceilings, nor for multiple trades to coordinate installation.

Compliance for real world applications at scale

Creating the solution seemed to be only half the job. In Australia, where plumbing and building standards are among the most stringent in the world, innovation must also prove itself through compliance.

For Expella, this meant a four-year journey through the regulatory approval process. A process which tested the product and the resilience of its creators. Achieving certification was as much a milestone as the invention itself, signalling the system could meet the demands of real-world application at scale.

Performance, too, required verification beyond internal testing. Independent analysis conducted by the University of New South Wales confirmed what the engineering suggested: the system eliminates 99.7 percent of odours. Backed by computational fluid dynamics modelling, the findings positioned the technology beyond a marginal improvement; a near-total solution to a long-standing issue.

Recognition followed, including a Best in Class accolade at the Good Design Awards. The Milu Odourless Toilet, awarded the 2020 Good Design Award Best in Class in the Product Design Hardware and Building category, is a sign the industry is beginning to understand the significance of what has been achieved.

The Good Design Awards Jury noted, “a clever blend of design and technology innovation brought together to resolve an age-old problem,” adding, “it has the potential for significant commercial impact, particularly in fit-outs that use in-wall cisterns.”

But Expella’s next move is perhaps more telling than any award: rather than attempting to displace established bathroom brands, it chose to work within them.

Fairlight project design by Robinson Jolly and Straight Up Built.

Copacabana project by BTM Constructions and Kristin Rawson Interior Design.

An integrated upgrade for top brands

Through its work with Caroma, Expella has embedded its odourless technology directly into a product line already trusted by architects, builders and homeowners. As an authorised stockist of Caroma, Expella integrates the system before dispatch, resulting in the end product arriving ready to perform as intended within quality branded toilets. The innovation becomes part of the familiar, an integrated upgrade rather than a disruptive replacement.

A similar philosophy applies with Geberit. By pairing the odourless system with Geberit’s in-wall cisterns, Expella opens up design flexibility for Australian specifiers. The technology can now sit behind almost any pan or flush plate, allowing architects to prioritise form without compromising function. An expansion of possibility integrating seamlessly into existing design workflows.

This approach of embedding rather than overtaking may prove to be the tipping point. As one design principal reportedly told a room of peers, the question is no longer whether the technology works, but why it wouldn’t be specified as standard. When an innovation reaches this stage, it has crossed from novelty into expectation.

This shift towards invisible, user-centric upgrades demonstrates how true luxury design lies not only in lavish fixtures and finishes, but also in clever solutions. Now with leading brands housing this patented system, the odourless toilet has, perhaps most importantly, demonstrated that even in spaces as familiar as the bathroom, there is still room for reinvention.

Learn more about Expella’s Odourless toilets on ArchiPro.