Vacuum plumbing enabled an underground hotel conversion in London’s West End

The challenge: building a hotel where gravity won’t work

When Zedwell Hotels discovered a disused underground car park in London’s West End, they saw an opportunity to create something unique: a tranquil retreat beneath the city’s bustle. The brand’s philosophy centers on sleep quality, relaxation, and well-being, so what better way to deliver a peaceful atmosphere than by going underground?

But there was one critical obstacle: all 207 planned bedrooms would sit entirely below the public sewer level. Traditional gravity drainage simply wouldn’t work. Without a viable plumbing solution, the entire project would have to be abandoned.

The solution: vacuum technology for below-grade development

Evac’s vacuum sewage system made the impossible possible. Where gravity drainage would have required extensive and costly pumping infrastructure, or might have rendered the project unfeasible altogether, vacuum technology provided an elegant alternative.

The system design was straightforward yet effective:

• Each guest room was equipped with an Evac Optima 5 wall-mounted vacuum toilet and an Evac interface unit
• Wastewater is drawn through small-bore vacuum pipes routed within ceiling voids
• All sewage flows to central Evac Type 30 HQE 300 vacuum collection units
• From there, the waste is pumped up to the communal sewer at street level

Because vacuum systems don’t rely on gravity, the pipes can run horizontally and even upward, allowing complete flexibility in bathroom placement throughout the underground structure. The small-bore piping (significantly narrower than conventional drainage) meant minimal impact on the existing car park structure and ceiling space.

Environmental impact: water savings and circular economy

Beyond solving the drainage challenge, the vacuum system delivers substantial environmental benefits that align with Zedwell’s sustainability commitments.

Water conservation at scale

The Evac Optima 5 vacuum toilets installed throughout the hotel are expected to save over 2.5 million litres of water annually compared to conventional toilets. This dramatic reduction directly supports The London Plan’s target of reducing water consumption to just 105 litres per person per day–a critical goal for a city facing increasing water stress.

Supporting circular economy principles

By enabling the conversion of an existing underground structure rather than requiring new construction, the project exemplifies circular economy principles. The European Union estimates that retrofitting buildings instead of constructing new ones could prevent 103 million tonnes of greenhouse gas emissions between 2022 and 2050 in the EU region alone.

Reusing the disused car park kept materials in circulation, avoided demolition waste, and eliminated the carbon emissions associated with new construction. Vacuum plumbing technology was essential to making this adaptive reuse possible.

Project outcomes: a sustainable underground retreat

Completed in 2023 in partnership with EVDS, Evac’s UK channel partner, the Zedwell project demonstrates how vacuum technology enables development in locations where conventional plumbing creates insurmountable barriers.

Key Results:

• 207 guest rooms successfully delivered below sewer level
• 2.5 million litres of water saved annually
• Existing structure preserved and repurposed
• Zero compromise on guest experience or hotel operations
• Sustainable solution aligned with London’s environmental targets