Aqua Gratis Greywater reuse
Build homes
that use less
mains water.
Aqua Gratis collects water from baths and showers, filters it and uses it again to flush toilets.
How it works
From the shower
to the next flush.
Follow the water through Aqua Gratis, from the moment it leaves the shower to the next time a cistern refills. See the whole system
Collect
Water leaving the bath or shower flows into the system. The first filter catches hair.
Filter
The water passes through a series of tanks. Particles settle out and finer filters trap smaller debris.
Store
The filtered water stays in the unit until a toilet cistern needs to refill.
Flush
Reused water feeds a dedicated cistern by gravity, or a pump supplies toilets on the floor above.
Technical overview
Where does
the unit fit?
Choose a unit with an integrated toilet, a standalone core or a configuration designed for the project.
Compare Aqua Gratis modelsShower heat recovery is optional across the range.
Project planning
What does your
team need to know?
01Housebuilders & developers
Start with the house types, plot numbers and water demand assumptions for the scheme. Cascade can discuss which layouts could accommodate reuse and what evidence you need for the next design review.
Discuss a development02Housing providers
Bring your questions about access for servicing, who maintains the system and what residents need to know. A discussion about a representative property is a useful starting point.
Plan a housing pilot03Architects & specifiers
Start with the bathroom layout and proposed pipe routes. Ask Cascade for current model drawings, service clearances and connection requirements before specifying a unit.
Open the Technical hub04Water-sector partners
Discuss a potential pilot, the building’s mix of shower and toilet use, and how mains water demand would be measured before and after installation.
Explore the Cambridgeshire pilotProjects Cambridgeshire
Putting water reuse
to the test.
In July 2026, the Water Efficiency Cambridgeshire Fund selected Cascade to run five commercial Aqua Gratis pilots. The project will examine mains water savings in business settings and train local plumbers.
Explore the pilot projectDiscuss a project
Could Aqua Gratis
fit your project?
Tell Carolyn where you’re building, the type of property and how far along the design is.