Lennart and Sonia live in a house which has a natural organic cleaning of their grey water (dishes, laundry and shower water) situated in Gammelgarn on the east of Gotland. The cleaning system is based on the photosynthesis where the water is cleaned with the help of the sun, air, movement and vegetation. The Living Wall, which is what they call this technique, has been in operation since 2006. Samples taken of the cleaned water after the first winter showed that it fulfilled even the quality requirements for drinking water.

The house also has a separation toilet where the urine is collected via sewage pipes in an underground container. Faeces are collected in plastic bags (biodegradable bags are on the way) which are composted on a concrete slab in the far corner of the garden. After around 6 months they will become earth. The urine is taken by a local farmer who uses it as fertiliser. The couple not only have a sustainable way of managing water and sewage but, as a bonus, can also harvest fresh vegetables, spices and flowers from the wall. "We see the urine and faeces as useful resources rather than waste products".