Treebog

It consists of a raised platform above a compost pile surrounded by densely planted willow trees or other nutrient-hungry vegetation.

It can be considered an example of permaculture design, as it functions as a system for converting urine and feces to biomass, without the need to handle excreta.

[5] In 2011, Abrahams claimed that the treebog had attracted the attention of NGOs and aid workers who hope to develop its potential for shanty towns or refugee camps - anywhere that water is scarce and the population pressure on resources is high.

The area beneath the seating platform is enclosed by two layers of chicken wire or plastic mesh, which act as an effective child-proof barrier and allows air to circulate through the compost heap.

Sawdust, straw, woodchip, ash or other high-carbon matter is used to cover the excrement and balance the high nitrogen content of the urine.

A Treebog could be built with a bench-type seat, as in this ArborLoo , only there is no hole in the ground and it is raised one meter above the ground. The excrement is surrounded by a barrier of mesh, straw, and trees, such as willows .
Plastic mesh would be preferable to avoid rust and the release of heavy metals. A mesh could potentially even be woven from strips cut from plastic bottles rescued from the garbage.
Coppice d willows or other species of trees help to contain the feces and create a place where they decompose quickly.