Treebogs compost human waste in a simple, solar-powered way. They require no water, have no plumbing and are not connected to sewers. Treebogs do not add to water pollutions and all waste is 'treated' on site. They were originally developed for use on campsites and at outdoor events such as fairs and festivals, to replace pit latrines and chemical toilets. Now there are even designs for household use.

Treebogs are basically toilets built over compost heaps which are surrounded by a tight double row of biomass willow cuttings. The willows are allowed to grow and can be woven into living walls.

The treebog idea has grown out of the fact that willow can be a very greedy feeder that will thrive on faeces and urine in quite large quantities which the willow converts into leaves and wood.

Between the willow wall is placed straw to absorb excess moisture. The straw provides a huge surface area with air passages throughout which allows micro organisms to get on with the job of breaking down urine into useful nutrients for the willow thus preventing a nasty pong.

As a living sculpture, the long willow shoots can be woven into many forms so that the treebog privvy can be housed in bowers or gazebos and decorated with a wide range of willow stem colours that also supplies withies for basket making and other uses.

The tree bog is a great example of permaculture, turning a 'problem' output (human faeces and urine) into a useful input (biomass for fuel, withies for weaving etc).