Timber Frame Compost Toilet and the Joy of Poo


Home » Timber Frame Compost Toilet and the Joy of Poo

We went to Grand Designs Live at the weekend and built a simple timber frame structure to house a compost toilet.

Carwyn Jones used joinery techniques such as dove-tailing, birds’ mouth joints, lap joints and Walter Seagal methods to build this simple, attractive frame. Raised about one and a half feet off the ground this structure would sit over two alternating compost chambers. The drop from the toilet is usually about four to six feet, with the waste collecting underneath in the chambers.

Visitors to the toilet leave a sprinkling of sawdust after each visit to ensure an aerated and dry compost. Once one chamber is full (usually after about 12 months), the toilet itself is moved to sit above the second chamber whilst the first chamber is closed to rest for twelve months. After these twelve months a nutrient rich and safe to handle compost is ready to put on your garden.

For more detailed technical information on compost toilets you can read our tip sheet here.

One of the most important factors in composting human waste is that it is an aerobic process. Unlike anaerobic processes, it is relatively smell-free, meaning that compost toilets, with the smell of sawdust and the outdoors, are actually pretty pleasant places.

‘I was really thankful for the compost toilets at festivals I went to in the summer and gladly paid the three quid for the privilege’ says local compost toilet user

Anaerobic processes in comparison release gases such as methane which have a notoriously stinky quality. Of course methane is also flammable meaning that through large-scale anaerobic composting of organic waste, we can produce fuel – commonly know as the process of Anaerobic Digestion.

For more information on anaerobic digestion and biogas you can read our information leaflet here.

This structure took three days to build, and used sustainable materials available at standard builders’ merchants. The typical cost of materials for a build like this is between £600-£800.

For more tips and advice on timber frame building, you can visit our info pages. Or alternatively treat yourself to a CAT course in sustainable building.

Illustrations by youtookthatwell.org