Any toilet system will work for microhousing connected to traditional sewer/water hookups. When these are not available (such as in a tiny house/RV on wheels), there are three main toilet options: composting, incinerating, and the bucket. The chart below highlights notable sanitation options for micro living, which includes pricing and the pros and cons of twelve different toilet options.
Within the category of composting toilets, there are three different types: urine diverting, self-contained, and centralized. Composting toilets use waterless toilets with a composting tank to break down human waste into a fertilizer.
Urine Diverting Composting Toilets
Urine diverting dry toilets separates the liquid and solid waste at the source. Separating the solids and liquids drastically reduces odors created by the waste. The Separett Villa 9000 (extensively tested at the Micro Showcase), Nature’s Head composting toilet, and the C-Head composting toilet are examples of urine diverting toilets. See sanitation chart for further info and comparison.
Self-Contained Composting Toilets
Self-contained composting toilets attach the composter directly to the toilet seat and the composting process takes place in the bathroom. Because the toilet and the composting system are self-contained, the toilets are easier to install. The composting tank is smaller which means they will need to be emptied more often than centralized composting toilets. Sun-Mar Excel and Biolet BTS 33 Waterless toilets are examples of self-contained composting toilets. See sanitation chart for further info and comparison.
Centralized Composting Toilets
Centralized composting toilets allow the composting process to be done outside of the bathroom. A dry toilet is located in the bathroom with a composting tank located a level directly below the toilet. These toilets are easier to maintain because the tanks are generally larger and have to be emptied less often than other composting toilet options. Sun-Mar Centrex 2000 A/F non-electric and electric, and Envirolet waterless remote composting toilet are examples of centralized composting toilets. See sanitation chart for further info and comparison.
Incinerating toilets use electric heat to reduce human waste into a small amount of clean ash. These toilets are considered more sterile than traditional commodes. The Incinolet is an example of an incinerating toilet (extensively tested at Micro Showcase). See sanitation chart for further info and comparison.
A simple bucket can be used as a toilet. After each use, sawdust is added on top of the waste to reduce the odor. If appropriately managed, waste can be composted or disposed of. The Luggable Loo and the Lovable Loo are examples of buckets that have been transformed into toilets. The Laveo by Dry Flush is more complex than a simple bucket, but disposes of waste in a similar way. See sanitation chart for further info and comparison.
For foundation built microhousing, please consult local building codes on what options are permitted. If you have experience with any of these toilet options and have suggestions to add to the sanitation chart, please let us know in the comments.