Many tiny house owners choose to install commercially manufactured composting toilets. These toilets collect and compost the deposits right inside the lower tank. They don’t typically use any water and instead dry the waste using a small heater and fan. Air is drawn through the waste and out of the unit at the top through a vent pipe. From time to time the compost is removed by the homeowner and used on ornamental plants in the yard.
These are different from Lovable Loos, which are simply a box with a bucket and toilet seat. Lovable Loos, RV toilets, and normal flush toilets are smaller by comparison. So use this drawing if you are designing a bathroom that can accommodate one of these. This drawing is modeled loosely after a Sun-Mar toilet design.
Having lived 7 or 8 years with a Sun Mar NE composting toilet, we switched to a Separett – much easier to deal with. It’s a urine diverting toilet and I just swap out the bucket when needed – composting is done outside – we have a strawbale compost “bin” – the waste is in a biodegradable bag and we cover it with a few shovels of dirt.