My partner and I built a Tiny House and we saved the best for last – the bathroom! We’ve decided to go with a composting toilet, and my research began with the simple DIY bucket unit and has now moved onto the more “high-tech” options available. Below I’ve listed three manufactured compost toilets specifically for tiny homes. Each of these units are self-contained, waterless, and include some form of ventilation and aeration.
I hope this list is helpful but keep in mind that there are many options out there. Choose the commode that works best for your tiny home!
1). Nature’s Head
PRICE: $925 / Made in USA
SIZE – 20″ toilet seat height X 22″ width needed for handle / vent use X 20 5/8″ depth required / 28 lbs
COMPOST CAPACITY – approx. 90 uses
VENTILATION – Vent mounted at the side rear of the unit / 12V fan
AERATION – Crank aeration
URINE – Diverts urine into small built-in holding take
INSTALLATION – Video here. Bonus video – Art’s Nature’s Head
PRICE – $1389 / Made in Sweden
SIZE – 17.3″ toilet seat height X 19.95″ width X 30″ depth required / 48 lbs
COMPOST CAPACITY – Family of four will need to empty container every 3-6 weeks.
VENTILATION – Vent mounted at the top rear of the unit / 12V fan
AERATION – When pressure is added to the seat, the chamber is rotated
URINE – Diverts to a separate waste tank (not included in unit)
INSTALLATION – Video (1/2 way down page) here.
3). Sun-Mar Excel-Ne
PRICE: $1645 / Made in North America
SIZE – 26.5″ toilet seat height X 22.5″ width X 46″ depth needed to empty / 50 – 95 lbs. *Sun-Mar also has a mobile version that is smaller, but requires more electricity.
COMPOST CAPACITY – Family of three will need to rotate chambers every three months. The unique aspect of this toilet is that it has three chambers, allowing compost to fully form in the third chamber.
VENTILATION – Vent mounted at the top rear of the unit / 12V fan optional
AERATION – Crank aeration
URINE- Liquids are evaporated within unit / no diverter. Requires a drain for excess liquid.
INSTALLATION – Video here. Bonus informational video here.
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What do you do with the waste after emptying your toilet? You can, of course, compost your waste – that’s the whole point! Although, the amount of time required before safely giving your waste back to mother nature depends on several factors, including your chosen unit. I would recommend reading The Humanure Handbook by Joseph Jenkins, which has a lot to say on the subject. In fact, I know exactly where you should store this book… right next to your current toilet.
My decision? Drum roll please…….. I ended up choosing the Nature’s Head compost toilet for our tiny house. The size is a perfect fit for our small bathroom, allowing us to build future storage space around the toilet.
Guillaume (my partner) & Salies (our dog) modeling our new compost toilet!
It is important to note that the liquid coming out of the Sun-mar overflow drain will be fecal contaminated. It absolutely cannot be drained into a pit or added to gray water. You can drain uncontaminated urine into a gray water system or pit. That is one of the reasons many people prefer urine diverting designs. Second, with a little creativity, you can plumb the Nature’s Head so the urine drains away into your gray water system, and you don’t have to empty the bottle.
Can a composting toilet in a Tiny House be changed out to a septic toilet? What would be the approximate cost to do this?
Switching from one compost toilet to another is usually pretty simple. Switching from a compost toilet to a flush toilet will require a lot of plumbing work which may cost around $1,000