My partner and I are about 90% finished with our Tumbleweed Cypress 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
2). Separett - Villa 9210
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.
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!
Jenna Spesard is currently building a Tumbleweed Cypress with her partner, Guillaume, who is a professional photographer and Tumbleweed Workshop Host. After the build is complete, they plan to travel around North America in their tiny house blogging and photographing their adventure. More on their tiny house and giant journey here.
Confession: I'm kind of a simpleton when it comes to plumbing. Only in
recent years has it occurred to me to ask questions like, where does toilet
water go when I flush? And how is it suddenly replaced with clean water? And
sinks, and washing machines, and showers for that matter- what happens to all
my own waste water?
Is it magic?
Since that first realization of my ignorance regarding all things waste water, I've tried my best to learn a little more about plumbing. At times, it can be hard to remember how wasteful flush toilets
and long showers are.
Enter off-grid water recycling systems! Designing a Tumbleweed that doesn't require regular hook-ups is a great opportunity
to get to know your personal water usage. Here's a bit about how you can use greywater to minimize waste and take advantage of a great resource.
What is greywater?
Greywater refers to waste water that is relatively harmless
and can thus be reused for a variety of purposes. It gets the name "grey" for being somewhere between fresh water and sewage water.
Usually, the term encompasses
dishwater, laundry water and shower water. However, it is important that you
don't put ANYTHING remotely toxic in your sink, shower or laundry machine if
you're planning on reusing the water. It's pretty easy to avoid-just make sure
you're using biodegradable soaps, laundry detergents, etc.
I got some great biodegradable soaps for Christmas, and am excited to eventually
set up my own grey water irrigation system!
How is it reused?
Greywater is typically used for irrigation- most people
direct their grey water into gardens or mulch pits. Grey water can also be
recycled inside. Water from showers and dishes can be used in toilets, house
plants, and greenhouses.
Greywater reuse in a garden (Source)
You can get pretty creative- there's no one way to use greywater!
Remember, of course that greywater is never safe to drink. Filtration processes can render it safe to use for toilet water and washing water.
What's the difference
between greywater and blackwater?
Blackwater contains human waste, and cannot safely be used- generally, this refers to the water flushed in toilets. It contains pathogens that must decompose before they can be safely released into the environment. One way to avoid dealing with blackwater? Composting toilets!
Do you have a unique way of reusing greywater? Tell us about it!
This spring, Hampshire College Professor Gabriel Arboleda taught an unusual class: Reinventing the Toilet (course description). Addressing the fact that a single flush toilet can contaminate thousands of gallons in just one year of operation, he and his students will attempt to build alternative workable toilet models.
An important class? I think so. Many Tiny House folks would agree, having found that the mobile lifestyle necessitates flexibility when it comes to things like electricity and plumbing. Of course, there's an easy solution already at play, and it's something we don't think twice about doing with cows: composting.
I recently tried my first official composting toilet, and loved it. Our friends Pepper and Dylan built this awesome composting outhouse on their property in Healdsburg, CA, and were kind enough to let me, ahem, try it out.
Who knew an outhouse could be so beautiful?
In addition to the requisite crescent cut out, the outhouse has a light, a nice big bucket of a cedar chips, and a magazine rack!
A pleasure to use
Plenty of open-minded people like Pepper and Dylan are pushing the envelope with practical, conscientious ways to dispose of waste: while we wait for Arboleda and his crew to envision the next big alternative, we can manage pretty comfortably. While making a separate outhouse is a viable option, the bucket and cedar chips method can easily be applied in any tiny house.
In addition to the composting toilet, there's the incinerating toilet. Incinerating toilets are a bit more high-tech than a bucket and some cedar chips (though there are plenty of more advanced composting toilets available). Essentially, they incinerate your waste, converting it to a clean, non-polluting ash. An incinerating toilet can be powered a regular outlet, by gas, propane, or of course, solar panels. However, it uses more electricity than a composting toilet, and doesn't provide rich and useful fertilizer!
No matter your preferred commode, there's a reason colleges like Hampshire are highlighting the urgency of reinventing something most of us take for granted. We are far too distanced the effects from our own, for lack of a better word, crap. With the help of sophisticated indoor plumbing, most people never had to accept that what comes out of their body actually goes somewhere.
We want to live responsibly but we also want to live in a sanitary and safe. When choosing how to outfit our houses, we can think outside the porcelain box and attempt to do both.