To say I am slightly obsessed with poo, lately would be accurate. As a permaculturist, I realize how valuable it is as a resource, part of a beautifully evolved system that worked for millions or billions of years, since animals crawled onto land. But I’m also fascinated by how I, and we, culturally consider it. Ancient cultures understood that poop is a valuable nutrient-rich resource, rather than a disease-ridden “waste” product, as our wanton disposable culture has entrained us to believe.
I’ve visited (and taught at) Paul Wheaton’s Permaculture paradise in Western Montana the past few years. He has a large-scale setup to capture human waste (outhouses), which he calls “willow feeders“. While there, I was able to harvest some 2-year aged humanure, witness firsthand how this “brown gold” became a rich soil amendment. We poured it at the foot of some willow trees.
I recently read Joe Jenkins’ great book on Humanure, with his closed-loop system of capturing waste, composting it, and returning it to the soil. From his book:
Joe’s setup is more suitable for the home or farm scale, while Wheaton’s larger 32-gallon trash can format for capturing waste is suitable for larger and/or public establishments serving dozens or hundreds of people.
Physiology of Squatting
Two-legged animals like we humans are naturally built to squat when pooping.
The greater the hip flexion achieved by squatting, the straighter the rectoanal canal will be, and accordingly, less strain will be required for defecation”.Dr. Ryuji Sakakibara
You can still see this preferred posture in most non-Westernized cultures, where a flush toilet (don’t get me started on using potable water for poo!) may look a little different, if it’s even more than a hole in the ground with a few footpads.
Squat stools seek to recreate the anatomically correct posture by retrofitting Western toilets to elevate the feet closer to the bum, increasing hip flexion, and lessening the angle between your torso and legs, which makes pooping much more pleasant. This, of course, assumes a certain degree of flexibility in your hips, which, sadly, is not the norm among Westerners.
These commercial stools usually come in a few sizes. Squatty Potty, the original innovator of modern squat stools, for example, makes a 7 inch (“beginner”) and 9 inch (“advanced”) model. This is the height of the stool as measured from the ground. This is important, and assumes a standard toilet height of 16 inches from the ground to the bottom of the toilet seat.
Compost toilets, like the one I built, are based on the height of a 5 gallon bucket or other receptacle, and may differ slightly from the standard height. Therefore, it is more useful to measure the distance from the bottom of the seat to the top of the stool, where your feet rest. To borrow terminology from barefoot & minimalist shoemakers, I will call this measurement stool drop (don’t get me started on the poop jokes! 💩)
The vertical distance (height) between the bottom of seat and top of foot platform determines degree of hip flexion. The greater the distance, the less hip flexion/greater hip extension, and “easier” for most Westerners or those who aren’t advanced yogis. The closer your feet and rear are to the same horizontal plane, the deeper the squat. If you are in a full anatomical squat, where your feet and bum are practically parallel, that is about a 3 inch stool drop.
Squatting Proficiency Chart
|Stool Drop (inches)
|Hip Flexion Angle (degrees)
|180° (pooping not recommended in this posture)
|Western Non-squatter (“Right Angler”)
|90° (not great)
|45-60° (should be transitional as you work toward a deeper squat)
|20° to 25°
I wanted to add a squatting feature to the Jenkins-inspired Loveable Loo basic compost toilet. Riffing off Jenkins’ design (which is built around a standard U.S. 5 gallon bucket), I decided to add some ergonomics to the baseline bucket-in-a-box toilet concept, incorporating a stool to encourage a squat position.
This prototype model has a 8.5″ stool drop, somewhere between beginner and moderate squatting skill level. (See chart above.)
Future iterations will be designed to adjust the drop height for different users and people of different heights.
What do you think? I’d love feedback on the design.
They’re about to start construction on an additional dwelling unit in my backyard. As soon as I know whether I will need to move my compost bin (the other critical component of a closed loop humanure system), I will start the home humanure flywheel process. I do not wish to have to move a partially poo-filled compost bin!