Here's the Poop on Composting Toilets for Tiny Houses! 

All Tiny House builders have to make the "big decision", compost or flush?

Composting Toilets

Composting simply means the process of breaking down or decomposing organic matter. Human waste is about 90% water, which means that one of the primary functions of a composting toilet is evaporation. Electric models include a fan that is constantly moving air through the unit to accelerate the drying out. Bulking material and microbes are added to break down the remaining minerals and what you are left with is a clean, dry, non-offensive compost - the very same stuff you'd find at your local nursery that you feed your plants. 

The main factors to consider are their size and footprint, energy requirements, the clean out process, and whether you can eliminate the odor. I can say with certainty that dealing with a compost toilet is 100% less disgusting than dumping black water from a septic tank. Plus, it requires zero fresh water to operate.

Pros: They reduce contact with your waste. They don’t require any special plumbing. Since your composting toilet doesn’t use water to flush away your waste, it doesn’t need a water supply, and it doesn’t need a drain. That actually represents significant cost savings on your plumbing setup. They are environmentally awesome! Microorganisms break down your waste and turn it back into soil.

Cons: Can be more expensive, but they are well worth it!


EcoJohn Self-Contained Composting Toilets | Tiny Houses InsideSeparett Composting Toilets for Tiny Houses

Comparison of Tiny House Composting Toilets

These compost toilets are made for tiny houses. Each of these are self-contained, waterless, and include ventilation and aeration.

Composting Toilet Capacity
(Constant Use)
Why choose this one? Power Price
ECOJOHN BASIC-120 2 Adults  abc... Electric 120vAC $1475
ECOJOHN BASIC-12 2 Adults  abc... Electric 12vDC + Solar Kit Option $1475
SEPARETT VILLA-9200 Unlimited Adults  - Odor-Free! Electric 120vAC $1389
Unlimited Adults
 - Odor-Free! Electric 12vDC or 120vAC, + Solar Kit Option $1389
SEPARETT 7000 WEEKENDER 1 Adults  - Portable Non-Electric $889


Let's look at why you'd want to go with a composting toilet instead of the alternatives for your tiny house.

Low-Flush RV Toilets?

Pros: These will most look and operate like the toilets you're used to. Some tiny houses have these, choosing to operate as RVs do. Cons: like RVs, you must have a septic holding tank and find some place to dump it when it is full. 

Incinerating Toilets?

Pros: Incinerating toilets are waterless and don’t need as much attention as composting. Cons: they are very expensive, use too much energy to be powered by solar, and or small generators, and to top it off, they’ve been known to be smelly!