How does a Composting Toilet work in a Tiny House?

If you’re like most people, your only experience of a composting toilet is an overused, under-maintained, smelly public drop system compost toilet on a roadside stop or visit to a national park! However, there’s more than one kind of composting toilet and in fact there is a range of waterless composting toilet solutions for Tiny Houses that are compact for small bathrooms.

What you must know about composting toilets for Tiny Houses

• They are an easy to use waterless system
• They don’t smell when used correctly
• Yes, you can use toilet paper
• And emptying the bucket is a lot easier than you think

At Aussie Tiny Houses we believe in sustainable innovation. We work with our eco-friendly equipment suppliers to design and engineer new and improved products. 

The Research and Development team led by Thiago, ATH’s Operations Director, works alongside suppliers to improve or develop new technologies that enhance our Tiny Houses. Aussie Tiny Houses collaborated with Ecoflo, the largest compost toilet manufacturer in Australia and our grey water system and toilet supplier, to develop a composting toilet system specifically for Tiny Houses.

So what is a composting toilet exactly?

A composting toilet is waterless. It isn’t plumbed into the sewage system or septic tank and it doesn’t flush with water. A urine diverting composting system collects the solid and liquid waste in separate compartments. This allows the solid waste to break down and dry, away from the stronger smelling urine. Unlike a portable toilet which you might see in a caravan, composting toilets are fixed to the floor, look like regular toilets and don’t use chemicals. Some systems require wood chips or peat moss to help dry the solid wastes and all composting toilets need emptying manually. 

How does a composting toilet for a Tiny House work?

In a urine diverting system, urine collects in a separate compartment of the toilet. Below the bowl are either two buckets (one for solids and one for liquid waste) or a single bucket for solids, with urine piped out as black water to join the grey water system. If the model has a container for urine, it’ll need emptying every day or so because it tends to smell. The hard waste might only need emptying every 2 to 3 months, depending how dry it’s kept and how many people use the system.

In some composting toilet designs the back compartment has a bucket which is covered by an automatically opening and closing flap. Great at keeping odour and flies away! The bucket sits on a platform that rotates slightly when you sit so that waste is distributed evenly. 

Some composting toilets have a quiet exhaust fan which runs 24/7. It extracts air from the solid compartment to the outside which dries the waste and eliminates odour. The fan eliminates the need to add wood chips or peat moss after use.

What will it take to maintain a composting toilet in my Tiny House?

One way to approach maintenance of a composting toilet is every 2 to 3 months when it’s time to empty the solid waste bucket, clean the filter over the fan, rinse the buckets with water and wipe down the toilet with disinfectant. Once a week in her semi-off grid Teewah Tiny House Amy from @life_done_simple pours hot water down the urine bowl of their composting toilet to help remove any build up of minerals and keep the pipe draining freely. Sometimes, for an extra deep clean she uses bi-carb soda and vinegar. Just like a standard toilet, a once a week wipe down or whenever you clean the bathroom is good to do to maintain the toilet. 

Watch the Ecoflo Clivus Multrum Low Profile Composting Toilet Service and Maintenance Demonstration

Pros, Cons and Options

Although it does mean getting closer to your body waste than you might be used to and putting in time to maintain, a composting system really is an eco-friendly, cost effective choice. A composting toilet doesn’t require plumbing in or a septic system which can cost over $10,000 and make it difficult to find a parking spot! It saves water and provides organic compost. Urine is a great fertilizer for mature trees or can be diluted for plants. Diluting Urine with eight parts water to one part urine will ensure you have a great liquid fertilizer for your plants and smell will not be an issue. Solids are best added to the garden compost to finish composting. 

Most homes with a composting toilet have instructions on the door for visitors who might not know how to use it. Guys might need to sit down to pee in a urine diverting system. A final consideration in the cons is that the flap at the base of the bowl can trap toilet paper or solids, although it rarely happens, and it just means manually removing it.

Click to download Amy’s Visitor Tip sheet on how to use her composting toilet

Watch Amy’s video on how to change the bucket of solid waste every 2-3 weeks.

You’ll easily come to understand your composting toilet system and can troubleshoot when things go wrong without needing to call a plumber. We’re here all the way with after sales service and complete instructions on each toilet model. 

More Off-grid options for a Tiny House

All of our Tiny Houses can be upgraded with off-grid options. We design them to provide you with the choice for independent off-the grid living. 

Off-grid upgrades:

• Electricity (Solar Systems and Generators)
• Composting Toilets
• Water Storage Tanks, Gutters and Filtration Systems
• Grey Water Systems
• Grease Trap Systems

Have you got a question about composting toilets for a Tiny House? We’re here to help, Contact Us!