What are composting toilets?

If you’re new to the world of composting toilets you probably have a tonne of questions. How do composting toilets work? Can I install one myself? How quickly do they fill up? Do they smell? 

We cover all these questions and more in this article outlining what composting toilets are, how they work and answer (hopefully) all your questions.

So, what exactly are composting toilets?

Everyone living in Australia will be familiar with flushing toilets that use water to flush away human waste, which then travels through a series of pipes where it is eventually processed in a waste-water treatment plant. 

Whilst this is a convenient way to dispose of human waste, it does waste millions of litres of perfectly good drinking water every day. Considering we live on the driest continent on earth, it makes sense that we should be preserving this precious commodity. 

Composting toilets are a way of self managing human waste to turn it into a usable, humus-like top-soil that can be used on fruit trees, gardens and lawns. It uses aerobic composting and anaerobic composting to break down human waste into something usable. 


Are there different types of composting toilets?

Yes, there are different types of composting toilets and the type of home you live in, the space you have in your bathroom, the number of people you have living in the home fulltime and the floorspace you have under your home will all impact on the type of composting toilet you may choose. Roughly speaking composting toilets can be broken down into three different types:-

Self contained composting toilets

A self contained composting toilet has all the components needed to compost human waste integrated into the one unit. They have a chamber that sits inside the pedestal and typically have a mixing mechanism that helps to aerate the compost pile. 

Self contained composting toilets are great for homes on concrete slabs, homes that don’t have any space under the house or sheds, caravans and holiday homes. 

Split system composting toilets

A split system composting toilet separates the chamber and the pedestal by a chute. The chamber where the waste goes is usually installed under the house or in a basement then a chute is installed from the chamber, through the floor and connected to the pedestal that sits in the bathroom. 

Split systems are great for larger families as you’re able to install a larger chamber to suit your needs. 

Microflush composting toilets

A microflush toilet is the same concept as a composting toilet however, it uses a small amount of water to flush away waste to the chamber. The main reason people install a microflush toilet is positioning. Having that small amount of water flush away waste matter means the chamber doesn’t have to be directly under the pedestal. 

What are the components of a composting toilet?

There are several components to a composting toilet system and these are listed below. Diagram 1

The Pedestal

The pedestal is the part that you actually sit on. The seat, the throne, the John. Whatever you want to call it – this is the part your bum goes on. 

The Chute

This is more for a split system and microflush toilets – the chute looks exactly how it sounds. It’s a round piece of plastic piping that connects your pedestal to your composting chamber. 

The Chamber

This is where the magic happens. When you finish your business, your waste makes its way into the chamber where it is mixed up with a combination of raw materials (we recommend using mini help bulking agent) and microbes to break down waste material into a top-soil like product over the timeframe of a few months. 

The Exhaust Fan

This is an incredibly important part of any composting toilet. The exhaust fan runs constantly to evaporate liquids away from your compost pile. A pile that’s too wet will tend to get smelly and can even kill off all the good bacteria, actinobacteria, fungi and moulds that break down all the waste into a usable product. 

The Vent

This is connected to the exhaust fan and is essentially the escape hatch for moisture in your composting pile. Air travels around the composting pile, then is pushed by the exhaust fan through the tube and into the surrounding environment. 

Are composting toilets legal?

Yes, composting toilets are legal in Australia but local and state legislation does change depending on where you live. Hence, it’s a good idea to check with the appropriate councils before installing a composting toilet in your tiny home.  

For more information and links to the relevant state legislation websites, look at our article Are composting toilets legal in Australia?.

Do composting toilets smell

Honestly, the answer is yes, but ONLY if there is something wrong. A smelly composting toilet is a sign something isn’t working – like the exhaust fan, you’ve killed your pile or something isn’t working the way it should.

A properly functioning composting toilet does not smell. 

Can composting toilets freeze?

Yes, although, pretty much anything will freeze if it gets cold enough. In Australia it’s really only people who live in parts of Tasmania and at high altitudes that need to worry about their composting toilet pile freezing. This can easily be alleviated by insulating your chamber or by purchasing a heating pad.

How much do composting toilets cost?

This will depend on several factors. How big the system is you purchase, how many additional chambers you purchase, the type of composting toilet you buy, etc. 

Our composting toilets range in price from just under $1,000 right up to the larger commercial units which can cost upwards of $8,000 (keep in mind this type of unit will handle up to 28 people full time).

If you have any additional questions about composting toilets, how they work, what they do or how much they cost, please feel free to contact our customer service centre on 1300 138 182 where one of our friendly agents will be more than happy to answer any questions you might have.