A composting toilet is a fantastic solution for any shepherd’s hut, cabin, boat, or indeed any type of space that isn’t connected to permanent infrastructure. Despite the assumptions you may have, a composting toilet is practical, hygienic and a great solution for your small, movable space – and no they don’t smell!
Let’s take a look at what a composting toilet is, how it works and 12 main benefits as to why a compositing toilet is ideal for your small space. You can also find the best composting toilet for your hut, cabin or small area.
Have you ever really considered the importance of a toilet in your home? In conventional bricks and mortar homes, the toilet is often taken for granted and already plumbed in ready to go. In a not so typical tiny home or space, such as a shepherd’s hut, log cabin or narrowboat, the toilet situation needs some serious thought.
One of the main differences between traditional and non-traditional homes is the flexibility. Traditional homes are connected into the local infrastructure – gas, electric, water, sewerage – meaning they’re not moving anywhere any time soon. The off-grid nature of unconventional homes is proving more and more popular with wanting homeowners thanks to the freedom they bring.
A compostable toilet is a great choice for shepherd’s huts as they don’t need connecting to a plumbing system, or even a septic tank. And no, they are not the same as an outhouse or portable toilet you get at festivals. Superb engineering means you can grab yourself an easy to use unit that decomposes waste efficiently and odourlessly.
What is a composting toilet?
A composting toilet is a toilet that breaks down human waste by using the natural processes of decomposition and evaporation. This recycling biological process is done by microorganisms under controlled aerobic conditions.
The eco-friendly living nature of a composting toilet makes them the ideal choice for a shepherd’s hut or tiny home owner who tend to be environmentally-minded by their nature.
Although the term ‘composting toilet’ can be quite loose (pardon the pun), most are a type of dry toilet that doesn’t use water for flushing. Self-contained composting toilets do need a certain amount of moisture in the composting chamber for the process to work. Solid waste entering the toilet is around 75% water, which then gets evaporated and removed through the vent system.
For residential use, there are two main types of composting toilet:
- Self-contained – this is an all-in-one system with all the composting action taking place underneath the unit you sit on. These are usually the perfect solution for your tiny home.
- Central/remote – the waste is directed to a remote composting location usually located in the nearby vicinity. This is more like your conventional toilet, but it’s a bigger operation to install than the self-contained unit.
During this article I’ll be mainly referring to self-contained units ideal for tiny homes.
How does a composting toilet work in a hut or cabin?
A composting toilet works in very much the same way as a garden composter does.
The main difference is that the specially engineered toilet quickens up the process by creating the ideal environmental conditions for waste decomposition. The information you’ll find below is all based on the important premise – solids and liquids (i.e. poo and wee) must be kept separate.
In the most basic terms a composting toilet needs two things: a place to sit down and a collecting/composting unit.
A model you buy is also likely to have a few other elements, such as a ventilation system, urine collection unit and access door for the dry leftover organic material, known as humus.
Within the composting unit itself, the right conditions need to be created and material added in order for it to work efficiently and productively. Namely, there are five main necessities:
- Deposited solid waste material
- A carbon rich material is needed to line the composting chamber e.g. dried moss, sawdust, coconut fibre, straw, peat. This has a three-fold job: to create air pockets in the waste material to promote an aerobic environment, and to help balance out the carbon-to-nitrogen ratio and reduce odours.
- Oxygen rich environment – aerobic bacteria require oxygen
- Correct moisture content in the chamber – the material needs to be moist but not wet
- Warm temperature (over 18oC is optimal) – for the aerobic bacteria
What happens in the composting chamber?
Once the waste is deposited, it will land in the composting chamber. All the processes which then happen in this chamber need to be operating in an aerobic environment. This is essential.
An aerobic environment, one that’s rich in oxygen, enables the aerobic bacteria to work their magic. The balance of oxygen, moisture content and the right temperature allow the bacteria to work optimally in breaking down waste into water, carbon dioxide and the remaining organic matter.
If decomposed correctly, the bacteria will have destroyed most pathogens or potential viruses, meaning the remaining material is safe to use soil fertiliser. You may have to move leftover waste to another composting step before it’s fully safe to use, but this will depend on the type of composting toilet. It’s thought one person may produce approximately 36 kilograms of dry humus per year.
Does a composting toilet smell?
A composting toilet will not smell if it is looked after properly. This means keeping oxygen and moisture at the correct levels to make sure it is an aerobic environment inside the chamber.
If the oxygen and moisture conditions aren’t ideal for aerobic bacteria, then anaerobic bacteria will thrive.
This type of bacteria operates without oxygen, which not only means it takes the waste longer to decompose, but it also produces a bad smell because of the byproducts of anaerobic respiration, such as ammonia, methane and hydrogen sulphide. Not what you want.
To reiterate, when maintained properly a composting toilets will not smell. Aerobic decomposition that takes place in the chamber produces carbon dioxide and water vapour, which are both odourless. A ventilation system attached to the chamber will keep fresh air and oxygen flooding in, whilst letting the venting gases be released outside. And just in the case, the chamber is also completely sealed off to the seated part of toilet, aside from the fleeting moment of a deposit.
12 benefits of a composting toilet vs flushing toilet
- They are self-contained and off-grid
- They are a sustainable and environmentally friendly alternative
- Doesn’t require a connection to a septic tank or sewer system
- Use very little to no water at all. A composting toilet may save ~25,000 liters of water a year per person!
- Doesn’t require an electricity connection or energy expenditure (unless you have a motorised ventilation system). It also saves a lot of energy used by waste treatment plants that have to process household waste.
- They take up little space and are ideal for a tiny home
- Ideal for a moveable environment e.g. boat, RV or caravan
- They provide a cheaper option to a plumped in, flushing toilet
- Composting toilets do not smell
- No added chemicals during decomposition, just pure natural biology!
- Can produce compost to use in soils and on gardens
- Very simple to install, doesn’t require an expert
Where can I buy a composting toilet and how much do they cost?
Like most things, you can get all-singing, all-dancing versions of compostable toilets that cost £2000-£4000, simpler versions for £200-£500, or a model somewhere in between the two.
Eco-loos.com produce a range of waterless, composting toilets complete with their own wooden unit. Made in Wales these units come in at the higher end of the scale and range from just over £1500 to £2800.
Waterlesstoilets.co.uk have a good range of composting toilets from popular Separett toilets starting around £500 to the extremely impressive premium Kazuba toilet cabins
You even buy from a wide range of composting toilets on ebay.com.
If you do buy a composting toilet, make sure you buy some eco-friendly toilet paper to go with it too.
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Ben is the Creator and Editor of Tiny Eco Home Life. I write and publish information about more sustainable, environmentally friendly living in and around the home.
Alongside this website, I love spending time in the natural world, living a simple life and spending time with my young family (Murphy the dog!) I round up my thoughts and recent blogs on the Eco Life Newsletter.