There are many choices to be made when designing your tiny house. Whether you want to be completely off-grid, what type of bed do you want to have, if you have a loft is it stairs or a ladder? How much storage space do you really want or need, what kind of materials do you want to use in your house. How big will the house be? But one of the decisions that you might make will have key day to day impacts on your life, and that is what kind of toilet will you have?
If you want flexibility in moving and where you can place your tiny house then choosing a composting toilet (as opposed to one that need to be attached to mains sewer or have a septic) may be something you would consider.
For many people, they may have come across a composting toilet only in national parks. Often, they are large constructions, are maintained by the staff there and are a place where you are always careful not to let a mobile phone, wallet, set of car keys or other critical possessions fall! Tiny House composting toilets are of course much smaller in scale and can range from a cheap and cheerful homemade ‘bucket’ system to more expensive and commercially manufactured ‘separating’ systems.
This blog will reference the Nature’s Head Composting Toilet, which is used in Chris’ Mayflower tiny house and can be supplied by Tiny Footprint.
Points to consider when deciding if a composting toilet is for you are..
- Are you comfortable emptying a composting toilet (both solids and liquids) yourself, on a regular basis?
- Do you have access to a compost heap that will not be needed for your vegetable garden?
- Do you have a place you can empty a liquids container every 1-3 days? Either on the garden or down a current septic or toilet system?
- Who else will use the toilet?
Here are some tips that I have come across during use of specifically the Nature’s Head toilet. Overall in answer to the question ‘Are you glad you chose a composting toilet, the answer is a resounding ‘Yes’. The main difference to a ‘normal’ toilet is that a bit more thought and planning goes into use but it is worth the flexibility and reduced water usage.
It is always good to do some research and reading. One of the best ‘reads’ I have found on the subject matter is the ‘Humanure Handbook’ by Joseph Jenkins. This is available on Amazon or you can download the pdf version for free on his website: www.humanurehandbook.com/ This has a lot of science in it but is a very well written and funny book to read.
When designing your toilet area, allow some ‘wiggle room’ around your toilet to move it when detaching the vent to take it out, but especially for lifting the lid to extract the liquid bottle without having to unbolt the base. Consider using the toilet for a while BEFORE you attach to the floor with the brackets. We have not found it a requirement for safe standard use to attached it to the floor as the unit itself is quite heavy. Some people may want to bolt it to the floor and then release when emptying solids for added peace of mind, especially if children are using it.
- Think about how you will transport your toilet to the compost heap – it can get quite heavy. A small cart is ideal to take it from the door of your house across any trip hazards to the compost heap! I love my ‘Sherlock’ trolley from Bunnings and it is the perfect size.
- Be sure to keep the screw top for the liquids that comes with your toilet. You do not need this during ‘standard operations’ but will want to use it when emptying the liquids bottle. If you are going to carry a full liquid bottle through your tiny house, you will want to have this added insurance.
- Adding a small cup of white vinegar when you have an empty liquids bottle is a good way to reduce any smells. When you have replaced the empty liquids bottle in the base, you can pour vinegar straight into the toilet and perhaps flush down with a small amount of water if you do not like the smell of vinegar.
- Practice tipping out the liquids bucket with water first and work out how to handle it. One edge is straight and one curved so the bottle can slip while emptying unless you are used to it. This is not ideal. You will need to wash your jeans. Seriously, just try it with water once.
- The toilet is shipped with your first coir brick to use as the ‘starter’ in the toilet which then the solids mix with. This has microbes that start the breakdown process.
Using your toilet:
- You may want to ‘flush’ with a tiny bit of water if any residual liquid is left after use. Having a small cup left by the sink is a good way to just rinse things down and not to leave stains or liquid that can evaporate and smell. It may fill your liquids bottle up a little bit quicker but is well worth it.
- Always keep the seat down. If you don’t, you will find this is an easy way for flies to find the contents. And they will do, very quickly.
- If you have a lot of visitors who are not familiar with using composting toilets, keep some laminated instructions on the wall by the toilet, leave the instruction booklet in the bathroom for reading or just do a briefing when visitors first arrive!
- If you will leave your house for any time and do not want to leave the mains electric connected or a solar system running, be sure to have a way of keep the toilet vent fan running (through solar vent or other means). It needs to run at all times to help the composting to start and to keep smells out of your house. The venting is the reason you have no smell from your solids area of the toilet.
- Make sure any cleaning products you use do not kill your friendly microbes. It comes with a spray that is microbe friendly.
- Keep a spare coir block (or other ‘starter’ that you use) to hand to help if you have a situation where there is too much liquid in the solids bucket. This will happen if you let the liquids bottle become too full, it will overflow back into the solids area.
- Experiment with how much toilet paper goes into the composting section. Don’t be afraid to have a toilet paper bin that takes wet but un-soiled paper and which you just throw into the compost bin as well. This means you won’t fill you toilet up as quickly with paper.
Use recycled toilet paper, it definitely seems to break down more easily.
Emptying your toilet and managing your compost pile:
- If you are not going to be happy emptying the liquid bottle out late at night, or if you find you can’t plan around emptying to prevent ‘full bottle’ issues at 3am then purchase and keep a spare liquid bottle to hand.
- Some trees, including lemons and limes, love a diluted version of the liquids. Be sure not to pour directly onto the trunk and to dilute well so you don’t burn the roots.
- You can empty the liquid onto the compost pile.
- Keep shredded paper to layer over each layer of humanure or vegetables deposits. This is key to keeping the insects away as much as possible and to keep it from smelling. Being covered supports the thermophilic composting (see Humanure Handbook for details).
- And of course, be prepared to learn as you go. The list above will be missing something you encounter but nothing has been as bad as we expected it could be!