Tiny House Composting Toilet – Top 10 Options For 2021

Everything you need to know about tiny house composting toilet will be revealed in this article. The tiny house movement has certainly taken the world by storm. Individuals are choosing to downsize their homes and instead live in very small homes or even caravans, vans, or buses. Not only is this an easy way to reduce debt, but it’s also environmentally friendly. People may not be aware that tiny houses can have a significant impact on your lifestyle choices too!

I’ve written previously about how living tiny requires you to rethink what you own and also think differently about the kind of things you buy. Concerning food, for example, buying in bulk can cut down on packaging waste significantly.

But one area where there isn’t so much scope for recycling is when it comes to toiletries – shampoo bottles claimed 52% of the entire packaging waste generated in Australia in 2013 (Source: Australian Packaging Council) and also when it comes to hygiene products like toilet paper, tampons, pads etc. These items are often highly wrapped or packaged, and they tend not to be compostable.

I recently found an article written by Joe Smith that included some interesting information about the need for toilets and how this impacts tiny house living. Here’s what he had to say…

“Today I want to share with you a challenge with the tiny house movement that I think we all ignore at our own peril, which is basically what happens when someone needs to go? Yes, of course, there’s the infamous bucket system but what do you do if you’re visiting friends? Or traveling? Or just need to go now?”

“What if you know that for whatever reason, your tiny house doesn’t have the easiest system to access? Maybe you’re elderly or handicapped. Or maybe it’s one of those things where you’ve grown so used to having a certain level of privacy even when in communal spaces. Adding this much exposure is out of the question.”

Before we dive into what Joe Smith suggests as a possible solution, I want to highlight an interview that TreeHugger Radio recently focused on composting toilets. As I listened to Cameron Smith talks about his book “The Humanure Handbook” it made perfect sense why living tiny people should consider using composting toilets. According To Cam, “Toilets are the biggest source of water contamination in the world, and when you’re talking about tiny houses, if you’re living off-grid, let’s say a hundred gallons a week for a family of four. If every one of those goes into a septic system that means you need 1,000 gallons a week to process all that waste. That’s an awful lot of water to be going down the drain.”

One method that Cam suggests people consider is to use composting toilets. In his book, he explains what they are and how to build them correctly. This will be our primary concern today. We want to give you all the reasons to choose composting toilets for tiny houses and give you some of our best recommendations.

A composting toilet is a type of toilet that uses water-flushed siphonic action to wash waste away. Composting toilets are becoming more common in modern installations, replacing older gravity-fed models that require a holding tank for waste storage.

Compositing toilets combine traditional flushing mechanisms with newer technologies, such as pressure-assisted siphons and pressurized water supply systems. This means that, unlike many older types of cisterns or tanks, they do not have to be refilled after each flush. The contents are flushed out by freshwater, meaning there is much less risk of bacterial growth over time.

Compositing toilets are much easier to clean than older types because they lack large under-floor voids, which can be difficult to access. In fact, they do not require special cleaning materials or machinery at all. Because of their relative novelty, compositing toilets tend to be more expensive than most other cisterns. But this is likely to come down as they become more widespread.

Compositing toilets are currently available in three different designs: the twin-pan system, the single-pan system, and composting toilets that use a high-pressure vacuum pump to dispose of contents into large storage tanks outside the house. The latter type requires no water supply at all and can be used in homes without mains sewage connections.

The Twin Pan Composting toilet system

The twin-pan system is fitted with two bowls, one above the other. The upper bowl (called a urine diversion squatting pan) contains a removable cassette; the lower bowl (the composting chamber) usually has an integral water reservoir and stirring mechanism at its base, which mixes incoming wastes with wood shavings or sawdust stored in a cartridge located behind the toilet seat. This macerating method provides both liquid and solid outputs that can be used as fertilizer or soil conditioner. It also controls odors effectively.

Most macerating toilets have a seal around their openings so they can be connected directly to either a septic tank or to mains drainage pipes for disposal public treatment systems. These traps are needed to prevent gases produced by the decomposing waste from entering the living space.

The cassette is most often removed with the contents frozen (a “frost-free” model), and taken to a solid waste treatment facility equipped with the proper tools, or hauled away by approved truck service. The remainder of the toilet unit can then be serviced in place; some manufacturers recommend that their units be inspected every six months for possible servicing. This may involve adding water, replacing parts, or both.

Some composting toilets have a macerating mechanism built into their structure to crush even liquid wastes without plumbing connections to mains drainage systems. These types do not need cassettes and can be fitted into bathrooms or in other rooms.

The single-pan composting toilet system

The single-pan composting toilet system is designed with an integral container that is placed on or under the toilet pan. The container must be emptied by hand into a mains-connected bin, which is serviced by an approved specialist contractor.

These composting toilet types require very little ongoing maintenance and service: only the addition of water and bulking material such as sawdust and dry leaves. It can also contain some polymer gelling agents to keep odors in check while allowing liquids to drain out easily.

The twin-pan composting toilet system comprises one section that contains solids (the urine-diverting insert) and another section that collects liquids (a removable tray). This is the most significant difference between these two types of composting toilets.

Composting toilets that use high pressure

Composting toilets that use high-pressure fans to circulate air can also be called ventilated toilets. It is a common misconception that some composting toilets use microwaves to heat the waste, but there are no such systems currently in production or commercial use. However, if excess heat was generated from an industrial composting toilet, it could produce hot water for other services on site.

Vermicomposting Toilets

Vermicomposting toilets are another form of composting toilet and one which has been used on a number of projects around the world, including Macau Tower, Hong Kong, SeaTac Airport Seattle, USA, Kansai International Airport Japan, Harbour Place Towers South Africa, The National Palace Museum Taiwan, Westin Hotel Beijing Chin, Christchurch Botanical Gardens New Zealand and others.

Up-Flow-Down Toilet

Another type of composting toilet is the UFDTs (Up-Flow-Down-Toilet) which has been used in a large number of projects throughout the world, including apartment complexes in France, multi-family housing in Stockholm Sweden, natural burial grounds in Canada, and other types of rural houses. This type of toilet is known as “dry” because no water is added to it during processing. The idea behind their design is that the waste falls roughly 1m where it comes into contact with wood chips or straw, which are then placed on top to create an above-ground pile where composting occurs over time, roughly 6-12 months.

Top composting toilets for tiny houses

If you plan to build a house or plan on building something smaller than the traditional house, one of your concerns would be space. You will want to consider all aspects of how small you can make your house until it becomes comfortable for living. One aspect that should not be overlooked is the toilet because this will affect other areas in the home too.

If you are considering other tiny house toilet options besides flush toilets, then Composting Toilet might be an option to consider. There are many different types of composting toilets available for purchase, and some people have even gone out there and built their own DIY projects with other materials. But if you are looking for a solution already made by someone else, I would recommend buying a commercial composting toilet.

Of course, when you’re building a tiny house, every cent counts, and it’s essential to find a solution for your needs that is affordable also. In this article, I will review some of the different types of toilets available on the market. Still, most importantly, I want to show you which one is my favorite option in terms of price and functionality so let’s get started!

The Nature’s Head Composting Toilet

The best option I recommend is Nature’s Head self-contained Composting Toilet system. It’s a Sawdust-free design that uses peat moss as a compost medium for processing human waste into a usable product. The peat moss can be easily replaced after being used up to a couple of years. The actual time depends on usage.

Nature’s Head Self Contained Composting Toilets

The Nature’s Head model is small and compact, very easy to install in your tiny house. The installation guide is clear and straightforward. There are two models available: Standard & with macerator pump. I recommend the standard model without a pump because you will need an external compost container or tumbler, so it doesn’t make much difference having or not having the pump. The pump saves you some space, but the cost is increased by $100.

10 Best tiny house Composting Toilets 2021

Composting toilets are the best option for tiny houses because they’re easy to install, don’t require any water source or electricity, and make use of organic waste rather than flushing it down the toilet. And if you want to start composting your own food waste at home, you can always get one of these toilets along with your compost bin.

Sun-Mar Compact Self-Contained Composting Toilet

If you’re looking for an ideal and suitable way to live off-grid, then the Sun-Mar Compact Self-Contained Composting Toilet might just be what you need. This means that it’s the best composting toilet for off-grid. This unit is designed specifically for off-grid homes and requires no water hook-up, which is ideal when there’s no reliable power source in place either. It runs on batteries, so remember to keep them charged, and you’ll be all set.

Pros and cons

Pros

  • Designed for up to four persons
  • Perfect for tall and short people
  • Built with an emergency drain
  • Its 100% non-polluting
  • It has a vent stack of 2 inches
  • It’s completely odorless
  • The fan works excellently
  • Minimal nuisance

Cons

  • Some people say it is not the best quality
  • Relatively expensive

Sun-Mar NE Self-Contained Composting Toilet

This self-contained toilet is similar to the one above, but it also comes with a solar panel that can provide up to 4.5W of energy for lighting purposes at night. So if your off-grid home doesn’t have electricity yet, this unit might just be exactly what you need. According to the tiny house composting toilet reviews, the Sun-Mar NE self-contained composting toilet is a great option for off-grid customers. It works for RVs and tiny houses.

Pros and cons

Pros

  • Designed for up to four persons
  • Perfect for tall and short people
  • Built with an emergency drain
  • Its 100% non-polluting
  • Has a vent stack of 2 inches
  • Its completely odorless
  • The fan works excellently
  • Minimal nuisance

Cons

  • Some people say it is not the best quality
  • Relatively expensive

Nature’s Head Self Contained Composting Toilet System

If you don’t mind paying a premium price for a composting toilet, then the Nature’s Head Self-Contained Composting Toilet could be what you’re looking for. This lovely little unit works great and provides an adequate of space in its compartments. The only downside is the price, but you get what you pay for, I guess.

Pros and cons

Pros

  • Excellent Customer service
  • Easy to empty
  • 5-year warranty
  • Space-saving design
  • Solid Build quality

Cons

  • Very expensive
  • Not perfect for relatively larger tiny houses

Neo-Metro C-Head

If you plan to replace your old toilet with a self-contained composting model, then perhaps the Neo-Metro C-Head would be an excellent candidate. This unit has a very small footprint, and it comes with a waterless flush capability which provides 80% of the flushing power of a standard flush toilet. It’s also quite affordable, and there are no ongoing costs associated with it like other composting toilets out there might have (e.g., sawdust, electricity).

Pros and cons

Pros

  • It comes in different models
  • Affordable
  • Suitable for small and large spaces
  • You can go for the churning or non-churning system
  • There are DIY options for tight spaces

Cons

  • Lack of enough information about the toilet

Nature’s Head Dry Composting Toilet System

The Nature’s Head Dry Composting Toilet system is another excellent composting toilet system that is suitable for most homes. It’s also very lightweight and comes with a small footprint, plus it also has the waterless flush capability. Another significant aspect of this unit is its ability to work passively without requiring electricity or costly ongoing maintenance costs.

Pros and cons

Pros

  • This product is environmentally friendly
  • Its containers are large
  • Easy to clean and empty
  • Comfortable to use
  • Suitable for short and tall people

Cons

  • Its relatively expensive
  • The installation process is tedious

Evolution Excel Euro Compact Composting Toilet

The Evolution Excel Euro Compact Composting Toilet is also another great choice due to its ultra-lightweight, compact design, and minimal-sized footprint, making it ideal for RV’s. Besides providing fresh air ventilation, these superbly built composting toilets provide an impressive flushing fluid with 80% flush power of home toilets. This unit is available in Europe, so if you’re looking for one, you might want to try getting it while you’re there.

Pros and cons

Pros

  • Compact design
  • Provides fresh air
  • Ultra-light
  • Minimally sized footprints
  • Cheap 80% flush power of the home toilet

Cons

  • Lack of enough information online
  • Poor customer service

The Sun-Mar Excel Self Contained Composting Toilet

Another great choice is the Sun-Mar Excel Self Contained Composting Toilet which uses no outlet pipes for easy installation and very little maintenance costs. This unit has an optional gray water system to use in combination with your sink. Besides its good features, this toilet also comes with a 6-year warranty, so you’ll be sure to get full value for money, especially when purchasing it online through Amazon.

Pros and cons

  • Unique features that eliminate the smell
  • Thermostatically controlled heater to evaporate fluids quickly
  • Odorless
  • Rear fan to help with evaporation
  • Effective evaporating chamber
  • NSF standard 41 certification

Cons

  • The process is precarious
  • It’s not wide enough

Clivus Multrum Composting Toilet System

The Clivus Multrum Composting Toilet System is yet another excellent composting toilet that doesn’t require electricity or any costly ongoing maintenance costs. What’s really remarkable about this toilet is that it doesn’t need to be connected to any sewage, septic, or water system.

Another thing worth mentioning about the Clivus Multrum is that it’s suitable for new construction as well as renovations and can even be installed by just one person. The only painstaking drawback is that it’ll cost you more than most other composting toilets patents, but it’s definitely worth every penny because of its durability and ease of maintenance.

Pros and cons

Pros

  • It doesn’t require a lot of water
  • Aerobic bacteria to convert waste into fertilizer
  • Reduced water demand
  • Odorless
  • Good reviews

Cons

  • Expensive

The Lovable Loo Composting Toilet System

If you’re diligently looking for a composting toilet that will also save space, look no further because the Lovable Loo Composting Toilet System has everything you could ever want in a tiny package. It fits into tight spaces, has a top-hinged lid that makes removing solids easy, and is entirely self-contained.

Pros and cons

Pros

  • The product is safe even for people with disability
  • Mostly unobjectionable handling human waste
  • Easy to build and use
  • Minimal odor
  • Exceptionally cheap

Cons

  • It’s not suitable for apartment dwellers

Sun-Mar Centrex 3000 NE (Non-electric)

This is another excellent unit composting toilet, but this one uses dry material instead of liquids. With this unit, you can get rid of all your worries about liquids. It automatically separates liquid from solid waste, and only the solid remains. The solids are stored inside an air-tight Dry Composting Toilet System, which can continue to be used at least three years before you need to empty the bin.

This system is made of higher quality materials and can be used in a number of ways. It can be placed inside the house or directly outside. It is also effortless to install with an inclusive instruction manual. Special tools needed for installation are included in the package.

Pros and cons

Pros

  • Self-contained
  • Non-electric
  • Can handle up to 5 adults
  • You can empty the toilet after every few months
  • Installation for offgrid
  • Best for short people and people with disability

Cons

  • $2,149 on Home depot is not a cheap investment

Who’s the best Manufacturer of Compositing toilets for tiny houses?

With all the information above, you definitely want to know who the winner on the list is. The fact remains that Nature’s Head Brands are the best for all the good reasons. Here are the reasons why we recommend Nature’s Head Composting Toilets.

The seat and cover of Nature’s Head toilet

The seat and cover are of good quality and solid built. So you don’t have to worry about any damages while sitting on it even after many years of use. There is a vent fan installed, which you need to run for only a couple of minutes after using the toilet. It will pull out most or all odors from the air into the outside of your tiny house. The smell is almost unnoticeable when the fan is running.

Nature’s Head composting chamber

This part contains a plastic container with two chambers separated in half lengthwise, with a screw-in/out separation piece in between each side to be removed separately. The upper chamber is called ‘Carbon Filter’ and is designed to sit right below fan housing with its carbon filter lid up against the assembled fan.

The bottom half of composting container

This side is designed as a storage space for a separate bucket, where most urine goes. There is an additional screw-on cap under the main cap, so you can have two different containers for the liquid part and solid part, or just use one container if you want.

In order to keep the smell down, this compartment needs to be filled approximately 2/3 way full with dry material such as peat moss, coco coir, etc., before adding any waste materials. It will take a couple of days to adjust to the moisture level generated by the composting toilet. It will need to be emptied when full, and then the process must start all over again with fresh material added for it not to smell bad. A separate container (not included) is also needed to collect any liquid that might be generated from an external source, such as a manual flush waterless urinal, ultraviolet light sanitizing system, etc.

Composting container

The bottom of this part has a little grate-like thing that needs to be removed and replaced every time you empty or add new waste materials. I found out that it’s pretty pointless, doesn’t really serve any purpose since the urine mixture is allowed to drip through this area very quickly. Bottom line; toss that useless thing into the bin.

Fitting lid to the container

Pretty self-explanatory, I think. Just ensure you leave enough room for when you lift off this part when it’s time to empty the contents of the composting or when adding new materials. This model does not have a manual or electric flush system. So, in order for it not to smell bad, these are the steps needed every time you use it;

Add in organic material regularly (green kitchen waste, garden weeds rich in nitrogen, shredded paper). About 3-4 times a week is more than enough. Once done with your business, quickly add one cup of sawdust (you can get this from any hardware store) and stir everything together.

Can Composting toilets take solid waste?

Some composting toilets are designed to take care of both human waste and used toilet paper, although this is less common than a toilet that only handles one or the other. These models generally have a removable receptacle for solid waste to drop down into before it is covered with a carbon-based substance such as sawdust, wood chips, coconut coir, peat moss, or rice husks.

If liquids are present, these types must be emptied periodically depending on the capacity of the unit and local regulations regarding clean water discharge. In some designs, liquids can be drained externally into an evaporation chamber where they evaporate without contact from the indoor air environment. This reduces odors and helps control insects and other vectors.

Higher-end versions of composting toilets are currently available in Europe, Australia, North America, Japan, and India. These types include built-in fans to speed up the composting process, large tanks for storage of solid waste or graywater, electric heating elements to manage moisture levels inside the compost chamber, or simply complex computer controls that monitor input conditions such as temperature profiles within the unit.

These models are sometimes known as “dry toilets” because they reduce water usage by controlling when liquids are discharged into the environment. A well-maintained conventional septic tank system is typically quite odorless. In contrast, poorly maintained systems can produce powerful odors because anaerobic bacteria produce hydrogen sulfide gas in the absence of oxygen, which is produced by the bacteria inside a septic tank as organic material decomposes.

Note that “blackwater” from toilets and all other wastewater from sinks, tubs, showers, dishwashers, and washing machines goes into the drain field as well as graywater from kitchen sink drains. But not the water supply lines themselves. In conventional Septic Tank Systems, one should separate wastewater from Kitchen Sinks & Disposal Units from WasteWater from Clothes Washers & Bathtubs because food particles should never enter a drainage system. This separation can be done quickly with a backyard compost toilet Cesspool systems are often used in remote areas where digging a holding tank for wastes is difficult or impossible.

How to buy composting toilets for tiny houses

Many different brands manufacture these kinds of toilets, but not all of them are made with high-quality products. Let me just mention some important points about what makes an excellent composting toilet for your tiny house:

Exhaust pipe

It must have a 10-inch vent stack (exhaust pipe) that runs all the way to the outside.

Size

Bigger is not better. In fact, it can be a problem when you have low ceilings in your tiny house. Most of the units mentioned below are small and compact but still efficient in processing human waste into composted material!

Quality

It’s without a doubt a good idea to invest a little more money in a quality product from a trusted brand name rather than buying cheaper models from unknown manufacturers. In most cases, they will fail after few months requiring you an emergency toilet situation that’s not only inconvenient but also very costly. So, don’t scrimp here!

Instructions

Read and understand all instructions and warranty information before buying and installation.

Designs

Toilets for tiny houses come in 3 different designs: flush-tank toilets, dry-composting units, and composting toilets that work with no need for water. Move your hand or foot to bring it down into the “V” shaped rubber gasket at the bottom of the bowl where deposits are made. That will be the water level. If your hand or foot can’t touch the bottom, you’ll definitely need a flushing toilet.

The no-water toilets are ideal for tiny houses because they don’t need any water supply and also take up little space. It uses a long plastic “tray” with three chambers to collect, dry and compost deposits. The two front chambers are filled with peat moss or other carbon-rich material as a filter for the toilet waste as it dries out, while the back chamber is where actual “composting” goes on. The whole thing gets covered over with a layer of soil every few days to complete the composting. A clear plastic “indicator” shows when the toilet needs to be emptied. A few brands of no-water composting toilets are available.

No water is also a good option for your outhouse if the garden already has one functioning septic system and you don’t want to add more load on it.

Conclusion

While some people find them tedious, tiny house composting toilets are excellent options for those seeking to live sustainably. A quality composting toilet generally doesn’t smell, and it’s affordable, eco-friendly, and easy to install and use. As a matter of fact, you might try out a composting toilet for your tiny house and discover it’s not as bad as perceived.

FAQs

How does a compost toilet work in a tiny house?

The toilets typically work by separating solid and liquid waste. The solid waste will go into a chamber where its mixed with mostly peat moss to speed up decomposition.

How bad do composting toilets smell?

Composting toilets tend to get a bad rap. However, most of them are designed in a way that people don’t have to deal with odors. In fact, compost toilets don’t actually smell and they are similar to any kind of toilet.