Toilets for Tiny Homes

The type of toilet you choose to install in your tiny home will definitely affect things like your budget, your other systems, and your ability to travel. It's a question that I get from time to time, so I thought I would share this short and informational session with you. I am talking through what I chose for my tiny house, the different types of toilets that exist, how they work, and the pros and cons of each.

In This Episode:

  • Water usage and flush toilets in a tiny home environment
  • Waste water tanks and weight impacts
  • Alternative solutions to flush and compost toilets
  • Breaking down the pros and cons of commercial compost toilets
  • All about bucket-style compost toilets


Links and Resources:


Guest Bio:

Ethan Waldman

Ethan Waldman

Ethan Waldman is a tiny house author, speaker, and teacher. He built his own tiny house on wheels in 2012, and has been passionately helping future tiny house dwellers on their own journeys ever since. Ethan’s guide, Tiny House Decisions, has helped thousands of readers answer the big questions about tiny houses and plan each system in their future home. He’s also the creator and host of the Tiny House Lifestyle Podcast, a show that brings you conversations with tiny house luminaries, builders, and DIYers.

This Week's Sponsor:

Tiny House Engage Community Group

Tiny House Engage

Tiny House Engage brings together tiny house hopefuls and DIYers to share plans and resources, learn from each other’s challenges and mistakes, and celebrate our successes so that we can feel less alone while we build faster, safer, smarter, cheaper homes and embrace the tiny house lifestyle. Whether you’re a tiny house dreamer who is still figuring out all the systems, plans, and everything you need to go into your tiny house, or if you’re actively building, Tiny House Engage has the resources for you. There are professional contractors in the community here to answer your questions about plumbing, electricity, and ventilation, and there’s also plenty of interaction between members. If you need some encouragement or just need to know how someone else solved a problem, you’ll get those answers in Tiny House Engage. I’m also very active in the community, answering questions and keeping an eye on things, so if you want to interact with me, this is a great way to do it. To learn more and register for Tiny House Engage, go to


More Photos:


Tiny Home on Wheels

Tiny House Bathroom

Secluded Tiny House with Wheels


Ethan Waldman 0:00

Welcome to the Tiny House Lifestyle Podcast The show where you learn how to plan, build and live the tiny lifestyle. I'm your host, Ethan Waldman, and this is episode 281, with me, Ethan Waldman. This always happens this time of year, it's September. And people are just kind of transitioning back from summer mode to fall and winter mode and it is so hard to get people to commit to an hour long interview for the show. So this week, I will be sharing a session my session from the 2022 Tiny House summit that I put together all about different types of compost toilets for tiny houses. It's a question that I get from time to time about, you know, where the pee and the poop goes. And so I thought I would share this pretty short and informational session with you where I go through what I chose for my tiny house, and also what the other options are out there. I hope you enjoy the show and we will be back next week with our normal format and interview with a tiny house dweller.

And if you enjoyed this session, then go to That's Where you can see the whole lineup, there are 30 speakers, 30 sessions. And if you want to get recordings of all 30 sessions, click on that link that says all access pass and then use the coupon code THLP. At checkout, you will get 30% off your all access pass just for telling us that you came here from the podcast. Check out that all access pass where you get 30 recordings from all 30 sessions. Use the coupon code THLP for 30% off.

All right, let's dive in. Welcome to the tiny house Summit. I'm your host, Ethan Waldman and this is my session on compost toilets. One of the most hotly debated aspects of tiny house living is kind of what to do about the pee and the poop. So what to do about your toilet in a tiny house poses some kind of additional challenges compared to what you might have in a normal house.

So I'm actually going to start before compost toilets and just talk about standard flush toilets, and RV flush toilets because they're kind of two branches of this similar branch.

So a standard flush toilet is the same thing that you would find in any normally sized house. While they are there are some small ones and you could fit one into a tiny house, they're not exactly ideal. They require a big hole in the floor and specific plumbing beneath them. Plumbing that wouldn't be very easy to install having hanging down under the trailer. Basically, your your flush toilet has a P trap underneath it, you know one of those U shaped things that needs to be below the toilet. So you either are going to need to build the toilet up onto some kind of box, or you're going to need to have that underneath the house. Standard toilets are also very water intensive.

A standard flush toilet uses about five gallons of water per flush. So if you manage to fit a 40 gallon freshwater tank into your tiny house, then you're looking at just eight flushes until your tank is empty and that's assuming that you don't use any other water. The other problem is where does all that water go. Unless you are directly hooked up to like a septic system or a source system you don't really have the ability to use the toilet.

There are modifications to a standard flush hood that are designed for RVs RV flush toilets work on a similar common concept you know you you do your business into some water and then you flush that water mixed with your waste away and they use less water than a conventional toilet.

But the big question is where does all this water go when an RV or a tiny house flushes a toilet. So most RVs come with two holding tanks so they are installed usually below the floor there's a gray water holding tank and a black water holding tank. Grey Water is considered any used water from the sink and the shower. It's you know it's dirty water but it's not contaminated with fecal matter and urine. Blackwater comes from your toilet RVs have holding tanks for both kinds of water with ports on the side of the vehicle. And so they are essentially able to carry their wastewater around until they get to the appropriate dump station. Yep, that is what they're called. And that's where they would empty their tanks.

So while this setup is technically possible for a tiny house, it's not a great solution, it's not a likely solution. I can think of lots of reasons why. But the number one I'll mention is the weight. One gallon of water weighs about eight pounds. So if you have a 40 gallon freshwater tank, a 40 gallon gray water tank and a 40 Gallon Black Water tank, and they're all full, that would add almost 1000 pounds to the weight of your house, it's about 960 pounds. So since tiny houses are not made of lightweight materials, they're often right on the edge of what what trailers can hold. So I know that if I added that much weight to my tiny house, I'd be overloading my trailer, which is rated at 10,000 pounds. The other thing is just that tiny houses on wheels, at least while they are movable, it's not exactly easy to move them. And if you've got a 40 Gallon Black Water Tank that needs to be emptied every week or less, that's going to be a lot of moving of your house. And that's pretty inconvenient.

Now, there are alternate options. There are portable Blackwater tanks, it's essentially a tank with wheels on it that you could hook up. But again, you're going to have to move that tank, you're gonna have to roll that giant tank of pee and poo, put it into the back of your pickup truck, bring it somewhere, have it pumped out clean it, etc. It's it's not an ideal option. And I hope I have convinced you to seek an alternative toilet setup for your tiny house.

So what I'm going to do is talk through the options other than a compost toilet, and then we're going to talk about compost toilets. So the first option that that I want to talk about are dry flush toilets. This is a portable toilet and it hit the tiny house seen around 2012. I've heard it described as the Diaper Genie of tiny house toilets. Essentially, each time you use it, you're gonna put a single use plastic liner down in that tub. And when you're done, this vacuum power drum spins and compresses the liner into a neat little package that you throw away in the garbage. Other than all the waste you'll have to deal with. The obvious downside of the dry flush toilet is that their refill bags are only good for about 17 flushes like the pack of refill bags, costs about $54. That's over $1 per flush, which I don't know about you, but I don't want to have to spend $1 Every time I use the toilet. So those are dry flush toilets.

Then there's something called incinerating toilets. incinerating toilets take whatever you put in and literally literally burn it, though they are waterless so that's good. And they don't lead to too much pollution in the ground. They do release some smoke. And they they burn fossil fuels either in the form of propane or electricity to literally burn your poo. I don't recommend them. And there are some kind of gnarly videos on YouTube that you can check out that that kind of show the process for using and maintaining an incinerating toilet. I will say incinerating toilets do have a following there are people who love them.

So I would say you know do your research. If you have a chance to try these different things out, I would try them out. But any toilet that relies for me on electricity in order to flush that's a little bit of a non starter for me just knowing that if I was ever off grid or I had a power outage, I would I would definitely want to be able to flush my toilet.

The last one to talk about are chemical toilets. So chemical toilets for RVs. And Tiny houses are like kind of the the little siblings of the blue porta potties that you see at construction sites. You do your business into a vat of, you know, terrible dyes and deodorizers and then you eventually have to empty them into some kind of septic system or waste treatment system. In my opinion, they combined the worst of both worlds you have to manually remove the waste and you're polluting the Earth with the the chemicals that it all gets mixed into when you put it down the septic pipe. So I would say to avoid chemical toilets.

Okay, so you might be wondering what kind of toilet could be left for your tiny house? The answer is composting toilets. These are by far the most common type of toilet found in tiny houses. The compost toilet has many advantages over its conventional counterparts and I highly recommend considering them. And just a note I highly recommend reading the Humanure Handbook by Joseph Jenkins. I've actually had Joe Jenkins on the Tiny House Lifestyle Podcast and we'll link to that interview. One thing that I learned in that interview which I did not have in my book Tiny House Decisions is that the the name composting toilet is a misnomer. It actually is a compost toilet. The reason being is that the composting doesn't actually happen inside of the toilet. The actual composting happens outside of the toilet in a pile in a compost facility. The toilet itself is just a collector.

And we're going to talk a little bit more about that because some of the commercial composting toilets are the compost toilets make claims that they actually create compost really quickly and they really don't. So I'm not going to attempt to get into the chemistry or physics or philosophy behind compost toilets because Joe Jenkins has already done the definitive work. So definitely read the Humanure Handbook, Joe Jenkins kind of breaks down the problem, which is the way that we currently handle waste in our society leaves us with a broken cycle that doesn't replace the nutrients that we're taking from the earth. It sounds very hippie dippie. But he devotes most of the book to a very well researched and kind of footnoted account of how compost works, and more importantly how it works on human waste. And the book will satisfy both your inner scientist and your inner hippie so I still I've you know, plugging it again, check out the Humanure Handbook. compost toilets come in two main types.

There is the commercial compost toilet and then the bucket style compost toilet. So the commercial is something that you buy the bucket style is something that you can make. So let's go into commercial composting toilets. They are a special device usually made of plastic, they handle both waste collection and sometimes the actual composting process. But again, it's more of a drying process. waste goes in and some kind of compost comes out a few weeks or months later.

Here are the pros. So I'm going to do a little pro con thing. So the pros of the commercial composting toilet. So Pro Number one, they reduce your contact with the waste. The biggest pro of the commercial compost toilets is that they minimize the frequency with which you need to interact with your waste. That's point number one.

Number two, they don't require any special plumbing. Since your compost toilet doesn't use water to flush away your waste, it doesn't need a water supply. It doesn't need a drain, etc. That actually record that actually represents a significant cost savings on your plumbing setup. So you'll get this benefit with both commercial and bucket style toilets. The feature of compost toilets that kind of let me isolate all my plumbing to my cabinet underneath my sink Kitchen Sink was the fact that it did not need any plumbing of its own compost toilets.

Benefit number three, they are environmentally awesome. Since you're letting these magical micro organisms break down your waste and turn it back into soil, you're not polluting the ground or the drinking water supply. Pro Number four, they look clean. The perception of a commercial composting toilet is something that looks clean and aseptic. If you're worried about appearances, a commercial composting toilet will be probably less intimidating than the bucket style. Alright, so those are the pros of the commercial compost toilet.

Let's talk about the cons. So the biggest cons number one they are expensive to buy. These things cost a small fortune between 1003 $1,000 for the unit. Plus, sometimes there is additional cost to install special ventilation that they require more on that in a moment. And you're paying all this money for something that nature does for free. And that you can do with a $4 bucket from your local hardware store.

Con number two, they usually have electricity and ventilation requirements. So as I just mentioned, commercial composting toilets require special ventilation plus some require electricity to run. So what happens if you have a power outage, that ventilation fan stops running and things can get stinky?

Okay, con number three is that commercial compost toilets don't don't produce real compost. They will tell you that they do but they don't. Most commercial compost toilets don't produce the true compost that you could use to fertilize your garden. Many of them just use fans and sometimes heating elements to speed up the drying process and dry out that waste. The leftover material won't smell once the moisture is removed but it should still be treated as potentially hazardous to human health and probably shouldn't be put in your garden.

Con number four, you can reach capacity. The commercial composting toilet has a capacity and if you overfill it the compost features will be inhibited or stopped entirely. So this is a mandatory stop what you're doing and empty the compost toilet.

Alright, let's talk now about bucket toilets. Compared to commercial compost toilets, the bucket style toilets are very simple devices that handle just waste collection. The actual composting process takes place in a separate location in a compost pile that you manage. It's Joseph Jenkins in the previously mentioned Human or Handbook who details the process of how to own and operate a human or toilet. Simply put the rules are whenever you go add a scoop or more of sawdust or another fine natural cover material until whatever you've deposited in the bucket is well covered. If it still smells, you add more cover material until it doesn't smell. When the bucket is full or nearly full, you bring it outside to your compost pile and empty it into the center of the pile. You cover your compost pile with a coarse cover material like straw or hay. And that's it. If you've never used a bucket toilet before, you're just going to have to believe me when I say that it doesn't smell so and this is the kind of toilet that I have in my tiny house.

So let's talk about the pros of the bucket toilet. They cost less Pro Number one, they cost less than $100 to build. You know the low price tag frees you up frees up your funds for other nice to have appliances or other other parts of your build.

Pro Number two is that they produce real compost that you can use in your garden. You know, be sure to read the Humanure handbook for more info on how to be sure that your compost is actually ready for garden use. But it is possible and I have done it and I've lived to tell the tale. They won't run out of space. So if your bucket is full and you don't have time to empty it, put on that tight fitting plastic lid that you buy along with the bucket and replace it with a new bucket. It's really easy to have extra buckets on hand because they only cost about $4.

And then the next pro is that they're easy to install. Bucket toilets don't require any electricity or special ventilation to be effective. So you can as long as you can build a box with a lid and cut a hole in it. You can have a bucket toilet too. Okay, so as you can tell I'm a fan of bucket toilets.

But let's talk about the cons of the bucket toilet. One is that you're going to need a lot of cover material. Luckily for me in Vermont, there are sawmills there are actual steel sawmills to choose from and my current favorite place is allows me to fill up a 50 Gallon Trash Can with pure untreated sawdust for free. I've also reached out, I recommend having multiple sources, so I also have a local woodworking school. They don't use any pressure treated wood. And that's important. You don't want to use sawdust from like pressure treated wood. They let me every every month or two they give me a giant trash bag full of the shavings from their joiner that I that I kind of mix in with my sawmill sawdust. And you know that of a 50 Gallon Trash Can full of sawdust lasts about I'd say about a month of full time use.

The second con is that they require more frequent emptying than the commercial models. So you can expect to be emptying your compost toilet upwards of once per week, potentially more if you've got multiple people using it. With a commercial compost toilet, it may be closer to a month between emptying.

And the third con which is actually probably the biggest one is that you'll need a compost pile. Since the bucket toilet doesn't handle any of the composting itself inside. You need to bring your waste to an external compost pile where it will decompose along with your food scraps hopefully, and other organic matter that that actually helps. Fortunately, it's perfectly legal to have a compost pile in all 50 states. If you're planning on moving around a lot though, you're gonna have to build one each time you park your tiny house. And since compost works over time, you won't ever get the benefit of your labor. So you'll just be leaving behind piles of well. sawdust and poop and pee.

So, you know as you've probably guessed, you know I went with a compost toilet in my tiny house, a bucket style and and I love it. It's the it's the method that I recommend and I I know people who have actually switched from the commercial style back to a bucket style and so what's great about this is that you can actually try it out wherever you are before you even start. You can go on to Amazon or Walmart or wherever you can buy a toilet seat that will fit right onto the lid of a five gallon bucket. Get yourself a bag of sawdust or shavings or anything like that. You can use peat moss but it's not environmentally friendly. Give it a try. See See what you think of using a compost toilet right in your are right in your bathroom or living room. Alright, well that's, that's my session on compost toilets. I hope you've enjoyed it and I hope you love the rest of the summit too.

Thank you so much for listening to the Tiny House Lifestyle Podcast this week. Again, if you enjoyed that session and you want to gain access to 30 expert sessions from the tiny house Summit, head over to tiny house and click on All Access Pass, then use the coupon code THLP to get 30% off. We'll put both of those links down in the show notes for this episode. That is all for this week. I am your host, Ethan Waldman and I will be back next week with another episode of the Tiny House Lifestyle Podcast.

powered by

Subscribe to the Tiny House Lifestyle Podcast: