Composting Toilet

Following is a guest post by Walt Barrett.

I promised that I would write an article about the composting toilets that we build, so here it is. It includes my idea of a sliding adjustable urine separator.

The customers that we have using this toilet are very happy with it.

One of the main killers in the world is contaminated drinking water. In third world counties people can be very careless about where they dispose of their fecal matter. The sad results are disease followed by death usually from Cholera! This is because the runoff from this human waste is polluting the streams, rivers and lakes in those countries. We don’t need fancy units to solve this problem. All we need is to convince people to properly dispose of their own waste in a composter protected from the rain to prevent runoff. You would think that at least in the last 5000 years the could have learned that.

Well this is our version of the composting toilet for the off grid home so that you can have the indoor convenience and a safe, economical disposal method for human waste.

Please read this and don’t skip any steps or you will ruin the project.

It’s tricky in a couple of spots to get the unit in square.

This is a relatively simple unit to build and I am just going to take you through all the steps right now. My son John and I sketched out the design we had been discussing for a practical composting toilet, and figured out the dimensions that we needed to fit the actual standard toilet seat and make room below for the two plastic collection bins and the vent stack. We also wanted to build as many units as possible from a single sheet of decent quality 3/4 inch plywood. While at the Home depot we had a 4′ x 8′ sheet of plywood ripped into three long pieces approximately 16” wide each. Those cuts must be exact so all three lengths have the same width. Home Depot or Lowe’s will use a panel cutting saw which will make perfect cuts if the sheet is measured correctly. Note that due to the width of the saw blade the width will be slightly under 16”. You can compensate for this on assembly by assembling the pieces so that the box is slightly narrower than 16”

Next we cut two 16” wide X 16 inches high for the two (2) end pieces.

That leaves the two sides, the bottom, and the top. Now this is where you have to be careful. Look carefully at the construction of the box in the photos. We cut the two side pieces 22 inches x 16 inches high. That left the top and the bottom pieces which we cut 23 ½ ” inches long. Now we have all the pieces and that leaves us to position the store bought toilet seat and trace the hole in the top cover. I use the larger and better oval type toilet seat that fits the better quality toilets that you find in better homes and all commercial applications. They are much more comfortable for adults. I then drill a 3/8” hole for the saber saw, and cut out the hole in the top of the box. Make sure the hole is back far enough to accommodate the urine collector drain bin.

Now let’s stop right here for a minute and make a cutting schedule.

All pieces are ripped 16 inches wide. It allows you to get the most toilets from one sheet of ¾ inch plywood. So here is the schedule. ” = inches.

2 End Pieces 16” x 16”
2 Side pieces 22” x 16”
1 Bottom piece 23 ½” x 16”
1 Top piece 23 ½” x 16”

At this point it is best to sand, and clean all the pieces off with paint thinner. Because if you are going to stain your unit like we do here. You must stain before you start using the wood glue. If you don’t stain first, wherever you get glue on the wood the stain will not take and it looks terrible.

After the stain is thoroughly dry I use a couple of brads on each end and lightly tack the four sides together while just sitting on the bottom piece just to check for fit, and using a large metal square I make sure it will square up in three directions. You could also measure diagonally from corner to corner for equal dimensions in two directions. Then set the top on Just to make sure it fits squarely.

Once you are satisfied with all of the workmanship and the fit of all the pieces, it’s time for the permanent assembly. This is how we do it.

  1. Set the four sides that are lightly tacked together on your flat work bench surface.
  2. Remove one of the ends that you have tacked on and tap the finish nails that were holding it back away so that you can hammer them in again easily.
  3. Then run a thin bead of quality carpenters glue down just off center favoring the interior of the box. Do not use too much glue as it will squash out all over your finish. Thats why you always favor the inside edge. You cannot stain over excess glue blotches.
  4. Now careful pet the end cap back in place and nail it securely with six long finish nails on either side.
  5. Repeat the process on the opposite end.
  6. Next you run a bead of glue around the rim where the bottom of the box will be nailed.
  7. Set the bottom on and while someone helps to hold the box square you nail on the bottom using long finish nails about every four inches. It is very helpful if you nail a couple of cletes to hold the corners square while you nail your box together. Corner cletes on either end will also hold your box square while the glue is drying. If you have clamps, use them too get a tighter glue joint. You can also take a length of rope and wrap it around the box , make a loose knot, insert a length of stick and twist the rope until you get several pounds of pressure on your joints.
  8. Be sure to wash off any glue that squeezes out of the joints immediately.

That leaves us with the top which never gets fastened down because it has to lift on and off to remove both of the bins for cleaning etc. the lid is kept from sliding around by use four pieces of aluminum angle tacked inner the rim on the center of each side to provide a snug fit to the box. That way the lid is easily removed for cleaning purposes. See the photos for the aluminum pieces.

Now you have built a regular composting toilet without a urine separator. We got our plastic collection bins from Walmart. We purchased a smaller fairly deep bin for the urine collector. We got the fittings and clear plastic ½ inside diameter inch drain hose, and clamps from the plumbing department at the home depot. The drain hole goes out the side of the bin and box as high up as you can get it without kinking the hose and still get a good gravity feed to your exterior collection system. The brackets are made from the flat perforated metal plated to buy at the home depot that are use for building decks and joining pierces together for various construction projects. I bent then to the shape I wanted using my bench vise and a rubber mallet. Be careful for sharp metal edges! If you want a vent stack you can put it in one of the rear top corners or elbow out of one of the rear sides, or end. It the best way to go and add a solar vent fan too.

This is a pretty good project for a beginner, but believe me, manufactured units go from $800.00 to $2,500.00 dollars, and thats a lot of money for a person on a budget. This unit will work just as well. Just keep a spray bottle around with a little bleach and water in it to freshen up the urine catcher after each use. You can cover the fecal matter after each use with any kind of dries vegetable matter, like saw dust, Pete moss. Dried leaves, dried grass etc. Just don’t get bleach water in the composting material.

You can empty the compost into a barrel with a watertight lid on it. If you are going to introduce earthworms to the compost you have to keep it moist without drowning the worms. Be sure to make provisions fore the composter to drain excess fluids into more compost beneath it. Never compost anything near your water supply. Keep the composter as far away from you well as possible. After a couple of years the compost will turn int rich black soil. Throw all of your table scraps into the outdoor composter too.

Well, I think I covered everything. If I didn’t, I’m counting on you all to let me know.


© 2010 Walt Barrett

60 thoughts on “Composting Toilet”

  1. I must confess I had to make myself read the article, because I have no immediate need to build this. But having read the humanure handbook, this seems to go at odds with the advice in that book, though I’m sure there are many workable ways to make a composting or otherwise very simple (and much cheaper) toilet solution.

    He says that there is no need to separate urine, for instance. It contains nutrients that can be used in the composting process anyway, though I suppose it increases the amount of sawdust you need.

    You might want to cut out the bottom of the drum, to allow earthworms and other critters into the compost, and not put the watertight drum lid on (you need to water to the pile every now and then, might be able to get away with the rain doing it for you). I would think you would need several drums if the stuff is to be stored for a year.

    • Of course, we’re biased and we’re going to say a composting toilet is the best type of toilet for a tiny home, but when you think about it – when you’re reducing your impact on the earth, reducing your living costs and trying to live a simplified life, a composting toilet is the perfect solution for your next tiny home project.

  2. Good idea nice and simple. I am a little concerned about the bleach. Inhaling vaporised bleach and adding it to your compost gives me pause. I understand it evaporates but that is not the end of the story. While it is unlikely that household bleach will become organochlorides even that leaves other concerns for killing off the microorganisms you need for composting or the potential of threats to wildlife. The threats are minimal but some people choose not to use bleach on a regular basis. Also, the production of bleach and plastics is pretty harmful as well. I’m no saint and i’m not preaching. I use it when i need to (i don’t want salmonella or cholera etc.) but for my composting I rely on saw dust and small wood chips which are good for moisture and odor too. A natural citrus oil will keep your urine catcher smelling like florida oranges. Good job.

    • Brook, the article specifically stated to bleach only the urine holder to keep down the smell, but absolutely do not put the bleach in the compost. Here’s that part, “Just keep a spray bottle around with a little bleach and water in it to freshen up the urine catcher after each use. You can cover the fecal matter after each use with any kind of dries vegetable matter, like saw dust, Pete moss. Dried leaves, dried grass etc. Just don’t get bleach water in the composting material.”

  3. Hi Parrot Whisperer,
    Our experience is that excess urine tends to build up and the odor gets really objectionable. We do not want rain washing our compost into the soil prematurely. Liquid is added to an outdoor composter as needed and worms are always part of the process. WE have had people try cat litter, but it is difficult to dispose of as it is really not very compost-able.
    Collected urine is a good way to go to moisten the barrels, but not in the house, and i wonder how many people would bother anyway. . I’m sure we will be getting a lot more comments to study. Let’s hope they are helpful.
    Thanks for commenting,

    • We have over 1,000 people using composite toilets and will produce 3 tonnes of grade A compost this year.

      We find NOT separating the urine is easier and works better.

      We use [recycle] old 5 gallon paint buckets and have currently 500 in use – with 50 compost toilets.


      About to build 36 more new units for a new Eco Resort which will be using some humanure for composting and the rest for a Bio digester to produce Biogas for hot water, cooking and some power generation.

      Happy to advise if anyone needs help as we have been using them extensively now in large numbers with over 1,000 people for 2 years!!!

  4. This looks good and the urine separator seems like a good idea.

    Won’t the tub will be hard to grasp and move once its full? Have you filled a tub? I realize its possible to empty before its “full” just thinking that the handles are not well placed for this use (unlike 5 gallon bucket).

    I would paint the inside making it easier to clean. And make sure the hole under the seat is as large as possible to avoid having “spills and splashes” on the plywood parts.

    Beware adding kitchen scraps to outdoor composter if you don’t want to attract wildlife – everyone from rats to bears.

    PS its peat moss not Pete moss.

  5. Just want to thank Walt for sharing his composting toilet project and Kent for posting it here.
    I follow the tiny house blog with every post.
    I bought a piece of heaven, with a birds eye view of Lake Superior, in Minnesota’s northeast arrowhead region. I had to have a safe septic system in place when I placed a permanent dwelling on the land. So, because of my limited funds I chose a composting toilet and purchased a Sun-mar that was approved by the state. Since then, my tiny dwelling I had built is not finished and the toilet has not been installed, so I’ve been reading up on composting and using a porta-potty. I just use the compost concepts I’ve learned online and it is amazing how simple it is. Using mulch and sawdust as it’s used, there is no odor at all. Only problem is moisture, but the full size unit will handle most of that. Walts idea is good for adding a separate urine basin to separate, because urine itself is perfectly safe. Only when mixed with feces does it become contaminated. I’ve seen some blogs promoting unisex urinals that drain to a barrel dug in the ground to filter back into the soil. Also, ammonia and water is probably a safer solution to cleaning the urine container.
    Great post, thanks again!!

    • You might find some of the information on the CAT page about water and sewage useful for composting toilet and greywater treatment – though being in the UK CAT doesn’t consider quite the extremes of temperature we get in the Northern US and Central Canada.

      They have published a book comparing different waterless toilet systems, commercial and homemade, and I think the how-to parts are all on the web page.

  6. Now what’s funny? We talk about “glamping” and the whole world erupts.

    We talk about composting human waste?

    Squeamish topic, but I suspect most will be intrigued. I have had something like this go through my head (not literally) a few dozen times.

    Helps to see someone did it and has something to discuss.

  7. I built a humanure type toilet this summer (bucket style) and used it for over a week.I left it in my microhomestead where it was over 100 degrees daily.My wife did not know I was doing the doo!

    I invited her out for the acid test ODOR!Under the pretence that I wanted to show her my latest “improvements” to my project we stood in the 8×8 microhomestead for over 5 min while I gave her the tour.

    I finaly asked her if she smelled anything? she said yes.I said what? she said wood! We me and the poty passed with flying colors!!

  8. It all fits in with tiny housing- good post…I actually have a composting toilet video I filmed a ways back- I’ll have to eventually post it.

    The Jenkins’ book is great too- he pretty much sums up the US mentality of squeamishness and ridiculousness by stating “Isn’t it beyond wasteful that we go to such lengths to purify and chemically treat water, only to then defecate in it?”. Its true…. Drinking water’s another story, obviously.

    Anyway, I have a much simpler sawdust-style bucket toilet at home- works great- I even have won the wife over with it- she uses it now too. Most other people come down into my finished basement, see it, and ask “now when you go to the bathroom in it, doesn’t it stink?” -To which I reply “Its full of piss n’ sh-t right NOW” (well, not in those exact words).
    No odor- I use saved sawdust (not p.t., painted, or stained) from my projects- and compost it in the backyard- closest to the neighbor who I don’t like (kidding).

    Cool twist/design on composting toilets though- again, the more the merrier…

    All in all, these things are great, especially on a budget, for cabins and tiny houses- boats too…


    • There is a wide gap between rural living and where the vast majority lives in high density urban locations. Sanitary engineering has solved a very real problem when you consider cholera was a major urban health crisis 100 years ago. Reverting back 100+ years is not a solution. Since the overwhelming population does not have a garden much less access to composting, bucket sanitation has very limited application. In these cases there are laws to protect us from our selves.
      There is no reason to separate urine from any other organic waste as it breaks down into ammonia and eventually nitrate, contributing to the nutrient value of the final product. Moisture content is tricky in composting toilets.
      In the indoors without venting from these types of systems off gassing consists of ammonia, hydrogen sulfide, methane and CO2. Even though this is not design to compost, decomposition does take place.
      I admire your attempt at tackling a problem especially as a segment of the population migrates to a simpler life.
      I design and build fluid treatment equipment and systems including water, waste, algae, food and more. My primary concerns are the recovery of water and recycling onsite.

      • I run a closed-bin (no runoff) composting toilet in a city neighborhood. If you keep the bin out of the sun in the hot season, the worms/microbes wont be killed… and it doesn’t smell either. I don’t typically separate urine, but I add extra sawdust to compensate. The people I know that separate have the nicest smelling toilets of all (can be used indoors, no problem).

        Yes, runoff is the issue. If you aren’t sure of your soil type and runoff conditions (may be seasonal) then containment is the best way to go until the compost is done.

        A problem with plumbing code, is extremely high cost of infrastructure (kind of a fits-all solution, that doesn’t fit all). A code compliant greywater system for a single kitchen sink (still not adopted from Uniform Plumbing Code where I live, but possible in other places) would cost me $6000 or more to install!

        This is why people are trying these things themselves. It becomes necessity in this economy to have some alternates to the ‘norm’.

  9. This is a good toilet for tea drinkers! I use a sawdust bucket toilet and yes, urine does get a bit out of control sometimes (no tea parties allowed?!?!) This should cut down a bit on the sawdust use and allow longer times between emptying the container.

  10. George Washington had drawers under the holes in his outhouses (called “necessaries”). When the drawers got full, they were emptied into the compost pile for the flower gardens. I think he used animal waste to fertilize his kitchen gardens.
    I don’t know if he used sawdust to keep down the smell. He was a pretty inventive guy, so he might have.

    Interesting post.

  11. The people that use this design really like it. It is the result of reading hundreds of articles, and building several prototypes in our workshop. I have been designing and building green products for forty years, and marketed many of them successfully. There is a sound reason for every aspect of this design. Change it if you like, but don’t blame me if you get negative results. The unit is designed to be comfortable so it is larger than others. The urine bin is quite deep but has a drain in it so it never fills up. Obviously it is up to the user to direct the urine elsewhere. Evidently someone missed that feature. A long bin is used because it’s was not practical to put a sliding adjustable urine separator in a five gallon pail. The unit has a vent stack so I doubt that a little spritz with diluted bleach and water is going to hurt anyone and is very effective in killing any odors that tend to build up in in urine collectors. I wrote this article because several hundred people asked me to in the past months. We would all welcome a better idea if someone will submit an article I’m sure Kent would print it.

    • Excellent… seems close to a homemade version of the Nature’s Head, which is almost $1000.

      For those who don’t want to separate urine and solids… well, don’t then.

      Those who don’t want to bleach the urine collector… don’t.

      However, I am still living in a normal house with a flush toilet connected to a septic tank, and I clean my bathroom with bleach in spite of knowing the bacteria in the septic are necessary for the system to work. I mean, it’s a bathroom! The septic was pumped out once a year after we moved here, and the tank has functioned fine for another 8 years in spite of my bleach usage.

      The advantage to separating is that you don’t HAVE to compost urine. Thus the urine collector can be dumped every day or two, and the dry solid matter only needs to be dumped every month or so.

      There’s many applications where that’s useful. In an RV or boat, where you have occasional access to rest areas, the urine collector can be dumped without worry about the solids (assuming you don’t drive or boat for more than a month or so).

      You might not HAVE anywhere to compost if you don’t own land. You can’t just go dump your contents on a city park, ya know. It’s not safe until AFTER it’s been composted. If disposing of the urine separately, the solids can be disposed of in a simple kitchen trash can if need be and taken to an appropriate disposal location. Much simpler to do that every month or two than a few times a week.

      BTW, diabetics can sometimes produce over a gallon of urine a day. I really don’t see a 5-gallon bucket being real useful in that case; you’d need a LOT of sawdust and daily removal. And there’d not be enough nitrogen to compost the sawdust as the urine produced is extremely dilute… with regards to nitrogen, and much higher in carbon due to sugar spillage.

      In short, there’s all sorts of reasons to do it this way, really depends on your application.

  12. I’ve often thought how wasteful it is to flush our waste away rather than recycle the nutrients and save the cost of sewer systems and treatment. But, I don’t see the average American hauling buckets of fecal matter around and dumping them on steaming compost piles. There must be reasonable hands-off or less labor-intensive alternatives.

    • There are less labour-intensive options, they’re just extremely expensive. There are whole-house multi-unit composting toilet systems with large collectors that take several years worth of humanure before they need to be emptied but have only a regular toilet sized unit in the actual bathroom. They’ve been used all around the world for many years. Walt’s design is simple, affordable, makes it possible to get your tiny house up and running without putting out big bucks for a toilet but still have an ecologically sound option all while also solving one of the problems of small compost toilets.

    • Instead of a compost pile, you can just put it in a 55 gallon barrel with a net for air and a lid. When it is done you can sell your compost on craigslist or give it to a friend. Hey friends wants some year old poop that smells really good?

  13. Thanks Walt for putting together such a great article on composting toilets. I must say, I feel as if one point you made overlooked the realities of life and I would like to suggest a revision.
    “In third world counties people can be very careless about where they dispose of their fecal matter.”

    Folks who live without organized sanitation (including normal toilets or composting toilets) generally do so because of extreme poverty. I’m sure you know this. To characterize the presence of fecal matter in their drinking water as simply an issue of carelessness is inaccurate, to speak mildly. Even if they wanted to, they don’t have access to sewage systems. They don’t have claims on land where they can bury their waste, separate from the rest of their lives. There’s an extremely fascinating book called “Slum Ecology” – I recommend it highly. It characterizes, in one chapter, the supreme challenges of finding somewhere to defecate. Fascinating and humbling. We are so lucky that we can even contemplate where we might compost our poo, much less how.

  14. Walt .. from the photo’s, it looks as though there is no “breathing” to your compost basin. How do you address odor abatement? With no breathing to the outside, how do you eliminate the unavoidable smell? (Don’t get me wrong, I’m not trying to sound negative either.)

    • Rando, Walt may not have stated specifically, but it’s the saw dust (other organic products will work as well, mulch, crushed leaves, shredded paper ect.,) that absorbs odors completely. I’ve been trying out the composting principles in a plastic port-a-potty that usually uses water and chemicals. I started using it in the spring and the 3 gallon bucket is nearly full after using on a weekend basis (just myself) every two weeks. I also place the cover on when I’m not it’s not in use or I’m away. There is NO SMELL, only some water condensation on the lid.
      I have also had my two cats on organic, saw dust based litter since January. That was the last time I had any noxious ammonia cat urine smell in my house. I store the used litter in a old plastic cat litter pal and take it up to my compost pile at my country place, where I will also deposit my own waste. Following the Humanure principles, it keeps all the compost contained and odor free. I just balance the pile by adding green scraps (kitchen veggies scraps and garden weeds and grass) because wood products break down at a slower rate.

      • Thanks James! Probably showing my ignorance here but I had been led to believe all composting toilets had to “breathe.” Thanks for the clarification. I always learn so much from all of you folks on here!

  15. Thanks Walt! Even if I might want to do things a bit differently for my own situation, I greatly appreciate your time, effort and willingness to share!

  16. Suggestion: Glue small squares of scrap wood to inside bottom corners of cover to keep it aligned instead of the unsightly exterior aluminum tabs.

  17. Walt, thank you so much for this “perfect timing” article. I have been studying composting toilets for the past forty years and am happy to find a plan that will work very well for me. I showed this to my husband this morning and he actually got excited about your plan and is going to start building one for our master bathroom this weekend! Bless you! Our raised septic field lines are failing and we cannot afford to have them re-done on our lowly retirement so the time has finally come to make a composting toilet…and yours is the one we will build! We live on a ten acre homestead in southern AL and raise a lot of redworms so this will work out well with our other composting ventures here. I already have them compost our bunny poo! Thanks again!

  18. this is great Ive been slowly building a 140 sq ft tiny house on a trailer for a few months and I’m getting to a point were I need to pick a toilet and this is looking good thanks. I like the idea of separating the urine and I thinking of putting a urine house through the floor and out to a small tank. I’m wondering what should be done with the urine should it be added to the compost or can it be dumped separate?

  19. Thank you for putting this together, Walt. As someone who’s hauled some of those full 5-gallon buckets – separating the pee makes any composting toilet lighter and less stinky. This one looks affordable and usable.

  20. We had a very busy weekend here and I just now have had the time to read the rest of the comments, and there are plenty of good ideas in them. There are also a couple of comments that indicate the person did not read the article very carefully, or misunderstood. Over all, I think it was a good experience for all of us. There is a vent stack in this unit and it can be used with or without a solar powered exhaust fan. Most of the state parks that I have visited have solar powered vent fans, and many also have solar hot water heaters.
    I mentioned the disposal of fecal matter but evidently some people missed that. I assumed the mention of composting and keeping the compost away from runoff would cover it. There are many ideas, and articles on the Internet regarding the various methods of composing fecal matter and urine. I like using earthworms in the composting process.
    I want to thank everyone for commenting. It makes the effort worth while.
    I have submitted an article to Kent last night explaining the care and maintenance of solar and other lead acid batteries. One of my companies is a battery company that I started over 25 years ago. You will learn how to extend your battery life by taking better care of your batteries.
    I have also filmed our 20′ x 24′ Micro Home that is now two full levels and part of a larger home by necessity, but started out in 1929 as one level with a sleeping loft. We renovated it ten years ago. It is now a super insulated green home with passive solar. It is a good example of what can be done. If it was just the two of us we would still be living in it but we were forced to enlarge the home due to family and business concerns. I hope you will enjoy the film and the article that will accompany it. I will submit that article this afternoon.
    Thanks to everyone for reading and commenting.

  21. I forgot to mention in my previous post..the key to a good workable design is that the seat should not be set too far back from the front of the box. My two girls (11 and 10) have short legs and the seat needs to be near the front of the containment box….if you think about a normal toilet the front of the seat is right there…not set back. I’m about 6 feet so it might not be as much of a concern for me…but smaller people will have the front of the box hitting the backs of their legs…Just because you are saving water and other resources doesn’t mean you need to sacrifice comfort.

  22. I’ve used a humanure-style composting toilet for about a year. I don’t think I would want to use the system described in this post. The key to the humanure toilet is using lots of cover material in the toilet. The round, five-gallon bucket is the perfect size; after using it, you can add enough sawdust (or peat moss) to cover without having to fill in too much around the edges. Also, five-gallon buckets are made for food services and are not porous. This prevents the build-up of odors over time. It also means you only have to use a small amount of water to clean it, and you can dump the water directly into the compost bin. I don’t think that’s true of the plastic storage container being used for this other system.

  23. An other idea to help keep the urine bin as empty as possible would be to use a cut away inverted container with a screw cap facing down, if you can find one large enough. This would eliminate the raised interior edge of the drain fitting. Or perhaps using an angled port-a-potty style catch bin. Perhaps using a light vinegar solution instead of bleach will work for sanitation and oder if it does not increase the acidity too much.

  24. This is awesome, thank you: easy how-to instructions

    I was just going to put a toilet seat on top of one of those 5 gallon pails, fill it with cat litter, then scoop solid waste into the trash; hey, it’s what I have to do for 3 cats, one person is not much harder

    Your way is better, completely biodegradable instead of living for decades in a plastic bag at the landfill, and returns solid waste back to nourish the earth (like livestock pies do)

  25. I have a 5 gallon bucket composting system in my cabin. I use sawdust or bagged compost. I do not have an odor problem, and do not mind removing the 5 gallon bucket. I made a large compost bin out of concrete blocks, where I “mature the compost.” When it is full, I will make another one to the side and let it mature fully. I have several buckets and prefer to transfer out immediately rather than clean the bucket and return. After a couple months, I became amazed that we shifted to water toilets and flushing our feces into our drinking water system. Ugh.

  26. I’ve been using the bucket method for over 6 months with no odors, no fuss.
    I find it interesting that someone commented how they appreciated ‘your attempt’ to solve the problem. Actually this is not an attempt, it IS a solution. There will always be people who try to make it more complicated that it needs to be. As they say, ‘Compost happens’. No need not pretend we are better than nature.
    Another source for composting toilet design is here:
    In Christchurch,NZ with earthquake after earthquake knocking out the sewage and water, composting toilets in the city has become a matter of necessity, not experimentation.


  27. Why not an old fashion out house? I grew ou with them and we had no troubles with them…a little odor every great now and then but sawdust would take care of that.
    Also, if I made this example, I would make one end fold down so I could slide the container out instead of having to lift it out. Much easier.Love your site and info,

    • Kathy, I think the idea is to save the ‘stuff’ and use it as compost. And I like your idea of the drop-side for container removal-sounds easier!
      The question I have is…what do I do with the toilet paper? Will it go in and compost along with the poo or do I have to separate that out?

      • Hi there! Toilet paper will break down just fine, so you can add it to your composting toilet or humanure toilet. Paper products are basically the same as leaves or wood – that’s how I think of it!

        The problem with an open pit outhouse is that the “juices” can leach or leak down into the ground and come into contact with groundwater. This is a potential health and environmental threat.

        Composting toilets are kept isolated from the ground, and any compost piles with human waste should ideally be covered to control the moisture and therefore leaching. A simple lid to a large 3-bin system will ensure no leaching. You can then just add small amounts of moisture yourself, if/when needed.

  28. I have to say that I think these toilets are sorely needed in rural Alaska, where people often are stuck using honeybuckets (or where there isn’t too much permafrost, outhouses) in the winter because of frozen pipes or lack of plumbing entirely.

    If you don’t know what a honeybucket is, count your blessings! 🙂

  29. Thank you, Walt for taking the hours to create and post this WELL THOUGHT OUT design! It is a shame that people are so free to give their negative opinion rather than appreciate your effort at no cost to them.

  30. Some additional thoughts:

    Consider cutting the bottom out of an oblong shaped plastic container such as used for laundry detergent installed in the box for use as a female urinal with a hose to the drain instead of the tub with a drain hose. Provide a second one made from an inverted 1 gallon bleach bottle adjacent to the box on a wall (or other convenient place) for the boys to use that is piped to the same drain. (It would be better than having urine on the top of the seat!)

    Consider using a “cut-down, modified” 5 gallon plastic bucket that would be tall enough to fit to within 1” of the underside of the box, under the seat to catch diarrhea spatters. In addition the handle could be relocated on the sides where it would not get soiled and be swung out of the way while being filled. The front could also be modified to accommodate the inverted female urinal.” The height of the “new” plastic bucket would allow for ventilation to the exterior vent pipe.

    Consider providing 3 or 4 – 1 inch holes in the front of the box near the bottom for intake air for the ventilation system. Attach screen on the inside of the box over the holes. Since warmer air in room is at the ceiling, the top of the ventilation pipe would be warm enough to ventilate the box without an exterior fan, most of the time, by convection.

    Consider adding a rotating cap on the top of the vent pipe that would follow the direction of wind flow away from the pipe. As the wind moves over it, the venturi effect would pull the air up the pipe and ventilate the box.

  31. For those who don’t like bleach, we use a spray bottle with a few drops of tea tree oil added to water for our urine diverting Nature’s Head composting toilet. It leaves a fresh smell and a nice, clean bowl. 🙂

  32. Good job on the DIY toilet. You might consider adding a fan and vent to the outside. There is moist, stinky air in that toilet, and that belongs outside. It’s a small and inexpensive modification, and you can see it on the DIY page on my site. For a fairly small cash outlay, you can get a urine diverting seat, which I think would work better for you as well. Some people have commented here on the Humanure Handbook. It’s a good read, but out of date. They recommend adding a large amount of organic material to the toilet, after every use. Ugh. You have to store that inside the house, with a risk of insects. It reduces the toilet’s capacity. And Humanure toilets usually do not have fans with vents. We’ve come a long way since then.
    I do have a new post on the top 10 questions I get on composting toilets. You can read that here:


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