How to Build a Self Composting Toilet – Guide and More

More people are becoming environmentally conscious, leading them to make decisions they usually wouldn’t consider. Furthermore, some people choose off-the-grid lifestyles for a more profound sense of privacy while being more in charge of their living situation. Hence, many in this lifestyle state the importance of knowing how to build a self composting toilet.

Using the bathroom is essential, and as straightforward as it may seem, we take how we use the bathroom for granted. It’s no secret how much water is wasted with a standard toilet, not to mention the inability to install a traditional toilet in every setting. Whether you need a toilet for your van, off-the-grid home, or camp, a composting toilet is the option.

Still, not everyone can afford a composting toilet, and building one is easier than most people realize. It’ll probably take some time to get the comfort and design how you want it, but it’s a fun project worth trying. It’ll save you money and give you a deeper appreciation since you’re building it from scratch.

This guide will discuss how to build a composting toilet and the materials and tools required. We’ll review the seven-step process and how you can start today. If you wish to know more, continue reading and explore our guide that highlights what a composting toilet is, why you should consider using one and more.

How to Build a Self Composting Toilet

A composting toilet effectively separates liquids from solids and mixes the solid with an absorbent material such as sawdust. It then turns into compost. Whether you go with a build-your-own option like this or one online, they both follow the same concept. The plan we’re covering is the simplest and most effective variant, made with plywood and a 5-gallon bucket. You’ll also need a toilet seat and urine diverter, which you can find online very cheap.


  • 12mm plywood
  • Four 2×4 planks of wood
  • Screws
  • Wood glue
  • Pocket hole jig
  • Bucket
  • Toilet seat
  • Urine separator
  • Handles
  • Stain


  • Electric drill
  • Handheld jigsaw
  • Screwdriver
  • Drill bits
  • Pocket hole jig
  • Woodworking file
  • Sandpaper

Step One – Build the Box

People don’t realize how important comfort is when using the bathroom. The more comfortable you can make your toilet, the better your experience will be. First, ensure the height is perfect for your size. Understand the taller it is, the easier it’ll be for you to sit and stand up. On the contrary, the more you squat, the easier it is to use the bathroom.

The frame depends on where you’re keeping the toilet, so measure the available space. Also, remember to add the toilet seat size with your dimensions. Begin by cutting six pieces of plywood for the box’s bottom, top, and four sides. Attach these pieces using a pocket hole jig.

Step Two – Cut the Hole

It would help if you made the top of your box reachable so you could access the bucket. Use the toilet seat as a template by placing it on top of the plywood and opening the seat lid. Draw around the entire inside for measurement, and cut the circle wider to give yourself more room.

You can cut the hole by drilling a hole on the line and inserting the jigsaw blade. Your hole probably won’t be perfect, so remember to file it and use the sandpaper afterward to smooth it out. Once you’re done, you can stain or paint it to fit your van, camp, or home better.

Step Three – Add Urine Separator

A urine separator channels urine into a separate container from where the waste will go. It neutralizes the smell, removes urine more efficiently, and keeps the waste bucket drier. Screw the urine separator underneath the plywood lid at the front. There are plenty of urine separators you can find online.

Step Four – Install Toilet Seat

After installing the urine separator, you can place the toilet seat on top of the hole you’ve cut. You can mark the drill holes and use a screwdriver to drill holes for the toilet seat hardware. Ensure the holes are tight enough so the screws don’t get loose and fall around. Take your time with this since the seat is critical.

Step Five – Add Legs

Some people skip this step entirely, but I think it’s worth doing. Technically, the plywood box can rest on the floor, but bathrooms are dirty and can get wet. Plywood doesn’t react well to areas like this, so it’s worth building the legs to give your composting toilet more longevity.

All you have to do is place 2×4 wood at the box’s four corners and screw it together. Once you get it done, place it on the floor and see if it is okay. If the legs are shaking or it’s not even, you’ll have to check the screws and adjust. It might take some time, but once you nail it, it’s worth it.

Step Six – Get Buckets

You’ll need two buckets for your composting toilet. One bucket is for fecal matter, while the other is for urine. Your urine bucket should preferably be long and narrow. Usually, a 3.5-liter plastic pot is enough for a day. As for the waste bucket, a 5-gallon plastic bucket works well. Always ensure you have at least three buckets in case two are complete.

Step Seven – Add Absorbents

Once everything else is copacetic and installed correctly, all you have to do now is add absorbents. You can use dried leaves, sawdust, wood ash, or anything that works as an absorbent. Absorbents are used to neutralize foul odors and soak up excess moisture.

Give it a Try!

Now that the hard work is done, you’ll want to see if the toilet is how you want it. It may work out well right away, or you’ll have to go back and see if any adjustments are needed. Whatever the case, check for local laws and guides to see how you can dispose of the waste or use the compost where you live.

Now that you fully understand the process of how to build a self composting toilet, let’s discuss some related information worth reviewing.

What is a Composting Toilet?

A composting toilet serves the same purpose as a traditional toilet, but rather than flushing away waste, it collects it and turns it into compost. It’s a way of turning something we’d normally throw away into a resource. Don’t confuse a composting toilet with an outhouse. If you build it right, it won’t have the same odor you’d tie to an outhouse.

Since composting toilets don’t require plumbing, you can build them anywhere. It also doesn’t add to pollution, a more significant issue than most people realize with traditional toilets. In its simplest form, a composting toilet combines human fecal material with dry materials such as sawdust, wood ash, or crushed leaves.

You dump these dry materials, also known as absorbents, into your composting toilet, and the natural process does the rest. Some people use compost for their gardens, including fruit trees and vegetables. Others dispose of the compost safely, which local laws help determine.

Different Types

If you didn’t know, there are two primary types of composting toilets. A self contained composting toilet is when the compost system is enclosed within the toilet and under the bowl. These toilets are ideal for vans, buses, RVs, boats, and tiny homes. You may also find them in cabins and cottages, and you can make one independently (as discussed).

A central or remote composting toilet takes your waste to a central unit that’s not beneath the bowl. Most of the time, this location is in the basement or outside. You can channel a few of these in your home if you have a sizeable remote system. Though more challenging to install, it feels closer to a traditional toilet.

Why Consider Using One?

Greener Alternative and Conserves Water

Most people turn to a composting toilet for its environmental benefit over a traditional toilet. Though it’s more versatile than a traditional toilet, the water conservation and benefit for the planet are undeniable. For example, septic tanks are expensive and impossible in many areas.

Environmental regulations may also prohibit you from setting up a septic tank. In contrast, a composting toilet lets you deal with your bowel movements in the healthiest way possible. It turns your waste into food for plants; how great is that? Furthermore, it doesn’t waste water, and considering how many areas struggle with water scarcity, any bit helps.

No Plumbing Required

If you’re interested in a composting toilet, it’s probably because you plan to use one where plumbing isn’t an option. Whether it’s a van, bus, RV, tiny home, or outdoor cabin, there are plenty of areas where plumbing isn’t available. Unfortunately, we still need to go to the bathroom, no matter where we are.

A composting toilet is a perfect solution for these settings, where plumbing is non-existent or inefficient. Going back to the environmental impact, a composting unit is less impactful than tearing out the ground to install pipes. Many choose a composting toilet for older builds to avoid that issue entirely.


Living off the grid is not only about being environmentally conscious but also about saving money. Not only will you save money from a plumbing perspective, but composting toilets are much more affordable than traditional toilets. For example, with the option we covered earlier, you could build for under $20.

Composting toilet issues won’t cost you as much as a traditional toilet. For example, if you have a plumbing issue, that can cost you thousands of dollars. Not to mention how much it can hinder the land or people around you. With a composting toilet, it’s singular, meaning it won’t affect those around you and is easily fixable when an issue pops up.

Odorless Option

Whenever someone looks into a composting toilet, their biggest fear revolves around the smell of one. As strange as that might be, it makes sense considering how sensitive we are to smells. As long as you build and install the composting toilet correctly, you won’t experience any foul smells.

You can order many composting toilets online with further steps than we covered, such as a fan to keep moisture from building up. Regardless, the biggest reason odors are mitigated how urine and waste are separated. Most of the time, odors occur when our liquids and waste mix.


Can You Make a Composting Toilet?

Yes, you can make a composting toilet on your own, as we talked about earlier. What makes it so appealing is the ability to craft a toilet to your preference. Buying a composting toilet online means you’ll have to risk the toilet not fitting your size or comfort requirements.

A composting toilet is enough to build, where you’ll only need a few essential tools. You’ll need a few sheets of plywood, a toilet seat, screws, and a bucket with absorbent material. Some people make simpler units using a medical toilet seat. Whatever the case might be, have fun with it!

How Do You Make a Composting Toilet Not Smell?

The most significant way to ensure your composting toilet doesn’t smell is to prevent moisture from developing. As great as a urine diverter is for this purpose, you must also ensure enough absorbents are in the bucket. Always keep enough hardwood sawdust, peat moss, dry leaves, or coconut coir.

Some people install small computer vans to help vent any lingering odors. Many pre-made composting toilets have a vent fan in the unit, but if you’re building it on your own, you’ll need to acquire a separate one. Ensure it’s small enough to install and can run on batteries when you don’t have power.

What are the Drawbacks of Composting Toilets?

As great as composting toilets are, it may take some time to get used to, especially if you’re transitioning from using a traditional toilet. Though the act is the same, a composting toilet needs much more maintenance. The positives outweigh the negatives, but it’s worth noting.

For example, you must manually empty a composting toilet, whereas you don’t with a traditional toilet. You also might have to tinker with the unit for better comfort and to eliminate odors. However, as you get used to using a composting toilet, those maintenance requirements will get easier and not seem as big of a deal.

Are Composting Toilets Expensive?

Like anything else, the price of a composting toilet varies depending on the option. There are cheap DIY options like the one we covered, which won’t cost you more than $20. On the contrary, you can buy high-quality composting toilets online for thousands of dollars.

They all share the same function of being versatile composting toilets. If you have the money, the higher-end options are comfier, easier to install, and have many options you can’t build your own. Still, only consider going that route if you have the budget.

Are Composting Toilets Popular?

Yes, composting toilets are popular. With van life and off-the-gride lifestyles growing in popularity, many people are composting toilets to fulfill their bathroom requirements. Not only is it from a budget or environmentally friendly perspective, but also for how versatile these toilets are. No matter where you are, a composting toilet is possible anywhere.

Do You Need Electricity Composting Toilets?

Some composting toilets may require electricity for their vent fans. Usually, these toilets have a battery-powered option if you can’t use power from a vehicle or home. However, there are plenty of options where no electricity is required. If you don’t want electricity involved, then be aware of that while surveying your options.

Can You Urinate in Composting Toilets?

Yes, you can urinate in these toilets. It’s why so many people use urine diverters with their composting toilets. Most composting toilets have urine separated from the waste, and an exhaust fan evaporates any moisture that hits the waste. It helps reduce the moisture in the toilet, making it less likely for smells to develop. You can also dispose of toilet paper in your composting toilet, but be mindful of how much you use.

There’s an odd stigma with disposing of toilet paper in a composting toilet. Although some units are better than others, you don’t have to worry about your toilet getting clogged or ruined. The thinner the toilet paper, the better since that’ll be easier to break down. Many companies make toilet paper, for this reason, so search for eco-friendly toilet paper.

Final Thoughts

There’s no better feeling than finishing a project like a composting toilet. Considering you’re investing so much time into where you live or your mobile or camping setting, why not build the toilet too? It’ll save you money, and you can be specific about its size and features, which is a huge plus.

Understanding how to build a self composting toilet is helpful to know, especially for a mobile or camping setting. It grants you access to use the bathroom when you need to rather than relying on a rest stop every time you need to. If you don’t want to build your own, plenty of reliable composting toilets are worth buying.