Pin Me

Cost and Efficiency Comparison of Composting Toilets

written by: Sage Kalmus•edited by: BStone•updated: 5/23/2011

Finding it difficult to understand or compare composting toilets? With so many variations available, it can be hard to find the most practical waterless toilet for your home. Understanding the differences between the features increases your ability to make an informed decision.

  • slide 1 of 6

    Human waste is an inevitable part of any discussion on green living. Composting toilets, available from companies such as Sun-Mar or Envirolet, are a product that offers consumers the flexibility to compost their own waste in order to decrease their environmental impact. The following will help you to compare composting toilets in terms of function as well as cost.

  • slide 2 of 6

    Self-Contained Composting Toilet

    The self-contained composting toilet is exactly what it sounds like. The toilet is combined with the compost reactor, creating a single unit in the bathroom space. They are easier to install than some of the other composting toilets on the market.

    Since the toilet bowl and the compost reactor are combined however, self-contained models offer limited waste space. They are best used in smaller home situations or seasonal homes where they are only used part of the year. These toilets make use of an exhaust system to remove the odor and heat caused by decomposition.

  • slide 3 of 6

    Central Composting Toilet

    Central composting toilets are also sometimes called remote units. In this case, the compost reactor is housed in another area of the home (likely the basement or even outdoors) but is connected to the toilet in the bathroom.

    Some consumers appreciate that this allows for a “normal” looking toilet in the bathroom rather than the bulky self-contained unit. This also separates the process of composting from the actual toilet, allowing for increased storage, decreased occurrence of odor, and year round use. However, having a separate toilet and compost reactor raises the cost of installation and maintenance. These systems use a similar exhaust system to the self-contained composting toilet but often require electricity to keep them at a constant temperature for composting purposes.

  • slide 4 of 6

    Other Features That Cause Price to Vary

    Composting toilets can come with a variety of add-ons that can change the price and efficiency of the unit. Anytime you add a feature, it drives the price up but can also increase the efficiency of the model. Both self-contained and central composting toilets can use electricity or not. While a non-electric, self-contained unit can cost around $1,300, the electric version can cost several hundred dollars more. The electricity can be used to feed a fan exhaust system or heat the compost reactor in order to speed the rate of decomposition.

    Central composting toilets can range from gravity fed to vacuum flush. The gravity fed model requires the central unit to be located directly below the toilet whereas the vacuum flush models can be placed further away and, in some cases, around corners. The vacuum flush model can be more expensive, but allow for more flexibility in placement and efficiency in movement of waste to the compost reactor.

    Central composting models can also vary between having one large composter reactor versus several smaller units. The benefit of the smaller units is that the compost has time to cure without the constant addition of free waste. This can speed up the decomposition process but requires more monitoring as the bins fill up quickly.

  • slide 5 of 6

    The Economic and Environmental Value

    The economic value of these eco-friendly toilets is quite large. While a composting toilet can cost between $1,000-$3,000 dollars before installation, there is a large savings over time when it comes to sewage, water, and maintenance costs. With one of these eco-friendly toilets, there is no need to pay for a costly septic system if you are living somewhere without a city maintained water system.

    The green value is, overall, the greatest positive attribute of the composting toilet because it eliminates extreme water usage on human waste as well as water treatment chemicals and toilet cleaners from the environment. There is also a community savings in the decreased need for water treatment or concern for water scarcity. Additional benefits come in the form of the compost that is created. If composted correctly, human manure can be safely used as a fertilizer.

    Overall, the composting toilet is a fairly customizable green consumer choice. Compare composting toilets to find the ideal model for your home. By buying a unit that is appropriate for your needs, you can help to decrease your environmental impact and save money while doing it!

  • slide 6 of 6


    "3 Types Of Composting Toilets." Let's Go Green. Web. 12 June 2010. <>.

    "Composting Toilet Systems - Oikos." Green Building - Oikos. Oikos. Web. 12 June 2010. <>.

    Edmonds, Molly. "How green is a self-contained composting toilet?." 07 July 2008. <> 12 June 2010.

    "FAQ." Composting Toilet World. Envirolet, 2010. Web. 12 June 2010. <>.

    Fisher, Adam. "Humanure: Goodbye, Toilets. Hello, Extreme Composting - TIME." Breaking News, Analysis, Politics, Blogs, News Photos, Video, Tech Reviews - Time Magazine, 4 Dec. 2009. Web. 12 June 2010. <,8599,1945764,00.html>.

    Amazon Search for "Composting Toilet"