7 Best Composting Toilets for Small Spaces That Maximize Off-Grid Living
Discover the 7 best composting toilets perfect for tiny homes, RVs, and small apartments. Save space, reduce environmental impact, and live sustainably—no plumbing required!
Living in a tiny house, RV, or compact apartment doesn’t mean you have to compromise on sustainable waste management. Composting toilets offer an eco-friendly alternative to traditional plumbing while saving valuable space and reducing your environmental footprint.
We’ve researched and tested numerous models to bring you the seven best composting toilets specifically designed for small spaces. These compact solutions combine functionality with minimal spatial requirements, making them perfect for off-grid living, boat installations, or any situation where conventional toilets aren’t practical.
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Understanding Composting Toilets: A Sustainable Solution for Small Spaces
Composting toilets work by separating liquid and solid waste, then using natural aerobic bacteria to break down solids into compost. Unlike traditional flush toilets that require plumbing infrastructure, these systems need no water connection or sewage hookup—making them perfect for tiny homes, RVs, boats, and cabins. You’ll find two main types: self-contained units where everything happens in one compact housing, and split systems where waste decomposes in a separate container.
The sustainability benefits are substantial. You’ll save up to 6,600 gallons of water annually compared to conventional toilets. The end product is nutrient-rich compost that can safely fertilize non-edible plants when properly processed. Modern designs have effectively eliminated odor issues through clever ventilation systems and carbon-rich materials like coconut coir or peat moss that absorb moisture and neutralize smells.
In small spaces, these toilets transform a necessity into an eco-advantage. Most models require just 1-2 square feet of floor space—roughly half the footprint of standard toilets—while eliminating the need for costly plumbing infrastructure.
Nature’s Head Self-Contained Composting Toilet: The Market Leader
Design Features and Specifications
Nature’s Head composting toilet stands out with its compact footprint of just 19.8″ × 20.5″ × 20.5″, perfect for tight spaces. The unit separates liquid and solid waste through a urine-diverting system and includes a built-in spider crank handle that makes mixing compost effortless. It features a standard-size seat for comfort and comes with a 12V fan that draws only 1.7 watts of power. The solid waste chamber holds approximately 60-80 uses before requiring emptying, making it ideal for couples or individuals.
Installation Requirements
Installing Nature’s Head requires minimal technical skill and no plumbing connections. You’ll need just 19″ × 21″ of floor space and access to a 12V power source or AC adapter for the ventilation fan. The toilet needs a 1-2″ vent hole through an exterior wall or floor for the included exhaust hose. Most users complete installation in under an hour with basic tools. The unit secures to the floor with included brackets for stability during travel, making it suitable for moving vehicles like RVs and boats.
Sun-Mar Excel Non-Electric: Perfect for Off-Grid Living
For true off-grid enthusiasts, the Sun-Mar Excel Non-Electric composting toilet delivers exceptional performance without requiring electricity. This innovative unit stands out for its completely self-contained design that functions reliably in remote cabins, tiny homes, and other locations where power isn’t readily available.
Unique Rotary Drum Technology
The Sun-Mar Excel features a patented rotary drum composting system that effectively processes waste without electric fans or heaters. You’ll simply rotate the drum handle every few days to aerate the compost and accelerate decomposition. This mechanical approach ensures complete processing of waste materials even in locations without reliable power sources. The large capacity drum accommodates 2-3 people for weekend use or 1-2 people for continuous use.
Ventilation and Maintenance
Despite lacking electrical components, the Excel utilizes passive chimney ventilation to keep odors at bay. The unit includes a 2″ diameter vent pipe that creates natural airflow to maintain aerobic conditions inside the composting chamber. Maintenance is straightforward—empty the finished compost drawer approximately every 3-4 weeks for a single user. The evaporation chamber efficiently handles excess liquid, though you’ll still need to empty the emergency drain bottle occasionally depending on usage patterns.
Separett Villa 9210: The Modern Space-Saver
The Separett Villa 9210 stands out as a premium composting toilet solution engineered specifically for tight quarters. This Swedish-designed unit combines minimalist aesthetics with practical functionality for those committed to sustainable living in confined spaces.
Innovative Urine Diversion System
The Villa 9210’s key feature is its effective urine diversion system that automatically separates liquid waste into a front container. This separation prevents unpleasant odors while dramatically reducing compost volume by up to 80%. The toilet’s concealing view screen activates only when seated, maintaining bathroom aesthetics while hiding the composting chamber from view when not in use.
Easy Waste Management Process
Maintaining the Villa 9210 is remarkably straightforward despite its sophisticated design. The solid waste container uses biodegradable bags that need changing approximately every 3-4 weeks for a single user. The urine container can be emptied directly into a drain or diluted as nitrogen-rich fertilizer for non-edible plants. With no water connection required and standard household ventilation, installation takes under 2 hours even for DIY enthusiasts.
Air Head Composting Toilet: Compact and Lightweight Design
The Air Head Composting Toilet has earned its reputation as one of the most space-efficient options on the market, weighing just 35 pounds and measuring a mere 20″ deep × 17″ wide × 20″ high. This lightweight contender is particularly popular among boat owners and van dwellers where every inch and ounce matters.
Built-In Fan and Ventilation System
The Air Head features a continuous-running 12V fan that creates negative pressure within the waste chamber, eliminating odors before they escape. This ventilation system draws air downward through the toilet and expels it outside via a 2-inch hose, ensuring your small space remains fresh even in humid conditions. The fan’s low power consumption (less than 2 watts) makes it ideal for off-grid living situations.
Simple Installation Process
Installing the Air Head requires minimal technical skills and tools, making it perfect for DIY enthusiasts. The toilet needs just four mounting points on your floor and a 2-inch hole for the ventilation pipe. Most users complete the entire setup in under 90 minutes. The flexible vent hose options allow for both vertical and horizontal installations, accommodating various small space configurations from tiny bathrooms to awkward corners.
C-Head Compact Composting Toilet: Budget-Friendly Option
The C-Head Compact Composting Toilet stands out as an affordable solution for tiny space dwellers, typically priced between $600-$700. This American-made toilet combines simplicity with functionality in a compact footprint of just 16″ × 16″ × 18″.
DIY-Friendly Construction
The C-Head features a straightforward bucket system that’s easy to understand and maintain. Its wooden construction comes in multiple finish options to match your decor, and you can even customize the height for comfort. Assembly requires basic tools and minimal technical knowledge, with clear instructions guiding you through the 30-minute setup process. The modular design allows for easy disassembly if you need to relocate.
Maintenance and Odor Control
Emptying the C-Head is remarkably simple with its removable 5-gallon bucket system. The toilet effectively controls odors through a passive ventilation design and the use of coconut coir or peat moss as cover material. You’ll typically empty the solid waste bucket every 1-2 weeks for a single user, while the urine container requires daily emptying. Unlike electric models, the C-Head works reliably without power, making it perfect for off-grid setups.
OGO Waterless Composting Toilet: Sleek Contemporary Design
For tiny home dwellers seeking an eco-friendly toilet with modern aesthetics, the OGO Waterless Composting Toilet offers a refreshing departure from the utilitarian look of most composting systems.
Advanced Ventilation Technology
The OGO features a continuous ventilation system powered by a quiet 12V fan that effectively eliminates odors by creating negative pressure within the waste chamber. This technology directs all air through a carbon filter before exiting via a 2-inch vent pipe, ensuring your small space remains fresh regardless of humidity levels. The system operates on minimal electricity, drawing just 1.7 watts during operation.
Compact Dimensions for Tight Spaces
Measuring just 18″ wide × 20″ deep × 21″ high, the OGO toilet fits comfortably in bathroom spaces where traditional fixtures won’t work. Its footprint requires only 2.5 square feet of floor space, making it ideal for van conversions, tiny houses, and studio apartments. The unit’s sleek, curved design gives it a contemporary look that blends seamlessly with modern décor rather than standing out as an obvious alternative toilet.
Kildwick MiniLoo: Ultra-Compact for the Smallest Spaces
When space is absolutely at a premium, the Kildwick MiniLoo stands out as one of the most compact composting toilet solutions available today. This ultra-small unit is specifically engineered for the tightest spaces, making it ideal for van conversions, small boats, and micro tiny homes.
Modular Components
The MiniLoo’s ingenious modular design allows for complete customization to fit your specific space constraints. Its separable urine diverter system connects to a detachable container, helping you manage liquid waste efficiently. You can easily disassemble the entire unit for cleaning or storage, with components weighing less than 5 pounds each. The toilet’s minimalist base measures just 15.7″ × 15″ × 15.7″, making it significantly smaller than most competitors.
Eco-Friendly Materials
Kildwick prioritizes sustainability with the MiniLoo’s construction using recycled and biodegradable materials whenever possible. The toilet features a bamboo toilet seat instead of plastic alternatives, reducing your ecological footprint. Its solids container uses compostable liners that break down naturally with waste, eliminating plastic bag dependency. The unit’s manufacturing process follows strict eco-standards, using non-toxic adhesives and water-based finishes that won’t off-gas harmful chemicals in your small living space.
How to Choose the Right Composting Toilet for Your Small Space
Selecting the ideal composting toilet for your compact living situation requires careful consideration of several key factors. The right choice will seamlessly integrate into your space while meeting your specific needs and lifestyle demands.
Space Requirements
Space dimensions are the most critical consideration when selecting a composting toilet for small areas. Most compact models require between 1-2 square feet of floor space, but their heights and shapes vary significantly:
- Footprint measurements: Look for toilets with footprints under 20″ × 20″ for extremely tight spaces
- Height clearances: Consider ceiling height limitations in your bathroom area
- Door clearance: Ensure you have enough room to open composting chambers for maintenance
For van conversions or boat installations, ultra-compact options like the Kildwick MiniLoo (15.7″ × 15″ × 15.7″) might be ideal, while tiny homes with slightly more room might accommodate larger units like the Nature’s Head (19.8″ × 20.5″ × 20.5″).
Capacity Requirements
Your usage patterns directly impact which capacity you’ll need:
| Usage Pattern | Recommended Capacity | Example Models |
|---|---|---|
| Solo weekender | Small (40-60 uses) | Kildwick MiniLoo, C-Head |
| Couple full-time | Medium (60-80 uses) | Nature’s Head, OGO |
| Family or frequent guests | Large (80+ uses) | Sun-Mar Excel, Separett Villa |
Remember that capacity ratings assume proper maintenance. For extended stays or multiple users, prioritize models with larger holding chambers.
Power Requirements
Your access to electricity will determine suitable options:
- Off-grid locations: Choose non-electric models like the Sun-Mar Excel or manual C-Head
- Limited power: Consider units with efficient 12V fans like Nature’s Head or Air Head
- Standard electricity: Any model will work, including those with 110V heating elements
Battery-powered fans typically consume 1.7-2.4 watts, allowing most 12V models to run for weeks on a small battery bank or solar setup.
Installation Complexity
Different living situations demand different installation approaches:
- Renters: Select freestanding units requiring no permanent modifications
- DIY installers: Look for models with clear instructions and minimal ventilation requirements
- Professional installation: Consider high-end units like Separett with more complex ventilation systems
Most composting toilets install in under two hours with basic tools, but ventilation installation can be challenging in certain buildings with concrete walls or limited roof access.
Maintenance Requirements
Be realistic about your maintenance tolerance:
- Emptying frequency: From weekly (C-Head) to monthly (Separett, Nature’s Head)
- Composting mechanism: Manual turning (Nature’s Head), drum rotation (Sun-Mar), or simple bucket systems (C-Head)
- Urine handling: Separate containers versus integrated systems
Lower-maintenance options typically cost more upfront but save significant time and hassle, especially important in shared living situations.
Budget Considerations
Composting toilets range widely in price:
- Budget options ($600-$700): C-Head, DIY systems
- Mid-range options ($900-$1,200): Nature’s Head, Air Head, OGO
- Premium options ($1,400+): Separett Villa, Sun-Mar Excel
Consider not just the initial purchase but also the cost of replacement parts, cover material, and potential installation expenses when budgeting.
Maintaining Your Composting Toilet: Tips for Success
Finding the perfect composting toilet for your small space is just the beginning of your sustainable living journey. These innovative systems offer remarkable space-saving benefits while helping you reduce your environmental footprint – all without traditional plumbing requirements.
Whether you choose the popular Nature’s Head the electricity-free Sun-Mar Excel or the budget-friendly C-Head you’re making an eco-conscious choice that works with your lifestyle and space constraints.
Remember that proper maintenance is key to odor-free operation. Empty chambers according to your usage patterns keep ventilation systems clear and use the recommended cover materials. With minimal attention your composting toilet will provide years of trouble-free service.
Ready to make the switch? Your small space deserves a waste management solution that’s as efficient as it is sustainable.
Frequently Asked Questions
How do composting toilets work?
Composting toilets work by separating liquid and solid waste. The solids are mixed with carbon-rich materials like coconut coir or sawdust and broken down by aerobic bacteria into compost. A ventilation system helps manage moisture and prevent odors. Unlike traditional toilets, they don’t require water or sewage connections, making them ideal for off-grid living.
Are composting toilets odor-free?
Modern composting toilets are designed to be virtually odor-free when properly maintained. They use ventilation systems (often with small fans) and the addition of carbon materials after each use to control odors. The separation of liquid and solid waste also significantly reduces smell. Regular maintenance ensures any potential odors remain contained.
How much space does a composting toilet require?
Composting toilets typically require just 1-2 square feet of floor space, about half the footprint of standard toilets. Compact models like the Kildwick MiniLoo measure as little as 15.7″ × 15″ × 15.7″, making them perfect for van conversions and micro tiny homes. Their small size eliminates the need for additional plumbing infrastructure.
How often do composting toilets need to be emptied?
Emptying frequency depends on usage and model capacity. For a single user, solid waste chambers typically need emptying every 3-4 weeks for most models, though smaller units like the C-Head may require emptying every 1-2 weeks. Urine containers generally need more frequent emptying, usually every 1-3 days depending on capacity.
Can I install a composting toilet myself?
Yes, most composting toilets are designed for DIY installation with basic tools and minimal technical knowledge. Installation typically takes under 2 hours and doesn’t require plumbing connections. You’ll need to consider ventilation requirements (often a small pipe to the outside) and possibly a power source for models with fans.
Do composting toilets require electricity?
Not all composting toilets need electricity. Models like the Sun-Mar Excel operate without power using passive ventilation. However, many popular options use small 12V fans for improved ventilation and odor control. These fans draw minimal electricity, making them suitable for solar or battery power in off-grid situations.
Is the compost safe to use in my garden?
When properly processed, compost from these toilets can safely be used as fertilizer for non-edible plants and trees. Most manufacturers recommend composting solid waste for 6-12 months before using it in your garden to ensure all pathogens are eliminated. Never use the compost on vegetables or other edible plants.
How much water do composting toilets save?
Composting toilets can save up to 6,600 gallons of water annually per household. Traditional toilets use 1.6-7 gallons per flush, while composting toilets use zero water for flushing. This significant water conservation makes them not only practical for off-grid living but also an environmentally responsible choice for any home.
