Planning your tiny house’s plumbing system is easy once you figure out your needs.
So, how do you set up plumbing in a tiny home? We recommend setting up both traditional plumbing (with hookups and sewage drains) and mobile options (portable tanks) for your convenience.
In this article, we break down the truth about plumbing in a traveling home, as well as how to set up an efficient system for the people living in your house.
Read on to learn about the components of a tiny house’s plumbing structure, and how to easily replicate it for your own small abode.
Parts of a Tiny House Plumbing System
If your tiny house is on a foundation, your plumbing will be similar to the ones you find in bigger households, and you don’t have to think about water tanks.
Here are the major components of a tiny house plumbing system:
Water tanks are mobile water and waste storage units. They are commercially available and come in all shapes and sizes.
- Freshwater: The freshwater tank stores the clean water you use for drinking, cleaning, and washing dishes. People fill their freshwater tank by connecting to a water source by hooking up their inlet or by manually refilling the tank.
- Greywater: The greywater tank holds the waste such as water from showering and washing dishes or clothes, excluding human waste. Greywater is easier to get rid of than black water. Although most states mandate that greywater has to be properly disposed of in a facility, homeowners who use biodegradable soaps and shampoos are able to release their greywater without the risk of polluting the environment.
- Blackwater: The black water tank stores human waste. In traditional homes, waste automatically ends up in sewage systems. In tiny houses, waste is stored in black water tanks and disposed of through a service or in an official dumping site. You can view RV-approved dump stations in the US, Canada, and Australia here.
The inlet is where water enters your house to directly feed into your plumbing system or refill your fresh water tank. We’ve heard stories of tiny homeowners having to deal with a broken inlet after connecting to a city supply or an RV camp with strong water pressure. For this, we recommend getting a pressure regulator or control valve for good measure.
Just like in traditional plumbing, waste leaves your home through a proper drain. For homeowners on foundation, there is no need for a water tank since your freshwater and waste will be set up similarly to ones you would find in traditional homes. It would be smart to install one if you’re switching between on-grid and off-grid living so you’re not obligated to dump your black water tank all the time.
If you’re not connected to the city supply, you will need a water pump to make sure water is running through your sink, shower, and everywhere else. Water pumps come in different prices; the more expensive run quieter and more efficiently. Note that water pumps need to be plugged to a power supply to work (typically just 12 V of power).
Just because you’re in a tiny house doesn’t mean you have to let go of basic creature comforts like hot water. Water heaters are becoming a staple in even the smallest of tiny homes. The key is choosing a tankless water heater so you don’t have to think about the extra baggage.
Check out our recommendations on tankless water heaters fit for a tiny home.
Tiny House Plumbing: Which One Works For You?
The next part is figuring out what kind of system is adequate for your tiny home. How your plumbing system is designed is dictated by how you live: will you be living off-grid or will you be living on-grid? How many people will be living in a tiny house? Are you planning to sell your house in the future?
Figuring out your daily routine would be a great way to get started. We would recommend renting a tiny house for a weekend just to see how your needs fit a small space.
On-grid plumbing means you’re connected to a water supply. If you’re in an RV park, you would be connected to their amenities. On-grid plumbing is straightforward; because your supply and waste lines are connected to your parking spot’s amenities (if they have it), you don’t have to worry about disposing of your own waste or fetching your own water supply.
Things to remember:
- You have to purchase a freshwater hose for potable water. We recommend buying one no less than 30 to 50 feet for your convenience. Keep in mind that potable water hoses are not the same as garden hoses; the latter may leak chemicals that could contaminate your water supply.
- Consider getting a detachable water filter to keep bacteria and mineral deposits away from your supply line.
- Don’t run your water pump when connected to city water. City water already has enough pressure to feed your supply line.
- Although RV parks will have sewage systems, prepare your own tubes for easier disposal.
An off-grid plumbing system isn’t connected to any supply lines and uses storage tanks to hold clean water and waste material. More planning is involved with an off-grid plumbing system because you have to think about the capacity of your water storage and wastewater tank.
Things to remember:
- When deciding the capacity of your black water tank, first consider how and how frequently you plan on emptying out your waste tank. National parks, trucks, and RV parks have their own dump stations, but you can also hire someone to offload the waste for you. A one to two-person tiny home typically uses a 10 to 15-gallon black water tank.
- Consider getting a water-free toilet in your tiny house. This eliminates the need to deal with black water completely and simplifies your tiny house plumbing even more.
- Figure out how much water your household consumes on a daily basis. This will help you decide whether you want to use a big or a small freshwater tank. You can use your big tank longer without refilling it. Otherwise, you can get a more space-conscious one that requires more frequent refills.
- Greywater is disposed of in an appropriate dump station. However, if you use biodegradable products, you can dispose of it responsibly without having to visit a dump station.
- You have to purchase a water pump to keep your supply fed with enough water pressure. Because you’re living off the grid, you will also need to have a generator or some sort of power supply to power it up.
If you’re a frequent traveler, a hybrid plumbing system will make the transition from off-grid to on-grid living seamless. With the right system in place, you don’t have to worry about overflows and damages to your home because your tiny house is designed to receive city water and store your own water tank.
Here’s a great model of a hybrid system:
Things to remember:
- Install separate water valves for the freshwater supply and the city water supply. It gives you more control over the water flow and ensures your freshwater supply doesn’t overflow when connected to an RV park’s amenities.
- The model above uses a tank water heater, but you can easily feed your home with hot water by installing a tankless water heater. Although the hot water would be limited to the shower, you won’t have to think about setting up a separate tank for your hot water.
- If you are planning to sell your tiny house in the future, having both on-grid and off-grid options can increase its sale value. It will give the new owners flexibility when deciding what to do with their tiny house plumbing.
Plumbing In a Tiny House: How Much Does It Cost?
Tiny house plumbing isn’t as expensive as plumbing a bigger home. On average, bigger homes within the 1,000 to 2,000 square foot range spend anywhere from $2,000 to $10,000 on plumbing.
The cost of setting up a plumbing system in a tiny house depends on its components. A one to the three-person household with a hybrid system would spend $700 to $900 on materials, not including the toilet and other bathroom fixtures.
To give you an idea, Jenna from Tiny House Giant Journey invested $700 for her tiny house plumbing system. Her set-up looks like this:
Waterless Tiny House Toilets
Disposing of black water is the primary challenge of having an off-grid system in your tiny home. Most people who live in traveling tiny houses choose a waterless toilet so they don’t have to worry about blackwater disposal.
A composting toilet is the top waterless alternative to the usual bathroom toilet. It’s cheap, accessible, and eco-friendly. Incinerating toilets, on the other hand, are more expensive but don’t require the same amount of maintenance.
Choosing between the two depends on your budget and preference. A high-quality compost toilet can cost anywhere from $1,000 to $2,000. Incinerating toilets cost $3,000 to $4,000.
Read our full review: Tiny House Toilets: Composting VS Incinerating
The main difference between the two is how waste is processed. With a compost toilet, waste is decomposed and turned into compost, which can be naturally disposed of. An incinerating toilet turns the waste into ash and requires no work at all.
Composting Toilet VS Incinerating Toilet
|Composting Toilet||Incinerating Toilet|
|Preparation||You would have to dig a composting site in a nearby location so you can move decomposed waste there||Has to be installed by a professional; no other preparations required.|
|Waste Disposal||With a slow compost toilet, waste is deposited on a bucket and slowly breaks down; for active composting toilets, bulking materials such as coconut husks are used to prevent odor and hasten decomposition||After flushing, waste falls into the incineration chamber and instantly turns into ash.|
|Odor||Can have odor. High-quality composting toilets have systems in place to ensure smell doesn’t linger throughout the tiny home||Odor is not as obvious and dissipates quickly|
How to Winterize Your Tiny House
Winterization is one of the most common plumbing woes of homeowners. Just because you’re living in a smaller home doesn’t mean you are spared from these responsibilities.
Both tiny homes on wheels and foundations have to perform regular winterization to protect the tiny home’s plumbing from freezing or bursting.
Here’s how you winterize your tiny home:
1) Insulate Your Water Supply
Insulating your fresh water supply is an easy DIY project. If you don’t want to deal with unhooking your supply line every night, insulation is a great long-term solution during long winters.
All you have to do is buy a heat tape or a cable, foam insulation, and duct tape. Wrap the heat tape around your water supply - this will prevent the water from freezing. The insulation serves as extra protection from the cold and prevents heat loss from the heating cable.
2) Run Hot Water Regularly
Run hot water every three to four hours to prevent the water pipes from becoming too cold and freezing. It’s an easy way to prevent your pipes from freezing during the day. However, all it takes is one cold night to freeze your pipes. Insulating your water supply is still the best solution.
3) Look For Exposed Pipes
Burying your supply line beneath the freezing line is a common practice for traditional homes - there’s no reason why you shouldn’t do the same for your tiny house on foundation. Consider reconfiguring your supply line entirely if burying doesn’t prevent the freezing problem.
4) Store Your Hose
If you’re just parked at a campground for a short time, consider just removing your hose at night. This will keep your hose from freezing, without having to set up a whole winterization system.
Read more in our previous post: How to Keep Your Tiny House Water Pipes From Freezing
Plumbing Alternatives: Setting Up a Rainwater Catchment System
A rainwater catchment system is a great alternative to plumbing. If you’re living off the grid and don’t want to buy constant refills, setting up a rainwater catchment system is another way you could bring water into your tiny home and just save the refill costs for potable water only.
Before setting up a rainwater catchment system, here are some things you need to consider:
- Do you live in a state where catching rainwater is legal? You can check out if it’s legal to catch rainwater in your area here.
- How much water does your tiny home consume? On average, the typical American people use more than 300 gallons of water which includes water for flushing the house toilet, showering, sinks, and everything else.
- Does your area receive enough rainwater to meet your needs? This would determine whether you are able to rely on your rain catchment system fully or partially.
- Do you have the space to catch rainwater? This would work best for tiny homes parked in open areas where catching rainwater is legal. Take into consideration trees and other obstructions that could keep you from harvesting optimally.
We personally think that setting up a catchment system is worth it if you’re living off the grid for long periods of time since it’s incredibly sustainable.
Is Plumbing for a THOW Hard?
At the end of the day, the system you create depends on you and your household. As long as you understand your needs, setting up your own plumbing will be straightforward and easy.
Hey, there! We're Ivan and Manuela from Croatia, and we're crazy about tiny houses. We don't own one (yet).
This website is a result of our passion to share all the knowledge, photos, tips and tricks that we were able to learn while studying everything possible about the tiny house movement.