Tiny houses come with some amazing benefits for people who don’t desire to have a large amount of indoor living space. When designed appropriately, they’re able to accommodate every normal human need just as well as any larger structure.
One very important part of such an appropriate design is the house’s plumbing system. How do you plumb a tiny house, then?
Water In, Water Out: How to Plumb a Tiny House?
When designing and building your tiny house’s plumbing system, there are a number of important components you will need to consider:
- Whether your preferred lifestyle requires indoor plumbing in the first place
- Whether your system needs to work on-grid, off-grid, or both
- Water pumps and heaters
- Freshwater, graywater, and black water storage tanks
- The nature of black water and how to dispose of it
- Alternatives to using a black water system
- The nature of graywater and what you can do with it
You don’t necessarily have to have all of these components in your house, but each of them has to do with one of the ways a good plumbing system makes a tiny house even more liveable.
Does a Tiny House Require Plumbing?
Before we get started, it’s worth pointing out the possibility of building a tiny house that doesn’t use any plumbing whatsoever.
It is possible to build a tiny house that does not have any plumbing, but such a tiny house would of course function much differently from a regular house.
Such a tiny house would function more like a glorified bedroom than as a complete house.
A tiny house without any plumbing is one that wouldn’t be capable of having a functioning kitchen or shower inside. This isn’t an impossible living arrangement, but it’s much more difficult in the long run than what a useful plumbing system provides.
Living in this kind of tiny house would mean that you would have to depend entirely on outside sources for your water supply, and any activities that involve using that water. The most likely situations where this would work is if the tiny house were located adjacent to another house or a business such as a gym with facilities that the owner could access.
If you’re like most tiny home owners, though, you’re looking for a home that you can enjoy for more than just sleeping. It’s nice to be able to prepare a nice and inexpensive meal and make yourself presentable before heading out the door!
How to Supply Water to an On-Grid Stationary Tiny House?
On-grid plumbing for a tiny house built on a permanent foundation is pretty much the same as it would be for any other house. You’ll have an intake pipe that connects directly to the municipal tap water supply, and drains and sewage pipes that lead to local water treatment facilities or to a septic tank on the property.
In between that intake and those outflows, you’ll have all the usual pipes and fittings, and as long as the local utility has enough water, so will you.
How to Supply an Off-Grid Tiny House With Sufficient Water?
So, what if you’ve got a tiny house on wheels? How do you get water to run your sinks and showers? And where, pray tell, does it all go when you’re done using it? In this case, you’ll need to have RV-style water hookups and tanks, or some other kind of filtration and storage system.
With an RV-style system, you can draw freshwater from municipal utilities via a food-grade hose connection, and store it in a freshwater tank for a trip, to be pumped when needed. An alternative to this kind of plumbing is to simply draw water from natural sources and use a gravity-driven filter to make it safe for cooking and bathing.
You can get the water to that filter by either carrying it unto the house by hand in buckets or jugs, or by setting up more complex systems to connect the natural sources to your RV-style hookups. That can take the form of a well with a pump, or a pipe from a spring, etc.
Convenient Pumps and Helpful Heaters
Many of the uses for which an off-grid plumbing system is designed could not function without the use of at least one water pump to get the water up to sinks and showerheads with adequate pressure. An on-grid system, however, relies on the standard pressure that city water is pumped to every home with.
If you rely on city water pressure, make sure that your connections are strong, using brass fittings rather than plastic, and installing a flow regulator at the connection point. Sometimes local pressure can vary, and cause damage to weaker fittings.
If you’ll be moving or building your tiny house in a region with a cooler climate, you definitely need to take a look at having a water heater.
This applies whether your house is stationary or wheeled. The most appropriate sort of water heater for a tiny home would be a tank-less model, which saves a tremendous amount of space and energy. They come in both gas-fired and all-electric versions.
Different Kinds of Water Tanks
Once you’ve got the water inside an off-grid tiny house, you need a place to put it, and a way to move it around. For a mobile tiny house, some of the most essential plumbing components are the water storage tanks.
There are a few reasons why you’ll need to plan on having multiple storage tanks: one for freshwater, one for graywater, and possibly one for black water.
The freshwater tank is your reservoir of water that will be available to use when you’re on the road or far from water sources. The larger it is, the longer you can go without refilling.
Larger tanks take up more precious space, though, and they quickly increase the amount of weight you’re towing. At 8.34 pounds per gallon (1 kg/L), water is heavy! Planning for how to plumb your mobile tiny house therefore requires you to be very conscious of your water usage.
If your tiny house is stationary and built on a traditional foundation with on-grid utility connections, though, you most likely will not need any of these tanks.
What is Black Water?
Black water is toilet wastewater. That’s the simplest way to describe it. Once a volume of your home’s fresh water has been exposed to human fecal matter in a toilet, it’s essentially considered contaminated, and is unsuitable for any other uses until it has been treated and filtered.
It can harbor diseases, and it naturally produces toxic smells, making it dangerous in many ways.
How to Dispose of Black Water
As we noted earlier, an on-grid and stationary plumbing system will have built-in sewer lines that immediately remove black water from the home. Only a basic amount of regular maintenance is needed to make sure the pipes and toilet are in working order.
An off-grid or hybrid black water system, on the other hand, is going to be a bit more complex. In this case, Black water must be contained in a dedicated holding tank until it can be drained away at an appropriate facility. This usually means taking the whole house to an RV park, where the tank is drained via a specialized hose. After draining, sanitizing chemicals must be added to the tank to keep it clean. This is all very often an unpleasant chore that involves many uncomfortable smells and the risk of a toxic spill.
Composting Toilet: a Natural Alternative to Black Water
If you’d prefer to avoid the hassle of dealing with black water, you can. By installing a composting toilet instead of a standard water-flush toilet, you avoid not only all the foul mess of black water, but you also can potentially save several thousand gallons of fresh water each year.
This article is about plumbing, but a Composting toilet works without using any at all. It keeps solid waste dry and breaks it down, which makes it produce almost no odors. It stores liquid waste separately, so it can later be diluted with fresh water and safely used to provide nitrogen to plants or else flushed down a regular toilet where convenient.
Opting for a composting toilet in your tiny house means you don’t need to install a separate black water tank. That means saving a significant amount of space and weight. That’s a huge advantage for a tiny house!
What is Graywater?
Graywater is home wastewater that hasn’t come into contact with fecal matter. This primarily refers to everything that drains from the kitchen or bathroom sinks, and the shower. It is not as hazardous as black water. Depending on the kinds of soaps you use, graywater can even provide useful benefits.
On grid, it just drains into the same municipal sewage and water treatment network as the black water would. If you’re off-grid, though, it still needs to be properly stored and disposed of. Like black water, graywater usually drains into a dedicated holding tank. There’s a wider variety of available options in this case.
How to Dispose of Graywater?
Many tiny homes rely on a built-in graywater tank that can be drained by hose at a designated dump site. Others may use a portable tank with wheels that hooks up outside of the house and can be rolled away to a drain site when full.
A more nature-friendly option that you can consider: if you use only organic and biodegradable detergents and soaps, you can have your graywater run directly into a holding pond or an artificial wetland. You can even use it to irrigate a garden! If your tiny house is temporarily parked in a residential area, you can ask permission to water your host’s lawn with it.
Even if you don’t use organic detergents, your home’s graywater is almost always safer to pour out than the mix of soaps people use to wash their cars in the street. You just have to keep in mind that graywater dumping is not legal everywhere! Always check the local laws and regulations before draining it.
Always Consider the Context of Your Tiny House Plans
Where you put your tiny house and the way you hope to live in it will inform the way you need to design and build its plumbing system. Do you really *need* a dishwasher or a washing machine? Some tiny home owners do! Systems like those may make it harder to build an adequate off-grid plumbing system, so plan accordingly.
Once you know exactly which and what kind of appliances and fixtures you wish your home to provide you the use of, you can start planning where you’re going to put holding tanks, pumps, pipes, valves, drains, and electrical connections. And how much time are you going to spend either on or off the grid? Your plumbing depends on the answer.
The key is to plan ahead, check the local laws, and make sure that your house’s plumbing system makes sense for you!