One of the great draws of a tiny home is that you can live off-grid and enjoy a nomadic lifestyle. If, however, you’re building a tiny home, accessory dwelling unit, or modular or prefabricated home on a small city lot and have access to a perfectly functional electrical grid, water supply, waste system and so forth, your best bet is to use these services and amenities.
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In BC, where I live, most of the electrical grid is fed by renewable energy sources, including hydroelectric and wind power. In fact, in Canada as a whole, renewable energy sources currently provide about 18.9% of the country’s total primary energy supply, and this is growing. If the same is true where you live, consider whether your tiny home design really needs to have a propane-powered stove and heating system or use up precious metals and other materials in order to have a snazzy solar array or wind turbine.
If you’re looking more for a back-up system in case of emergencies, this will probably look quite different to a system that is designed to meet all your needs 24/7. It should also be noted that propane is one of the worst fuels to use for indoor cooking as it poses a serious risk to indoor air quality. Put simply, if living off-grid is actually going to increase your carbon footprint, consider why it’s so appealing to you, if it’s really necessary, and if there are more eco-friendly ways to do it.
Eco-friendly off-grid living
If you’re committed to the off-grid lifestyle but have some qualms about relying on a gas generator or propane for cooking and heat, read on.
In almost all cases, you will be better off building in energy efficiencies to your off-grid home rather than trying to figure out how to meet higher energy demands in a sustainable way.
For instance, by altering the shape, design, and foundation of your home you can limit opportunities for heat loss and install more insulation. This will reduce your reliance on electricity and other heat sources, meaning that you can meet your needs with a much smaller solar array or wind turbine.
You will also want to think about installing an effective energy and/or heat recovery ventilator (ERV, HRV) system in your home. HRVs are mandatory in many jurisdictions to adhere to building codes, they are also required for LEED qualification as well as for several other systems, including Passivhaus and Novoclimat, and for good reason; a top of the line HRV can recover up to 90% of the heat from air as it is vented from your home. This can lower your energy consumption and heating costs dramatically.
There are also benefits to ditching the dream of an attached solarium or greenhouse. I’m a big fan of growing my own food but trying to do this to any extent inside your home will set up an epic battle between your plants and your dehumidifier. I’m not kidding.
To stay healthy, you need the air in your home to be at around 50%. A lot lower than that and you’ll get cracked lips and nosebleeds (I visited Ontario in winter this year and boy did I miss the humidity in BC). That said, if humidity is too high, which happens when you have a lot of plants in your home, you’ll get mildew, mold, and all the problems associated with these, including asthma, allergic rhinitis, eczema, respiratory infections, and even rheumatism.
Growing plants indoors is not the only cause of high humidity and associated mold and mildew, though. Building an off-grid home below grade (i.e. below ground), such as an earth-sheltered home, also poses some serious challenges for moisture control. Walls cannot dry out when they’re stuffed into the earth itself, and using the wrong kind of construction materials, improper insulation, or none at all, can quickly cause your home to become damp. This will mean you need to use more energy heating and/or dehumidifying your home, making it more difficult to live sustainably off-grid.
Your best bet for an eco-friendly off-grid home is to take advantage of passive heating and cooling as it works best for your lot orientation, climate, and lifestyle. Instead of growing your food indoors, build your raised beds and a greenhouse close by that you can gaze at fondly from the other side of your thermal windows that are blissfully free from condensation. You may even want to consider a green roof, but only if you have the right structure to support it and a seriously good membrane in place to make sure you don’t have leaks.
Some off-grid homes in my local environs use microhydro systems to generate power. I got a little bit obsessed with microhydro a few years back but as I lived in the city at the time, there wasn’t much opportunity to give it a whirl. I was born and raised in Sheffield, England, where there are seven rivers and a long history of industry powered by waterwheels. It’s especially appealing to me to, then, to install a mini waterwheel should I have the good fortune to build a home with a creek or stream on the land.
Microhydro systems are quite popular for off-grid homes in the Pacific Northwest, thanks to the hills, mountains, and rain. Microhydro is basically a very small waterwheel that sits in a stream or creek, generating electricity as the flow of water downhill turns the wheel.
These systems are cheap, easy to assemble, fairly straightforward to maintain, and work year-round, come rain or shine (barring serious droughts). They are dam-free and have a negligible impact on local ecology. Even a small stream can generate clean and consistent renewable electricity at a lower price per Watt than solar or wind. If you have a longer, fast flowing stream on your property, you can connect several microhydro wheels to generate a significant amount of energy.
Microhydro is basically useless in the rest of Canada and much of the U.S., however, given the flat land, dried up water sources, and freezing weather.
Thankfully, there are other good options for powering your off-grid home. Solar radiation is also much more reliable in places other than the west coast, especially in the sunny interior and southern states. As for the east coast, wind power is likely a good bet for powering your off-grid home.
For off-gridders in the city, you might also want to think about ditching your gym membership and setting up a bicycle generator! Just 15 minutes of cycling can power your laptop for an hour. One eco-friendly power generating gadget I’m currently coveting is the Green Microcycle Read and Ride Bike. Who needs a stand-up desk when you can both work and work out at the same time!?
So, despite my reservations about blindly embracing off-grid life and assuming it is more eco-friendly than on-grid, there are advantages if it’s done right. What’s more, living off-grid in a tiny home on a tiny plot in the city, and generating your own renewable energy rather than tapping into an energy grid powered by fossil fuels is probably far more eco-friendly than living off-grid in a rural location. Why? Because in a city, you can bike, walk, or take public transit most places you need to go, whereas a rural off-gridder will likely be car-dependent.
Fuel sources, radon, and air-quality
I’ve touched on this already, but it bears repeating. Living off-grid and relying on propane, or even a wood stove, for heating and cooking isn’t necessarily more eco-friendly than taking advantages of the electrical grid powered by renewable energy. There are also issues of air quality with propane and wood as fuel sources. Indeed, you’re far more likely to have safety concerns such as carbon monoxide poisoning (which can be fatal) in a tiny home or small off-grid cabin that has an open fire place or leaking wood stove, or other unvented combustion appliances.
If you are using combustible appliances, make sure they are properly installed and well maintained. You’ll also want to install a carbon monoxide detector.
Radon is another thing you need to think about when considering living off-grid in a tiny home. Radon is a colorless radioactive gas that can cause lung cancer. It is responsible for 21,000 deaths every year in the U.S.
This gas seeps out of the ground and up into your home. The first level of your home is most at risk for high levels of radon. For tiny homes and many off-grid prefabricated cabins, the first level is the only level of the home. If you move your home to different locations where you’ll stay for a few weeks or months at a time, it is essential to test the ground for radon and install a system to remove radon from your home. Even on the same lot, relocating your home just 50 feet away could mean dramatically different levels of radon. So, you’ll want to test radon levels every time you move your tiny home.
Radon charcoal testing kits cost around $20 and get you results in around three days in most states (you have to send test strips to a lab). A continuous home radon testing kit is a good option if you’ll be moving your tiny home to different places. Otherwise, testing costs can rack up quickly. This kind of system gives you results within 24 hours and doesn’t require sending samples to a lab. Radon testing matters. It could save your life.
An Active Soil Depressurization (ASD) system is the most common method of removing radon from a home. It operates much like a vacuum cleaner, with a radon fan drawing radon up from beneath your home and venting it above your roofline.
Because most tiny homes are built with a tight seal, they trap radon (as well as moisture and particulates in the air), which can put you at greater risk than you would be in a conventionally built home. As such, you’ll want to be sure that your prefabricated off-grid home or tiny home has a properly installed ASD system. This can be attached on an exterior wall, where it won’t take up scarce interior space.
If your tiny home is on wheels, the gap between the home and the ground does offer some natural ventilation for radon, but this may not be enough in an area where radon levels are high. Don’t, therefore, rely on this as your only method of radon mitigation.
Final thoughts on off-grid living
In summary, living off-grid isn’t inherently more eco-friendly than living on-grid. Indeed, buying a brand new all-in-one off-grid tiny home could give you a false sense of security (and smugness, let’s be honest), especially if you proceed to drive it around on the back of a gas-guzzling truck. In general, though, off-grid homes necessitate a design that is much more energy and waste efficient than a conventional home. They are usually better insulated, have fewer energy needs, and are powered with sustainable energy such as solar, wind, microhydro, or pedal power.
If you have experience living off-grid, I’d love to hear from you!