Living in a smaller, more energy-efficient home is but one of many possible steps that one can take toward a more sustainable lifestyle. One might also choose to compost, grow one's own food, collect rainwater, or use alternative sources of energy or transportation. Green living author and anti-food waste activist Rob Greenfield -- best known for his 4,700-mile bicycle journey to raise awareness about food waste across the United States -- is a great example of someone who transitioned from living an 'ordinary' consumerist lifestyle, to one that he now hopes has a lighter impact on the planet.

We last saw Rob in his self-built $950 tiny house in San Diego; he's now moved onto yet another tiny home in Orlando, Florida that's he's built himself using mostly recycled materials. Here's a quick tour of the home, and Rob's outdoor kitchen, garden, home biogas cooking system, and closed-loop composting toilet system. Remember, everything you see here ultimately cost Rob only $1,500 to set up:

Rob's 100-square-foot tiny house is simple but suits his needs perfectly: the structure has been built mostly with recycled materials like pallet wood, flooring, leftover burlap, and reclaimed windows and doors. There's a simple bed elevated on top of a platform with storage below, along with a desk made with pallet wood. Rob has also set up an extremely energy-efficient refrigeration system using a deep chest freezer.

Currently, Rob is working on a long-term project where he's experimenting with growing or foraging 100 percent of his food. Thus, though there are a couple of shelves dedicated to personal effects like books and a minimal amount of clothing, most of Rob's shelves are dedicated to storing seeds, preserves and fermenting things like jun (similar to kombucha, but using green tea and raw honey rather than black tea and sugar), fire cider and honeywine. Rob also keeps bees and makes his own honey -- last fall, he harvested an impressive 75 pounds of honey!

Unlike his previous off-grid home in San Diego, Rob chose to use an extension cord that connects back to the main house for electricity. He explains that since he's only here temporarily for two years, and his energy usage is only $100 per year, he decided that it was more cost-effective to pay for electricity in this way, rather than investing in a solar power system.

Rob's outdoor kitchen is simple too, but has been well-considered: for cooking, he uses a combination of three options: not-so-green propane, as well as a solar oven, plus a home biogas cooking system (food waste from a local restaurant goes in, methane gas for cooking and fertilizer comes out). In addition to a countertop Berkey water filtration system, there's a compost bin nearby where he tosses any food scraps and yard waste. The kitchen is lit with LEDs that are powered by a rechargeable battery and portable solar power panel.

Rob's water system is pretty straightforward: he collects rainwater from the roof of the tiny home and the main house into one of the several blue storage tanks that he has, and either filters it for drinking, or uses it for showering.

Rob has also set up what he calls a "100 percent closed-loop composting toilet system," which involves having two separate toilets: one for urine and one for solid waste. Urine is diluted with water in the bucket at a ratio of 1:10, and can be used to water fruit trees. Solid waste is mixed with sawdust and composted for one year to create humanure, which is safe to fertilize fruit trees.

For transportation, Rob bikes around, and also uses a cargo trailer to haul things like furniture or other bulky items around.

Perhaps most enchanting of all is Rob's toilet 'paper' -- actually, soft and good-smelling leaves harvested from a Blue Spur flower (Plectranthus barbatus) plant that Rob has grown himself on-site.

Rob Greenfield / YouTube/Video screen capture

Such an ultra-simple lifestyle might not be for everyone, but Rob's aim is to inspire, to lead by example and show that small, personal choices toward sustainability are indeed achievable.

We might even think about changing our transactional interactions with others too -- as Rob explains in the video, he's set up his home in the backyard of a homeowner with whom he has a two-year work-exchange agreement with. For the last 25 years, this homeowner has wanted to set up a homestead, and Rob is finally helping her realize her dream -- in exchange for living in the backyard for two years. Once the two years is up, Rob will move on, and even Rob's tiny home will revert back to the owner to use as she pleases. As Rob eloquently emphasizes:

It's an exchange, rather than a monetary transaction. Instead, it's how we can work together to meet each other's needs, and that's what my life is all about: reducing the ways that we have to work for money, and instead, [asking] how we can work together to help each other out.

It's a positive message, coming from a man who isn't afraid to live according to his values; to find out more, visit Rob Greenfield and check out his book.