Rarely does anything at the Finca go to waste. They use the grounds to grow enough food to feed the community. They compost all their food waste, get water from natural springs and even biodigest toilet waste that's returned to nature.
But it's not perfect, as the Hogans readily admit. The community of Finca Bellavista still relies on oil to power its trucks, which they use for everyday work and to explore outside. But they are actively looking for alternatives, such as all-electric ATVs.
In terms of lifestyle, residents have time to go out and explore nature, and still be productive. Even in the rainy season.
"You can tell time by the rain in the rainy season," Hogan says as the skies open up, more like an act of God than a rain shower. "It rains at noon every day."
Such routine comes with other benefits. "You don't have to sacrifice the luxuries of life anymore to go back to nature," says Lauren Lubin, 25, a Chicago native who shares the tree house with Kevin, the Canadian project manager.
They met while studying vegan cooking in Boulder, Colo., and she hopes to help with the gardening of the Finca. What's more, she says, she has recently finished writing a book on self-discovery, "The Rainforest Awakenings: A Mystical Journey Within", which she will self-publish.
"It will be the first book ever to be written and published from a tree house," Lubin says. People around the Finca are comparing it to "The Celestine Prophecy".
The Hogans chose to take the community off the electrical grid because Costa Rica is notorious for blackouts, despite its commitment to renewable energy, and it is a bit out of reach.
Relying less on electrical grids is increasingly common around the world, according to the United Nations Environment Programme, which not only lowers costs but also creates jobs.
"There certainly is a movement towards a decentralized system, particularly in the developing countries, primarily driven by the fact that in 2009 there was more money worldwide investment in new renewable energy than fossil fuels generation," U.N. spokesman Nick Nuttall told ABC News. "And, certainly, you're seeing in Asia, Africa and Latin America a move towards wind power, a lot of decentralized electricity."
Indeed, a recent U.N. report concluded, "The provision of power in areas that are not reached by the grid is an effective way to generate green growth and jobs, often in areas widespread and persistent poverty."
The Hogans are also devoted to the trees. Some of them are more than 300 years old, Matt Hogan says, pointing to one particularly large tree he calls "the mother of the forest."
The rainforests of the world house half the planet's species, but cover only 7 percent of the earth's land. And protecting them from loggers is a difficult task.
With this in mind, Finca Bellavista forbids the destruction of trees, relying on the only legally harvestable wood for construction material.
"The first rule for building sustainable tree houses," Hogan says, looking skyward: "No other trees are destroyed."