NEW YORK — It may be that the house of the future is an apartment — at 420 square feet, a very small apartment — in a century-old tenement building on Sullivan Street.

Shiny and white, it has movable walls that allow it to morph from one room into six, as well as expandable furniture and filtered, or "country," air, as the owner, Graham Hill, put it recently while showing off the apartment's convertible tricks.

This laboratory, as Hill calls it, for small-space, sustainable and — it must be stressed — high-end living is the first tangible product from his fledgling company, LifeEdited. It comes with an awkward manifesto that nonetheless manages to gather an armful of social and economic trends and philosophies, including happiness research, the booming field of collaborative consumption (which uses new technology to share resources like cars, toys and books, on the Zipcar model) and data on the proven efficiencies of cities.

This is a medley of new-old systems that will be familiar to habitués of recent TED conferences, where Hill has been a featured speaker, and to frequenters of the self-help section of bookstores and even old-school urbanists and Buckminster Fuller fans.

"Design your life to include more money, health and happiness with less stuff, space and energy," as the manifesto reads, is both a mouthful and a paradox for an enterprise that hopes to be in the business of selling, well, lots of stuff, in much the same way the come-ons of the latest miracle diet promise weight loss if you gorge on all your favorite foods.

Yet Hill, the founder of TreeHugger, a website that made environmentalism attractive and aspirational by promoting a global, modern vision of sustainable design, has shown that he can profit from his own very sincere idealism and good taste. After all, he sold the site in 2007 to Discovery Communications, the company that owns the Discovery Channel, for $10 million.

Hill, 41, who is Canadian, is trained as an architect and a product designer.

TreeHugger, which went live in 2004, was his second Internet venture. His first, a Web design company, was sold in 1998 for $10 million as well.

"Graham is a rare breed, a pragmatic idealist," said his friend Nick Denton, founder of Gawker media. It was Denton who offered up Gawker's blogging platform as a template for organizing TreeHugger in its infancy. In return, Hill gave him a piece of the business.

"He's shied away from tokenism and from empty idealism," Denton added. "I think it's kind of cool for Graham to come up with a sustainable way of living in cities instead of showing million-dollar solar panels on houses in the Napa Valley, which is not the way most people live."

On the road

Indeed, the kite-surfing, skateboarding Hill has been mostly camping for the past decade, running his business out of a series of hotel rooms and small apartments in cities like Buenos Aires, Argentina; Bangkok and Barcelona, Spain, to name just a few, as well as from a trailer on the Baja, a garage in Maui and even a bunk on Plastiki, the boat-mission made from 12,500 plastic bottles and captained by David de Rothschild, the banking-heir environmentalist.

It was these experiences, Hill will tell you, which required culling his stuff to fit into one small rolling suitcase, that made him seize on the notion of "small" as a business plan.

"Small is sexy," he says in his six-minute TED talk. A YouTube hit, with more than a million views, it also includes these aphorisms: "Transfer ownership to access," "Own as little as possible so you don't have to store too much" and "Editing is the skill of this century: editing space, media consumption, friends."

Hill is certainly not the first to trumpet the benefits of a pared-down life. There's a straight line from Buckminster Fuller to Sarah Susanka, the architect and author of "The Not So Big House," published in 1998 at the height of the country's McMansion expansion, and to the Tiny House folks, the DIY builders of microhouses.

There are the clutter people and the simplicity people and authors like Dave Bruno, who wrote a book about editing his possessions down to 100 things.

Barbara Flanagan, an architect, product designer and writer, did Bruno two better, with her 2008 book, "Flanagan's Smart Home: The 98 Essentials for Starting Out, Starting Over, Scaling Back."

In 2009 and 2010, Hill bought two apartments in a tenement building on Sullivan Street: a 420-square-foot cube for $287,000 and a 350-square-foot cube for $280,000.

He camped in the smaller one and held a competition to design the larger space, with a brief that included the need to seat 12 at a dinner table and have guests sleep over, among other efficiencies.

There were more than 300 entries, and Catalin Sandu, a Romanian architecture student now employed by Hill, won for his transformer-style apartment, in a crowd-sourced selection process promoted by the TreeHugger site.

Zappos connection

Friday was Hill's first night in his new apartment, and he slept well, having arrived on the red-eye after a weekend of boar hunting in Texas followed by four days in Las Vegas, where he was pitching an investment in LifeEdited to Tony Hsieh, the billionaire chief executive of Zappos, the online shoe company.

Armed with ideas, as well as a passion for a Las Vegas bar called the Downtown Cocktail Club, Hsieh is investing $350 million in the area surrounding the bar to build a corporate campus for Zappos, as well as mixed-use developments that will incorporate a LifeEdited apartment building created by Hill and his new team, which includes Sandu and Guerin Glass, an architecture firm in Brooklyn.

This is where LifeEdited gets really interesting: Hill's group has proposed apartment buildings designed around large, open courtyards with units ranging from 300 to 600 square feet. It is quite something to promote studio-apartment living in a state that has so much housing stock available at such a steep discount. (Nevada still leads the country in foreclosures.)

Later this month, Hsieh will try it out for himself, when he comes to New York to stay in the LifeEdited apartment.

"It sounds great in a TED talk," Hsieh said. "But it's one of those things you just have to see."

Hill, whose possessions run to athletic gear and vitamins, has domesticated the apartment with objects belonging to his girlfriend, Kumara Sawyers, a massage therapist and yoga instructor. He chose a globe, an antique camera, an antler and a potted plant, along with a few books like Glaeser's. There were also products bought to illustrate LifeEdited principles, like a heavy fork that was supposed to do double duty as a knife but didn't work very well.

In the closets, there is a tiny wardrobe of merino wool, which Hill said needs less washing than other fabrics. The showstoppers were the Murphy bed designed by CLEI and the expandable dining table designed by Ozzio. The movable wall was pretty neat, too.

All in, the renovation of the apartment cost about $365,000, $50,000 of which went toward the accelerated deadline Hill gave his builders.

Since a goal is to offer LifeEdited apartments that save people "significant money," Hill suggested this calculus as a way of taking the sting out of the Sullivan Street price tag. He added up the square footage of the "rooms" created by the apartment — kitchen, bathroom, living room, dining room, office, master bedroom and guest bedroom — to 1,100 square feet.

"Looked at this way," he wrote in an email, "you're getting the functionality of an apartment almost triple the size. Granted, you can only use one space at a time and this requires a transformation but still ... "