Sara Gatcomb reports on the "tiny house" movement.

PORTLAND, Maine - Americans have historically measured success in square feet. A big house was something to work for. But a growing number of Mainers are choosing to drastically cut their living space - on purpose.

They're part of what's known as the "tiny house" movement, and they're living in spaces of 500 to 600 square feet, or less. Why do they do it? We sent Sara Gatcomb to find out.

They say when you build a tiny house, you build it like a boat, using every inch of space. Louisa and Foy Brown did just that. "We actually built the whole house up on water, which was sort of challenging in itself."

Though building their home was a challenge, the lack of living space hasn't been a problem. "You know, I feel as though the space is big enough for two people. It might be a little harder for three, and be impossible for four."

The Browns spent 10 years building the $60,000 home and now they live here for six months of the year as a way to save money. And saving money is one reason the tiny house movement is continuing to grow.

Ben and Sarina Speed, of Franklin, say they found it was cheaper to build a tiny house from scratch than to buy and renovate an old home. "The mortgage we took out at that point was probably $75,000," Sarina Speed says, "and that included the land, all the ground work and the building."

For the Speeds, a lower mortgage meant that one parent could stay home with their growing family. But this sort of lifestyle is, obviously, not for everyone.

"It's a bitch because you live by yourself and you truly understand all the great things that community gives you," says Jake Ryan. Ryan, a Portland architect, says living in a rural tiny house has its drawbacks. He lasted in his for about two years. "I moved out of my tiny house because it was lonely," he says. "And I missed people. You know, hermit poet only lasts so long."

And for the Speeds, it became clear that a tiny home couldn't accommodate two busy kids, so they expanded from 640 square feet to just under 1,000. "We homeschool, so we're home for huge chunks of the day and we need space to play and do our projects and not be right in each others faces all the time," Sarina Speed says. "I think if I had designed the house slightly differently back when we first built it I wouldn't necessarily have had to add on. But hindsight is 20/20."

Portland's Urban Planning Office receives a handful of inquiries about tiny house permits each year. But Director Jeff Levine says that doesn't necessarily reflect the true interest in the movement, because the tiny house community is well aware that permit requests are almost always rejected. "In most cases, they did not get a building permit and they are not legal houses."

According to Levine, tiny homes don't meet building codes, public sanitary codes or public health codes. He also says they rarely meet minimum square footage and head clearance requirements. And they are often illegally connected to sanitation systems.

Tiny home dweller Kit McCann didn't want to say where she was living, because she's technically not supposed to be there. McCann says that's because the tiny house movement is so new it seems to be caught in a kind of regulatory limbo. "It's hard; because tiny houses are in this weird grey area in between living unit and an RV, there aren't really laws written for us. It's hard to figure out how to follow through with zoning and to do it all correctly."

Some people avoid the laws by going to places where they don't apply - like on the water. That's what the Browns did. "We have no zoning, no taxes, nothing. We own the mooring so we don't have to pay for the spot."

And tiny homes aren't just for cost-conscious freedom-lovers. They can be used as summer homes, hunting lodges - and even as houses for the homeless. Rosie Curtis is an associate professor of architecture at the University of Maine at Augusta.

"My students this past semester started researching homelessness, and solutions to homelessness," Curtis says. "As a result of their research, they decided to design a tiny house community on the banks of the Kennebec River in Waterville."

Curtis says her students estimate Maine currently spends between $8,000 and $12,000 a year on a single person in subsidized housing. They're proposing a tiny house community for a fraction of the cost. Curtis says the time is right to move in this direction.

"So much of what has made America great has been about this idea of growing. We've reached the frontiers now, we're looking at limits," Curtis says. "How can things cost less? How can it take less space? I think the tiny house communities are a reflection of that and the changing values that we have."

To be successful, the project will require some source of financial support and will also have to meet existing codes. Or, says Curtis, the project could become the catalyst to change the current laws.

Until that change comes, Maine's tiny home dwellers will continue enjoying the quirks and perks of tiny living. "You crawl in bed up there and the skylight's right there," says Foy Brown. "And for me it's pretty fun."

Eliza Lambert contributed to this story. The tiny house video was shot and edited by Eliza Lambert and Sara Gatcomb.