GREEN ACRE

With his long white beard, rotund frame and twinkling eyes, Al Attara could easily pass for a modern-day Santa Claus. But the lifelong New Yorker isn’t giving out toys to youngsters — he’s bringing downtown Brooklyn a communal spirit colored in green as the owner of 33 Flatbush Ave., a seven-story building that’s becoming an incubator for socially responsible and environmentally minded entrepreneurs.

Attara bought the property, the former Metropolitan Exchange Bank, back in 1978 with the idea of turning it into a professional arts complex. But he soon learned the city had marked the building for urban renewal and could reclaim it at any time — not an ideal situation for potential tenants. So for decades, the building was mostly a warehouse for the inveterate junkhound’s vast collection of salvaged furniture and curios.

Three years ago, the city’s claim expired and Attara was able to start bringing his vision to life. The first company to move in, in February 2007, was Interboro, an urban planning, design and architecture firm founded by four graduates of the Harvard design school.

With Attara, who has a background in design, Interboro soon founded the Metropolitan Exchange (MEx), a community-minded co-op that offers office space to other architects, urban planners and researchers with a progressive bent. Among them is Mitchell Joachim of the nonprofit ecological design firm Terreform 1, whose visionary ideas for re-imagining cities — like the City Car, a stackable car made of soft materials, and an airborne transit system using low-hanging blimps — recently earned him a spot on Wired magazine’s Smart List and Rolling Stone’s 100 People Who are Changing America.

That shared-office model has become a standard for the building: On the fourth floor is Treehouse, a budding “sustainable design community” formed by EcoSystems, an Earth-friendly furniture design firm that uses reclaimed materials and environmentally sound practices.

“It’s amazing to be here,” says EcoSystems director Andrew Personette. “You won’t find better rent or a higher density of geniuses anywhere else. There’s such a young, vibrant startup energy — we really all feed off each other.”

“There are no walls — literally or metaphorically,” says Personette.

The building’s green core, though, is found in Green Spaces, a co-op for start-ups that perhaps most closely adheres to Attara’s 1960s-style principles. Founded by former Wall Street banker Jennie Nevin, the year-old company rents space to eco-friendly entrepreneurs looking for an affordable and collaborative environment.

“When I left Merrill Lynch [in early 2007], people said, ‘Why are you doing this? How are you going to make money?'” says Nevin, 30. “But I had always had an interest in the green movement. When I saw it start to take off and involve real business solutions, I didn’t want to miss the boat.”

Fees start at $225 a month and tenants have access to desk space, wireless Internet, conference rooms, monthly workshops and interns. Among Green Spaces’ 26 tenants are Scryve, an online service that rates businesses according to their community and environmental behavior; Alive Structures, a certified green roof installer; FarmsReach.com, which offers Web support to small-scale farmers and local food sellers; and green guru Anne Lappe, a speaker on environmental issues and author of the best seller “Grub: Ideas for an Urban Organic Kitchen.”

“There’s an amazing pool of talent here,” says Nevin, whose vision was to bring together “all these people who are starting these great companies in different areas” and allow them to share contacts, exchange ideas and otherwise support one another.

“This isn’t just about giving people office space,” says Green Spaces partner Brad Holmes. “We’re creating more opportunities. You see lots of green businesses and collectives in Europe and on the West Coast, but New York is really an untapped market.”

Holmes is currently overseeing a contest sponsored by Green Spaces’ nonprofit arm that will award $25,000 in cash and services to a worthy start-up. (Semi-finalists are being announced today at the Go Green Expo in Midtown.)

Like all of 33 Flatbush’s collectives, Green Spaces is a vast, open space furnished with mismatched desks, chairs and tables Attara has amassed over the years, and decorated with paintings, sculptures and other artwork from his sprawling collection. Communal spaces with couches, stocked with copies of Wired and “The Green-Collar Economy,” as well as dominoes and a chessboard, help to foster a social environment, while a compost heap and a planned community-supported agriculture drop-off are among the ways Green Spaces practices what it’s preaching.

There’s no formal application process to rent from Green Spaces — Nevin sits down with potential renters to ensure they’re in line with the company’s Earth-friendly philosophy.

“They need to be setting an example with how they operate, like a paperless office, or working to bring a truly groundbreaking green product or service to the marketplace,” she says.

Alexander Gillett of Scryve said when he started looking for office space, Green Spaces was “a natural fit.”

“The energy here is kind of infectious,” he says. “Everyone is working with the same mind-set but we’re all doing something different, so we’re not competing with each other.”

Food is an essential part of the building’s communal spirit: Attara installed full kitchens on every floor to encourage workers to socialize and network. At Green Spaces, Kumquat Cupcakery and Early Bird Granola fill the air with tempting aromas and often offer samples to their neighbors, while the fair-trade coffee importer Crop to Cup keeps the workers buzzing with free java. Nevin has also instituted what she semi-jokingly refers to as a “Socialist lunch program,” in which members take turns cooking midday meals.

“The people here are all creative and focused on similar goals. Having lunch together gives them a chance to connect and share ideas,” she says. “And it’s a lot cheaper than ordering in all the time.”

Some raw materials may soon be provided by an organic farm that will be part of a green roof planned for the building’s rooftop — the seedlings are currently sprouting by one of Green Spaces’ picture windows.

Despite the current economic downturn, business is also blossoming. Green Spaces has seen the number of new members climb from one or two a month last year to nine in March alone.

Meanwhile, while 33 Flatbush is abuzz with activity most days, Attara’s vision for the building is far from fully realized. There are plans to add a gallery, a women’s writing workshop, a designer showcase and even an in-house day-care center. Attara also hopes to bring a sustainable-food restaurant to the building’s ground floor — if only to find a home for some of his eclectic furniture.

“It’s a work in progress,” he says. “It kind of evolves as people come to me with ideas. I’m an action-oriented kind of guy, so if something sounds good, we’ll try to make it work.”

Sea to table

Overfishing threatens much of the seafood industry, but Brooklynite Sean Dimin and his family, owners of Sea to Table, are helping fishermen who manage sustainable fisheries bring their undersea harvests to market.

While parents Michael and Tessa work with fishermen from Tobago, Alaska, Florida and other regions out of their home base in Florida, Sean manages the company’s New York sales office out of Green Space, supplying fish to Fresh Direct and local eateries such as Savoy, Cookshop and 100 Acres.

“There are a lot of chefs interested in sustainability, but it can be hard for them to find quality product,” says Dimin. “When they find out what we’re doing, they’re very eager to get involved.”

The company’s mission extends to education, as well: Esca chef David Pasternak recently joined Dimin and a group of NYU students on a 3 a.m. tour of the wholesale fish market at Hunts Point in the Bronx.

Denim Therapy

For those who hate to part with their favorite jeans no matter how tattered, Francine Rabinovich’s three-year-old company is a godsend. Denim Therapy finds matching colors and reweaves the fabric to keep old dungarees in circulation — and out of the landfill. Repairs cost $7 an inch, and business is steady — as the stacks of denim piled around her workspace attest. “Jeans are the most personal clothing people own,” says Rabinovich, a former branding consultant. “We’re not just extending the life of the denim, we’re extending our clients’ relationship with it.”

SunOne Solutions

With pending legislation expected to cap carbon emissions, large companies are looking for ways to offset their ecological impact. Enter SunOne Solutions, Green Spaces’ first tenant. Formerly with the World Bank’s Sustainable Development Group, founder John Hodges now helps sustainable farmers and ranchers earn carbon credits, which are then sold on the Chicago Climate Exchange.

“It’s fairly small right now, but it could easily balloon if new mandates are passed by the Obama administration. We could be looking at a $1 trillion market,” predicts Hodges, 38, who says a number of major corporations, including Ford and Hewlett-Packard, are already trading in anticipation of the new requirements.

SunOne currently has three full-time employees, but the business is expanding: Hodges has already brought in four contractors and expects to hire more.

Crop to Cup

Taylor Mork and Jose Aguilar began their fair-trade coffee import business in 2006, and moved into Green Spaces last fall.

“We can get shipments of 600 pounds in a day, so it was important to find a location that had flexibility as far as space and storage. Green Spaces was just ideal,” says Mork, who sells wholesale to local retailers including Fairway and the Park Slope Food Co-Op, and supplies restaurants and offices.

And philosophically, Crop to Cup fit right in, with a commitment to being green in every element of its business, from using organic beans to shipping its product with reused boxes, to roasting beans near the locations where they’ll be sold — thus cutting down their carbon footprint.

The company’s primary focus is on fair-trade practices –they pay family farmers in Africa 20 percent over the market price and donate a portion of profits to community development programs in their home regions. Mork, 27, who first got interested in the coffee industry while living in Uganda, notes that helping them earn a decent living is a way to help the Earth, also.

“These are the farmers who have an incentive to treat their ecosystem and soil well, since they’re literally living on that land and relying on it not only to produce coffee, but to feed their families and grow other crops to sell,” he says. “Ecology and poverty are intrinsically linked.”