Up on the Roof, Cities Grow Green

Fall 2015
Brooklyn Grange’s second rooftop farm, atop the Brooklyn Navy Yard, was completed in 2012. Its first, flagship farm was built on the Standard Motor Products building in Long Island City in 2010. Together, the two farms cover 2.5 acres and produce more than 50,000 pounds of organic produce each year. Photo ©Anastasia Cole Plakias, www.brooklyngrangefarm.com, Brooklyn Grange Rooftop Farm

Urban farms bring new life to commercial buildings and local communities.

CULTIVATING BUILDING rooftops with organic produce wasn’t a career path architect Mary Ostafi ever imagined for herself while growing up in Chicago. But an “Aha!” moment struck during graduate school.  

“I always lived in the city but never really had an opportunity to grow fresh food or garden until 2011. But I remember hearing my mom talk about my grandfather’s huge vegetable garden near Chicago, where she grew up. She would pick a tomato off the vine, still warm from the sun, and eat it like an apple. That image stuck with me when I was in Europe earning my master’s in strategic leadership toward sustainability.” 

Ostafi’s interest in sustainable best practices while studying the built environment deepened her appreciation for the symbiotic relationship among infrastructure, agro-ecology and economics, from the impact building design has on energy efficiency and water conservation to the revitalizing effects of turning vacant city lots into productive urban gardens. 

Today, Ostafi combines her profession and passion for sustainability as founder and executive director of Urban Harvest STL, a nonprofit organization in St. Louis that promotes urban agriculture and teaches residents how to grow crops creatively in unused city spaces, such as building rooftops. 

Her latest brainchild is a 10,000-square-foot farm that debuted this summer atop a two-story self-storage facility in the heart of St. Louis, kick-started with $33,000 in funding through the Rally Saint Louis crowdsourcing program and a stormwater management grant from the municipal sewer district and the U.S. Environmental Protection Agency (EPA). 

“Our goal at the Food Roof Farm was to not only bring fresh organic food to people who live downtown, but to create an entire ecosystem for research and help support the social fabric of our neighborhoods,” says Ostafi.  

“We have a pollination garden with native plants and flowers as well as beehives to support a healthy habitat for one of nature’s most important pollinators. In our experimental area, we’re testing whether specially engineered soil, hydroponic towers or vertical systems are better suited for certain crops and yield more in the same amount of space. We’ll use our greenhouse for year-round production. And we’re involving our community in eco-learning and special events at a hub specifically designed for that purpose.” 

garden on a building roof

The 10,000-square-foot Food Roof Farm, located atop a self-storage facility in downtown St. Louis, is growing food for CSA members and for sale to neighborhood restaurants. A shed provides storage space, a greenhouse offers opportunities for year-round growing and a special events hub hosts eco-learning and other activities.

Thousands of people live and work within just a few blocks of the Food Roof Farm, the first to be located on a building in downtown St. Louis. Most of its rooftop is devoted to community-supported agriculture (CSA), a popular way for city dwellers to buy ultrafresh seasonal produce directly from a local farmer. CSA members (sometimes referred to as subscribers) typically buy “shares” from a farmer at the beginning of a growing season, which entitles them to a portion of the farmer’s next harvest. Once the harvest begins, subscribers routinely receive a portion of the produce grown.  

Food Roof Farm’s first harvest — expected in late summer or early fall 2015 — will be available for pickup each week by CSA members directly from the farm. Produce not distributed to CSA members will be sold to neighborhood restaurants. Ostafi will also donate some produce to a local charity that operates a food training program for the city’s homeless and at-risk residents.  

The farm also raises chickens and helps local residents grow their own vegetables in designated garden plots on the roof. In addition to educational workshops and open-air classrooms, Ostafi plans to host community volunteer days and farm-to-table dinners. 

Finding a Rooftop 

One of the biggest challenges Ostafi faced when starting the farm was finding a suitable rooftop. The search began in 2012, when a lease on the city’s first community garden, which Ostafi had also founded, expired. 

“Like many older cities, St. Louis doesn’t have much available or affordable land in the urban core. What it does have is a tremendous stock of historic buildings that were built like tanks in the early- to mid- 1900s with strong, flat roofs and structural systems perfectly suited for urban agriculture.” Her hunt for the perfect rooftop proved serendipitous.  

“A fellow gardener who brought her family to our community garden mentioned her husband co-owned a self-storage building across the street,” she recalls. “Our discussions and planning took off from there.”  

Ostafi says Beau Reinberg, who owns the facility with two other partners, got on board as he learned about the financial, environmental and social benefits of the rooftop farm. 

“As part of our lease agreement, we installed a new, top-of-the-line roof membrane with a long life expectancy,” Ostafi explains. “Because the green roof system also acts as an insulator, the building will use less electricity for heating and cooling, so the partners’ utility bills will be lower.” The neighborhood revitalization aspect of the farm was also key. 

“This building lies on an invisible line in St. Louis called the ‘Delmar Divide’ that’s like a dividing line of inequality,” Ostafi explains. (South of Delmar Boulevard, the population is predominantly white; to the north, most residents are African-American.)  

“By buying a previously dilapidated building on the north side of Delmar, Beau and his partners made an important statement about bringing our communities together. Now there are sand volleyball courts next door, where 200 teams play every week. They’ve turned a block of a street that no one wanted to cross into a community that’s welcoming and fun.” 

Reinberg says these factors and Ostafi’s background in architecture, design and sustainability “checked a lot of boxes” for the building’s partners. 

office building roof
garden and planters on a building roof

Before construction began (top photo), the urban rooftop was indistinguishable from its neighbors. Today (bottom photo), after installation of a roof membrane, it features garden beds, planters and a special events hub. Photos courtesy of Urban Harvest STL/Food Roof Farm

“Not only do Mary and her husband Joe, who’s also an architect, have a strong mission to build community and do something good for the environment, they also have the experience and acumen to structure the deal the right way and get it built,” Reinberg adds. 

“Creating a model rooftop farm in the urban core is more difficult than most people think. You need a roof that gets full sun, doesn’t leak, can handle added weight, has stair or elevator access and isn’t very high, so it’s not too windy. Self-storage buildings like ours and industrial warehouses are ideal for this purpose. 

“Every building owner looks at the highest and best use of their property in a deal. We also look at the most creative use to make sure a project is sustainable.  

“Generating additional property revenue and saving on utilities from a new roof membrane were two important goals for us. We also needed to be sure Urban Harvest was focused on the long term. A well-run organization with a full-time director like Mary and an active, professional board that’s well-versed in fundraising for sustained operations makes a huge difference. So does the right lender. Pulaski Bank, our community bank, understood the value of the rooftop farm and the good it would do for our city. Every element made this project work for our investment.” 

NYC’s Urban Agriculture Trailblazers

Among the earliest trailblazers of the urban agriculture movement is Gwen Schantz, chief operating officer and a founding partner of New York City’s Brooklyn Grange, the world’s largest rooftop farm. Brooklyn Grange covers 2.5 acres on two buildings, a flagship farm in Long Island City, Queens, and a second farm at the Brooklyn Navy Yard. Every year, the Grange delivers more than 50,000 pounds of organic produce to its CSA members, retailers, restaurants, markets and its own farm stand. It also operates chicken coops and more than 30 beehives. 

“Our idea to build the first farm gelled during the fall of 2009,” she recalls. “We gave ourselves six months to find a building, get a lease, build the farm and finance it.  

“Raising money was easier than finding a roof. A lot of New Yorkers, including investors and lenders, were inspired by our idea and supported us through a Kickstarter campaign and fundraisers. 

“There are plenty of big, old industrial buildings with flat roofs in Brooklyn and Queens, but in those days owners would turn us away, over and over again. We did our best to develop lease terms that would work for everyone, but at the last minute owners would get cold feet. Finally, in April 2010, we met with the owners of the Standard Motor Products building, who were trying to attract younger tenants and knew a green roof would be a big draw. We said we would pay for a 40,000-square-foot green roof, maintain it, open the farm to the local community and use it as an educational resource. They shared our vision. We immediately signed a lease and started building the farm in Queens the following month. When we moved in, the building was about 40 percent occupied. By the time the owners sold it last year it was full, thanks partly to our farm.  

“Once our second farm was operational, consumers started asking us to build them a green roof or vegetable garden. That side of the business sprung to life on its own, and design and installation services are what I do full time now. 

“Much of what we’re seeing in Queens and Brooklyn today are old factories and warehouses being converted into multitenant commercial spaces. Owners are trying to attract tech tenants who can afford high rents and like open floor plans that are easy to build out. New Yorkers are also coming to expect buildings with green roofs. They crave interaction with nature because they spend so much time indoors, and building owners are seeing the light.” 

To encourage green roof installations, New York City provides a one-time property tax abatement program of $4.50 per square foot (up to $100,000) for green roofs constructed on commercial or residential buildings. The program, which was set to expire in 2013, was recently renewed. 

The NYC Department of Environmental Protection also offers more generous green infrastructure grants to help mitigate stormwater runoff and sewer overflow, including $600,000 for Brooklyn Grange to build its Navy Yard farm. 

Canada Leads the Way

Rooftop farming is gaining momentum in Canada too. After more than a decade leading a software company, Mohamed Hage, founder and CEO of Lufa Farms, assembled a team of architects, engineers and marketing experts in 2010 to build the world’s first commercial rooftop greenhouse on an industrial building in Ahuntisic, Montreal. The 32,000-square-foot farm now grows enough food to feed about 2,000 people a week. Construction of a similar but larger (43,000-square-foot) facility atop a warehouse in Laval, Quebec followed two years later.

green house on top of an industrial building

Lufa Farms completed construction on its second rooftop greenhouse in 2013. The 43,000-square-foot facility is set atop a built-to-suit mixed-use building in Laval, Quebec.

For their first greenhouse, the Lufa team identified more than a dozen possible buildings by studying Google Earth images and satellite maps, searching for rooftops with the right size, sun exposure and access. They also pored over building plans to determine which could bear enough weight to support a farm. 

"We built our second site with the developer and architect from scratch, so we had the luxury of giving them our specs from the get-go,” Hage adds. “Today, we use a combination of both for our greenhouses: we use existing buildings and work with developers on new construction.” 

Hage and his team developed lightweight greenhouse systems and innovative hydroponics technologies that allow year-round growing in extreme climates and yield 10 times the crops grown in soil. The computer-driven system captures rainwater, recirculates irrigation water and nutrients, composts green waste and uses biological pest controls to get rid of harmful insects. 

“We design and operate greenhouses that are very easy to install, comply with international building codes and are incredibly light, so more building rooftops are suitable for this type of construction. Although industrial is ideal, building type doesn’t matter much as long as the roof is big and flat. Both our greenhouses sit on the roofs of mixed-use properties with industrial and office tenants,” Hage notes.

The entrepreneur, who traces his passion for sustainable food to a childhood in Lebanon, where most of his family were farmers, today grows some 50 varieties of produce. Lufa Farms supplements its own greenhouse production with other locally sourced foods like fresh bread, organic eggs and cheese.

“We harvest to order, which means our greenhouse crews arrive at the crack of dawn to pick the exact number of vegetables ordered online by our subscribers, pack them into baskets and deliver them within hours to more than 150 designated pick-up points for about 8,000 customers throughout the city. It’s a sophisticated yet scalable process driven by an e-commerce platform that populates our supplier portal, harvester portal and pick-and-pack modules.”

Hage believes his rooftop greenhouse system, food service and delivery model can be replicated in practically any city in the world and is in the process of putting together a franchise.

“The key is finding the right location in the right city, then reviewing the building plans to make sure the weights and structure allow for what we want to do.

“For building owners, it’s win-win. It doesn’t cost them anything because we pay for all the greenhouse installation and development ourselves. We rent the building rooftop. And we save owners money on their HVAC and stormwater management costs.”

For more information:

The Benefits of Green Roofs.”