The 10 Largest Green Roofs
Georgia International Plaza is a popular venue for outdoor events.
Georgia World Congress Center
3. Logistikzentrum, Bondorf, Germany. 50,000 square meters. Owner: BDL Bondorf Distributions-Logistik GmbH. 1998. The extensive green roof on this warehouse building 40 km southwest of Stuttgart was built in a period of four months. The three-layer system, planted with sedum and grasses, includes ground-nesting sites for birds, and attracts wild bees and butterflies. Combined with cisterns, the system manages stormwater �ecologically� without any connection to the local sewer system. It was designed by landscape architects Stotzer & Neher. The green roof system was supplied by Optigreen, and represented 2% of the building�s total construction cost.
Optigreen
1. Millennium Park, Chicago, USA. 99,127 square meters. Owner: City of Chicago. 2004. Sitting atop a massive train yard and two parking garages, Millennium Park is a green gathering place in downtown Chicago. Its centerpiece is a 4,000-seat Frank Gehry-designed music pavilion of stainless-steel spirals. The Great Lawn accommodates 7,000 additional concertgoers, and is laced by a trellis containing a speaker system. The 2.5-acre Lurie Garden contains flowers and prairie grasses native to Illinois. Boardwalks, fountains, and other water features afford tourists and office workers alike relief from the urban crush. Gustafson Guthrie Nichol (GGN) designed Lurie Garden, and Terry Guen Design Associates was the coordinating landscape architect. Jaume Plensa designed the Crown Fountain.
SOM | � James Steinkamp, Steinkamp
9. Republic Polytechnic, Singapore. 25,013 square meters. Owner: Republic Polytechnic. 2006. This 12,000-student campus features 8 to 11-story buildings and a series of sunken courtyards and plazas with large areas of green roofs serving as walkways for easy circulation. The campus was designed jointly by Japanese architect Fumihiko Maki and DP Architects of Singapore, with Ohtori Consultants serving as landscape consultants. The green roof system, consisting of interlocking sub-surface drainage modules, covered with geotextile filter fabric with planting soil on top, was supplied by Elmich Pte Ltd.
Elmich Pte Ltd.
Wrigley Square is a section of Millennium Park containing the Millennium Monument, a semicircle of Doric columns that originally sat in this area of Grant Park between 1917 and 1953.
SOM | � Peter Barreras
4. Expo Zaragoza Empresarial Business Park, Zaragoza, Spain. 43,172 square meters. 2008. Zaragoza was chosen to host an international exposition in 2008, with the theme of �water and sustainable development.� 104 countries participated, plus dozens of companies and NGOs. The site was on a finger of land formed by the meander of the Ebro River. In keeping with the conference theme, it was decided to build a green roof atop the international pavilions, a long, curving, three-segment building, plus four smaller adjacent buildings. Botanist and landscape architect Carlos Avila designed the roof, with a base layer of Zoysia grass, and large beds of ornamental grasses, perennials and aromatic plants, serviced by a drip-irrigation system. It has wooden walking paths and a section of photovoltaic panels. ZinCo supplied the green roofing system, which has a 25 cm thick topsoil system. After the exposition ended, the pavilions were converted into use as a business park.
ESTUDIO DE PAISAJISMO
10. Vancouver Convention Centre, Canada. 24,282 square meters. Owner: B.C. Pavilion Corp. 2009. The Convention Centre expansion was a very challenging project, as two thirds of the building�s footprint is over water. The green roof blankets the �folded� roof plate, parts of which slope at angles as much as 56%, which offered additional challenges. PWL Partnership Landscape Architects designed the green roof. Flynn Canada was the roofing subcontractor, and Holland Landscapers installed the green roof overlay.
Courtesy Vancouver Convention Centre
Expo Zaragoza's green-roofed pavilions have now been converted into a business park.
ESTUDIO DE PAISAJISMO
5. Dearborn Truck Assembly Plant, Dearborn, Michigan, USA. 42,179 square meters. Owner: Ford Motor Co. 2002. In 1999 Ford Motor Co. embarked on an ambitious plan to transform its River Rouge manufacturing complex. William McDonough, a leading advocate of environmentally benign design, led the design team. �McDonough worked with Dr. Clayton Rugh [manager and technical director of Xero Flor America] and Michigan State University,� according to Mike Longfellow-Jones, Manufacturing Planning Facilities Manager for Ford. One major feature of the makeover was the living roof on the Dearborn Truck Assembly Plant. Xero Flor America supplied the green roofing system, consisting of pre-grown vegetated mats of sedum. Below the mats are three layers: a polyethylene root barrier, a drain mat of perforated geotextile fibers and a synthetic fleece layer for water retention and filtration. The green roof diminishes stormwater runoff, doubles the life of the roof, provides insulation, reduces cooling and heating demands by 5% and absorbs carbon dioxide to reduce greenhouse gases, according to Ford. The project also solved an environmental problem. To meet EPA regulations concerning runoff, Ford was facing a bill of about $50 million to build a mechanical water treatment facility. The green roof cost about $15 million, and eliminated the need for the conventional approach. The roof�s performance over its lifetime has been �outstanding,� says Longfellow-Jones.
Brad Temkin
7. Georgia International Plaza, Atlanta, Georgia, USA. 28,243 square meters. Owner: Georgia World Congress Center Authority. 1996. The Plaza is a seven-acre park atop a seven-level underground parking garage. The Plaza links the Georgia Dome, home to the Atlanta Falcons football team, the World Congress Center, Atlanta�s major convention center and Philips Arena, the home of the Atlanta Hawks basketball team. The Plaza was built as part of the 1996 Olympic Games, when both the Georgia Dome and the World Congress Center hosted numerous sporting events.
Georgia World Congress Center
Green roofs, which can found all over the world, are now seen as having a positive impact on property values.
ENR Art Dept.
6. Rolls-Royce Goodwood Plant, Chichester, West Sussex, England. 32,000 square meters. Owner: Rolls-Royce Motor Cars. 2003. After BMW won control of Rolls-Royce from Volkswagen in 1998, it was faced with having to build a new production facility. Rolls-Royce wanted the facility to fit in with it's tranquil surroundings as much as possible, and hired architect Nicolas Grimshaw, known for designing the Eden Project, the world's largest greenhouse. Located in a former gravel pit, the glass-walled, semi-sunken plant is barely visible from the neighboring Downs due to the landscaped roof planted with sedum.
Rolls-Royce Motor Cars Ltd.
8. Village on False Creek, Vancouver, Canada. 26,664 square meters. Owner: City of Vancouver. 2010. As the site for the athletes� Olympic Village for the 2010 Winter Olympic Games, the City of Vancouver selected a 25-acre brownfield site on the south side of False Creek, an inlet off English Bay. They selected the Millennium Development Corp. as the developer. Roger Bayley served as Millennium�s design manager, overseeing a team of five architectural firms that designed the 21 multi-story building complex. Passive design principles were emphasized, and the complex received LEED Platinum as a neighborhood and LEED Gold status for the buildings. Green roofs cover most of the buildings and courtyards, and include water features such as fountains and streams. Durante Kreuk served as the landscape design firm for the complex. Most of the rooftops were covered in sedum, provided by Xero Flor. Following the Olympics the 1,100 apartments went on sale, most at market rates, and 350 as affordable housing units.
John Sinal for The Village on False Creek
2. Frankfurt International Airport, Germany. 80,000 square meters. Owner: Fraport AG. The airport�s Terminal 1 building opened in 1972, and its 17,000 square meter green roof was probably one of the first large airport buildings in the world to have a green roof. �The basic idea was to restore green areas that had to be cleared away for constructing a new building: thus a green offset by implementing a green roof on top of the new building,� says Robert Payne, spokesman for Fraport AG. The greening program at the airport has continued over the years, and now covers 80,000 square meters of landscaped roof area on multiple buildings. �The plants have proven to be remarkably heat-resistant and therefore help to cool down the entire terminal building,� says Payne.
Fraport AG
One of the earliest green roofs on a commercial building in the U.S. was the Weyerhauser corporate headquarters in Federal Way, Washington, completed in 1971. The five-story reinforced concrete building features 134,218 square feet of its stepped overhangs sheathed in English ivy. The green roof was designed by landscape architect Peter Walker, of Sasaki Walker Associates.
Work Under Way
Two of the largest green roof projects under construction in the world are both atop water plants. The Victorian Desalination Plant in Wonthaggi, Australia, near Melbourne, will have a 26,000-sq-meter green roof with indigenous plants to camouflage the plant and provide corrosion resistance, thermal control and acoustic protection. It is expected to be completed next year, and will be the largest green roof in Australia.
The Croton Water Filtration Plant, taking shape in Bronx County in New York City, is sited on a golf course. As compensation, the plant roof will support a 36,512-sq-m golf driving range, which is expected to open in 2014.
Green roofs are now seen as having a positive impact on property values. "Green roofs increase energy savings. They positively impact the building itself as an amenity for the residents, and the buildings around ones with green roofs get the 'park effect,'" comments Somerville. "Looking at a green roof allows the neighboring building owners to command greater rents."
Politically, green roofs have gained support. "We're at the point now that it's a major part of the dialogue with public officials," Somerville adds. "Landscape architects are no longer having to put the value proposition out there. There's nothing but growth in the future of green roofs."
Visit our ">slideshow, where ENR rounds up the 10 largest green roofs in the world by square footage.
