EcoStructure May/June 2010 : Page 51
GRAY TO GREEN A PARK CULTIVATES NEW LIFE IN DOWNTOWN HOUSTON. Text KJ Fields G MAY/JUNE 2010 ECO-STRUCTURE 51 G
Gray To Green
A few years ago , a field and a line of oak trees was the only visual relief amid a swath of surface parking lots next to Houstons George R. Brown Convention Center. Even the nearby addition of Minute Maid Park, home of the Houston Astros baseball team, and the Toyota Center arena and entertainment facility in the early 2000s could not enliven the forlorn parcel wedged in the high-profile spot. Walking from the convention center to the central business district was like walking across the surface of the moon, recalls Guy Hagstette, president of the Discovery Green Conservancy.<br /> <br /> When the landowners of the field decided to sell in 2004, former Houston mayor Bill White forged a public-private partnership to acquire the site and combine it with city-owned land. The goal was to create an ambitious 12-acre park called Discovery Green that would serve the entire city. Hagstettes Discovery Green Conservancy was formed as a nonprofit organization to develop and operate the park. In all, the $125 million project includes a range of park amenities, art, and gardens; a cafe, a restaurant, and a park administration building; and a 600-space underground parking garage.<br /> <br /> A Houston park demands shade, so an existing row of trees on site was saved and supplemented with trees transplanted from a nearby site that was being redeveloped into multifamily residences. Landscape architects Hargreaves Associates in San Francisco and Houston-based architects PageSoutherlandPage collaborated on the site plan to place buildings adjacent to the trees.<br /> <br /> The conservancy planned to draw the community to Discovery Green with abundant programming, which posed a challenge to the creation of a green oasis. Intensive programming usually equates to a lot of paved space,explains Mary Margaret Jones, senior principal at Hargreaves Associates, so we concentrated all the major activities on the spine of a tree-lined promenade, which allowed us to keep green spaces in the outlying areas As plans evolved, the partnership decided to shape the park into a model for green practices. The park as a whole is LEED certified. The designers placed the Grove restaurant, the Lake House cafe, and the administration building (all of which achieved individual LEED Gold certifications) along the sites north-south axis to take advantage of optimal shade and capture maximum daylight.<br /> <br /> For protection from Houstons blazing sun, the architects added deep, shady porches on the buildings south sides. The buildings themselves act as shading elements on the north facades and the roof lines slope up to let light in. Atop the Grove, a vegetated roof off ers insulation, a reduced heat island, and herbs that are used in the kitchen.<br /> <br /> The restaurant has a series of patios, decks, and terraces, and the cafe has an extensive outdoor dining space. Lawrence Speck, principal of PageSoutherlandPage, oriented the buildings to benefit from the southeast prevailing breezes in order to create passive ventilation. Wherever we could make outdoor space, we did, says Speck. These environmentally treated spaces maximize the amount of time the buildings can go without air conditioning, which is extremely important in a hot, humid climate.Passive strategies are combined with renewable energy features. The cafe and administration buildings porches sport two photovoltaic arrays comprising a total of 256 solar panels that provide a combined power generation of 49.9 kW, enough to supply roughly 8 percent of the parks total energy needs. (The solar panels generation rates can be tracked online at my.sre3.com/discoverygreen.) In addition, solar hot water panels on the cafes roof provide hot water to serve the two buildings.<br /> <br /> Discovery Greens replacement of the surface parking with the underground garage significantly reduces the sites heat island effect. Another positive urban design element took shape over the parking garage entry.<br /> <br /> The team covered the slope above the descending concrete ramp with earth and grass so that it now provides casual seating space for performances on a nearby stage. The green roof is both functional and aesthetically pleasing, and the stairwell that emerges from the garage is composed of long, thin art pieces.<br /> <br /> Groundwater from the underground parking structure is collected in a drainage system that pumps it into the parks lake rather than the citys stormwater system or sewage drain. There, natural agitation and plants biofiltrate the groundwater to clean it, minimizing the need to purchase potable water to replenish the lake.<br /> <br /> Another consideration in site planning was Houstons location in the Central Flyway.a migratory route for numerous birds between Canada and Mexico. Jones says a mosaic of native plants and gardens supports the diversity of bird species on their journey from north to south (and vice versa), and that the habitat also draws butterfl ies.<br /> <br /> The park attracts economic activity as well. Convention center bookings increased by 18 percent in 2008, the year the park opened, and three projects are under way adjacent to Discovery Green: a 347-unit residential highrise, a 262-room hotel, and an 800,000-square-foot office building that was fully leased during construction.<br /> <br /> The park also is a hit socially, despite initial fears that a park located in a business-centric locale wouldn't entice families and local community groups. On the contrary, more than 400 events now are held on site each year, from Pilates classes and bicycle repair workshops to farmers markets, organic gardening classes, lunchtime concerts, and arts exhibitions.<br /> <br /> The project shows how the public and private sectors can work as a team to really get it right, asserts Hagstette. Each partner contributed what it does best, and we are all proud of the results.