The arrival of spring can be identified by seasonal characteristics, among them new blooms on the trees, more daylight, and crisp mornings followed by warm afternoons. for those seeking exemplary sustainable design and architecture, spring also brings with it the winners of the American Institute of Architects Committee on the Environment’s (COTE) Top Ten Green Projects. The 2011 winning projects, showcased on the pages that follow, are working examples of the power of a thoroughly integrated approach to architecture, natural systems, and technology.
Cherokee Studios, Los Angeles, Brooks + Scarpa
Residents at Cherokee Studios in Los Angeles enliven the streetscape and regulate their environment through a series of occupant-controlled perforated-metal-panel screens. Designed by Brooks + Scarpa, the project’s metal screens offer passive ventilation, privacy, and shade. Additional passive features such as building orientation, solar-ventilation chimneys, operable windows, and a private courtyard work together to make the building nearly 50 percent more energy efficient than similar conventional structures. A variable refrigerant flow system moves heat and cooling from one part of the building to another to meet demand, while the insulated building envelope, low-E windows, high-efficiency lighting, and occupancy sensors also minimize energy consumption in the building. The roof includes a 30,000-kilowatt solar PV system; as a result, tenants pay 30 to 40 percent less in operating expenses. Measurement and verification for the Living Building Challenge is currently being conducted and LEED Platinum certification is pending.
Team members worked with the city to change established standards. Zoning was altered to allow a live/work space; sidewalk width was increased and bike racks were added; and the project located the first privately funded stormwater retention system in Los Angeles’s public right-of-way. The retention system and a vegetated roof retain 100 percent of stormwater on site.
Vancouver Convention Centre West, LMN Architects
Aspiring to embrace a dense urban environment and strengthen landscape habitat, the Vancouver Convention Centre West reclaimed a former brownfield site and tripled the existing convention center’s size. The 22-acre development with 1 million square feet of convention space accommodates 225,000 annual visitors, and its 400,000 square feet of walkways, bikeways, public space, and plazas constitute a major public gathering space on the water. In addition, the center hosts 400,000 indigenous plants and 240,000 bees on a 6-acre vegetated roof—the largest of its kind in Canada and part of a chain of continuous habitat from the center to Stanley Park.
LMN Architects added an artificial reef below the waterfront to function as part of the natural shoreline and to support migrating salmon and other marine species. Highly efficient, hydroelectricity-powered seawater heat pumps heat and cool the center, and free-cooling economizers also cool the space in busy seasons. Innovative measures help the center reduce its potable-water consumption by 73 percent. For three-fourths of the year, an on-site bioreactor wastewater-treatment plant cleanses approximately 60,000 liters a day of black- and graywater for reuse in toilet flushing and landscape irrigation. During summer months, the facility uses sewage from cruise ships to augment lower sewage flow rates. The project is LEED-NC Platinum certified.
Livestrong Foundation, Austin, Lake|Flato Architects
When the Livestrong Foundation sought new headquarters, it chose to renovate a 1950s paper warehouse in an inner-city neighborhood in Austin, Texas. The office’s programming mimics its urban surroundings with a variety of distinct but interrelated neighborhoods. Lake|Flato Architects reduced the building’s carbon impact by retaining more than 80 percent of the existing 28,295-square-foot structure and reusing and recycling nearly 90 percent of construction waste on site. Salvaged-pine roof decking was remilled to construct flexible-use enclosures for the workspaces; existing concrete became retaining walls, garden elements, walkways, and a new entry; and composite beams were transformed into benches and furnishings.
The warehouse’s concrete walls and deep floor plate were challenges for passive lighting. The team reoriented the building’s approach and replaced the roof’s center bays with north-facing sawtooth clerestory windows to bring daylight and views to almost all of the regularly occupied spaces. Automated controls adjust light levels. The loading dock was transformed into a side entry with a vine-covered buffer that reduces heat gain, and a high-efficiency variable-volume refrigerant mini-split system offers employees zonal temperature control. The LEED-NC Gold–certified facility is designed to save 39.5 percent in energy costs over comparable offices.
Greensburg Schools/Kiowa County Schools, Kansas, BNIM
Citizens of Greensburg, Kan., joined together to rebuild after a 2007 tornado decimated 95 percent of the town, including its schools. BNIM helped three rural community school districts consolidate their K–12 education into one 132,000-square-foot school. The facility reinforces ties to the community by being located in the heart of town; opening two gymnasiums, the library, a distance learning center, and cafeteria to the public after hours; and providing shared outdoor recreational facilities.
The project is pursuing LEED Platinum certification. An on-site 50-kilowatt wind turbine supplemented with power from a nearby wind farm provides the facility with 100 percent renewable energy. Building orientation and operable windows offer daylight and ventilation, and structural insulated panels and a rainscreen cladding system lower thermal loads. The gymnasiums are daylit thanks to sawtooth, skylit roofs. These strategies combine to reduce demand on the mechanical system—a geothermal ground-source closed-loop heat pump. The school manages 99 percent of on-site precipitation through constructed wetlands and six cisterns that store rainwater for irrigation use. Condensation from HVAC equipment is reused as make-up water in cooling towers. Recycled and reclaimed materials include lumber from cypress trees salvaged from Hurricane Katrina and exterior paneling reclaimed from warehouses in nearby states.
Step Up on 5th, Santa Monica, Brooks + Scarpa
This mixed-use project provides affordable housing in Santa Monica, Calif., for those who are homeless or mentally disabled. Equipped with 46 apartments that are less than 250 square feet each, the building is within walking distance to the city center, has transit access to community services, and includes a ground-floor art gallery and studio to foster interaction between residents, artists, and the public. Brooks + Scarpa provided residents with a healthy environment through formaldehyde-free MDF cabinetry, low-VOC paints, natural linoleum, and fluorescent lighting with low mercury content. By leveraging prevailing winds, operable windows, and ceiling fans, the building enhances thermal comfort and natural ventilation, and eliminates the need for air conditioning in the apartments. The windows and two courtyards bring in ample daylight.
The building is designed to be nearly 50 percent more efficient than a conventionally designed project thanks to features such as double-glazed low-E windows, concrete floors and walls that act as thermal heat sinks, and a highly efficient hydronic heating system. The installation of a 30-kilowatt PV system will make the project a net-zero-energy building. The facility retains all stormwater on site through a subsurface infiltration system to prevent runoff into the Santa Monica Bay.
First Unitarian Society Meeting House, Madison, The Kubala Washatko Architects
In 1951, Frank Lloyd Wright designed the First Unitarian Society Meeting House in Madison, Wis., to hold up to 125 congregation members. Today, this National Historic Landmark serves a congregation of nearly 1,500 members. In 2008, a 20,000-square-foot addition designed by The Kubala Washatko Architects tripled the existing seating capacity with a 500-seat auditorium, and added office and amenity spaces. Parking, however, was reduced and bicycle storage spaces were added.
The addition mitigated localized flooding of neighboring properties through an 8,078-square-foot vegetated roof, an underground infiltration chamber, rain gardens, and bioswales that retain nearly all of the stormwater on site. The LEED Gold building’s narrow width and interior courtyards allow daylight to spill into 76 percent of the structure. Locally sourced materials include columns made from red pine salvaged from windstorm-felled trees, recycled-newspaper insulation, and local landscape stone. Thanks to a high-efficiency multiple-stage water-to-water geothermal heat-pump system of 16 250-feet-deep wells, radiant floor heating and cooling, and operable windows that ventilate and cool 73 percent of the building, the addition is 40 percent more efficient than a comparable facility, and its water use is 35 percent lower. So far, the facility’s energy performance is within 2 percent of models and a team from the University of Wisconsin-Madison is conducting ongoing post-occupancy evaluation.
Research Support Facility, National Renewable Energy Laboratory (NREL), Golden, Colo., RNL
The NREL Research Support Facility’s designers looked to the climate and ecology of Golden, Colo., to devise a deeply passive solution for the 222,000-square-foot office building that houses a data center. Committed to achieving a net-zero-energy building on an annual basis, architecture firm RNL sliced energy use by reducing loads. Narrow, 60-foot-wide office wings optimize daylight while shading strategies control solar gain. An underfloor air-distribution system delivers 100 percent outside air to offices, and operable windows offer cross ventilation. Decoupled from the space-conditioning system, the ventilation air is tempered by passive heat from a transpired solar collector on the south façades, which is stored in a large thermal labyrinth under the two main office wings. The labyrinth is also a thermal sink for the LEED Platinum–certified center’s reject heat.
Thermal mass and purging heat at night help keep the building cool, and water-based radiant heating and cooling systems are efficient. Overall, the facility is designed to achieve energy savings of 46 percent. A two-component PV system will provide 1.6 megawatts of renewable electricity; the second component will be installed later this year.
LOTT Clean Water Alliance Regional Services Center, Olympia, Wash., The Miller Hull Partnership
Educating the local community about the importance of water conservation drove the design of the LOTT Clean Water Alliance Regional Services Center in Olympia, Wash. The Miller Hull Partnership brought water to the forefront by prominently placing a reclaimed water pond spanned by two bridges that lead to the center’s entry. LOTT provides Class A reclaimed water to the community, and the project’s use of reclaimed water in its pond, toilet flushing, and irrigation of two large green roofs helps reduce potable water use by 80 percent over a comparable building.
The mixed-use facility includes a renovated 7,700-square-foot water-quality laboratory, 21,300 square feet of new offices, and a 3,500-square-foot education center. Certified LEED Platinum, the facility reduces energy 61 percent over ASHRAE 90.1 through a variety of passive and energy reuse strategies. Motorized louvers on the west and south façades prevent solar gain, reflect daylight across the stretched fabric ceiling in the office areas, and passively heat the space in winter. Clusters of existing oak trees now shade the north façade. Methane captured from wastewater treatment is used in a cogeneration plant and serves as a power loop connected to water-source heat pumps. Heat recovery from the laboratory’s fume hood exhaust system is used to temper outside air. To address future expansion of the LOTT facility, the roof deck and green roof on the fourth-floor office level can be removed and replaced with offices.
OS House, Racine, Wis., Johnsen Schmaling Architects
A mix of floor-to-ceiling glazing, outdoor rooms, and open views lend an expansive sense of space to a compact urban-infill home along Lake Michigan in Racine, Wis. Johnsen Schmaling Architects designed the 1,900-square-foot OS House with an 8-inch-deep superinsulated exterior rainscreen to protect the building envelope and to improve indoor comfort for the family of four who live there. Agricultural-based closed-cell expanding foam insulation supplies an R-34 value in the walls and R-53 in the roofs. Window sizing and placement help eliminate the need for artificial lighting during the day. A geothermal ground-source heat pump with a vertical-loop system heats and cools the home, and a solar hot-water panel augmented by a tankless hot-water heater provides domestic hot water. Photovoltaic laminates on the roofing membranes combined with a freestanding PV array generate nearly 70 percent of the home’s electricity.
Innovative framing techniques reduced construction lumber by 30 percent compared to conventional construction standards and decreased thermal bridging. The house is able to grow with the family, with a basement that can be converted into a bedroom and outdoor rooms that can be enclosed. The building materials and rainscreen inhibit mold and mildew. The project earned LEED Platinum certification, and the PV and geothermal systems’ performance will be monitored over the next few years.
High Tech High Chula Vista, California, Studio E Architects
Situated near a land mesa overlooking the Otay River Valley in Chula Vista, Calif., High Tech High Chula Vista sculpts a gradual separation between existing development and site ecology. Parking is layered toward development and followed by buildings, playfields, and a revegetated slope that blend into the environment. Studio E Architects designed the 44,400-square-foot charter school with three interior courtyards, operable windows, and vented skylights for daylight and enhanced indoor air quality. Large, south-facing PV-covered canopies shade the courtyards and meet nearly 80 percent of the school’s electrical needs on an annualized basis. Movable interior walls and roll-up doors create dynamic spaces that blur the boundaries between formal classrooms and the outdoors.
The school achieved a LEED Gold rating and Collaborative for High Performance Schools verification. Cost-effective modular building components can be relocated to offer future flexibility. To reduce transportation impacts, the school established a comprehensive transportation-management program that includes free transit passes for students in need, and will conduct an annual audit of transportation modalities and adjust its schedule and walking and bike paths in response to findings.