Green architecture or, as it is sometimes called, sustainable architecture, aims to minimize the impact of building on the environment. Practitioners of green architecture consider the impact of materials on human health. They emphasize the importance of using local, nonsynthetic products, harvesting natural resources responsibly, recycling, and reusing materials from previous structures. Green architecture also stresses the importance of space efficiency. Developing structures and communities that will not strain natural resources or the environment ensures availability for future generations. This means considering the renewable resources like water and energy sources such as solar.
California Academy of Sciences
Renzo Piano (1937– ) designed a green roof for the California Academy of Sciences (2005–2008) that completely embodies these green building principles. The roof of the building was made of rolling terrain, and more than 1.7 million plants from nine different native species were planted on top of it. This provided a habitat for wildlife and encouraged settling of some endangered species such as the San Bruno butterfly. One of the earthen mounds forms a dome over a manufactured rainforest that stands four stories high. Mechanical windows were installed so that light and air can enter. A planetarium sits under the second mound. Right in the middle is an open-air piazza. Most of the administrative offices are situated so that they can receive natural light. The mound construction of the roof allows cool air to circulate down into the interior spaces underneath it. It also works to collect rainwater.
The roof soil provides an additional six inches of insulation. Below, the floors are heated by radiant hot water. There are also skylights for ventilation, heating, and air conditioning. The builders used steel from recycled sources. They harvested timber from yield forests. They recycled almost all the demolition debris and donated 32,000 tons of sand to local initiatives that were funding projects to restore dunes.
The U.S. Green Building Council (USGBC) runs a program called LEED (Leadership in Energy and Environmental Design), a green building certificate program. LEED certification is an honor and they search for the most high-performing green buildings. They rate projects that fall into the following categories:
Building design and construction
Interior design and construction
Building operations and maintenance
LEED is an internationally recognized ranking system that uses a combination of credit categories like location and transportation, energy and atmosphere, water efficiency, and indoor environmental quality. Based on these categories, a project can earn points. The number of points determines the level of LEED certification. The levels are certified silver, gold or, best of all, platinum.
The Phipps Conservatory and Botanical Gardens in Pittsburgh, Pennsylvania, developed the Center for Sustainable Landscapes. It has received all the highest certifications including the Living Building Challenge, LEED platinum (one of the highest points ever awarded). It was built over a site that was previously a brownfield that had been paved over. Onsite solar photovoltaics meet 99 percent of the structure’s energy needs. A single wind turbine meets the rest. There are also fourteen geothermal wells. The structure uses half the energy of a comparable office building.
The building achieves net-zero water by treating all gray water and black water onsite. It can then be used again for toilet flushing and for irrigating orchids. It also has systems for capturing energy that make sure none goes to waste. They recycle wastewater and collect rainwater, which ensures that the building’s owners never have to tap into city water. The area was formerly a brownfield, which means that the land was considered unsafe because of a pollutant. It has now been completely rehabilitated so that 150 noninvasive local plant species can survive there. The green roof holds eight-inch soil depth, which helps control the temperature in the building and prevents runoff. Wastewater is filtered in the wetland that has been constructed.
Whole-House Systems Approach
This approach considers all parts of a house and how the materials within a house might contribute to the house’s efficiency:
Heating and cooling
Windows and doors
Ultra-efficient (renewable energy systems)
Solar water heating
Advanced house framing, also called optimum value engineering, contributes to energy efficiency but also reduces both the amount of lumber used and the amount of waste created.
Some advanced ideas for building include straw bale homes, which involves post-and-beam construction or non-load–bearing construction. Straw bales are then used to fill in the framework. This is a very difficult process. Log homes use logs to provide both walls and insulation. Earth-sheltered homes can be either above or below the ground. These houses allow for ventilation and natural light. This helps with heating and cooling efforts.
The Boy Scouts of America established the Sustainability Treehouse (2013) in Glen Jean, West Virginia, as an educational structure. The development coincided with the Boy Scout’s new merit badge for sustainability. The architectural firm Mithun funded a sustainable education center. As you learn, you move up through the levels of the forest.
This structure is located in the forest of the Summit Bechtel Reserve. It was designed by Mithun and another firm, BNIM, to have the least possible impact on the environment. The house was built partially from a prefabricated structure; had they prefabricated the entire structure, they would have needed to use cranes that would have done considerable damage to the immediate environment. They used local materials such as black locust wood. Energy is derived from solar panels and two wind turbines and a large cistern that collects and cleanses rainwater. The structure is made of indoor and outdoor platforms that shoot straight up through the forest. Each platform houses an exhibit that allows visitors to learn about the ecosystem. Energy input and output combine to create a structure that yields net-zero energy and net-zero water use. Staircases connect the platforms and stretch from the ground to 125 feet high, above the treetops. Exhibit areas include topics like how to conserve water and tips for energy alternatives.