The heating, cooling and lighting of our buildings accounts for 48 percent of all U.S. energy consumption. As such, building energy usage is the greatest contributor to green house gases and global warming. This will only increase as the world becomes more urbanized and the built environment represents a greater and greater portion of our environment. Stormwater runoff from buildings is also one of the greatest non-point sources of water pollution, while the manufacturer of synthetic materials used in the construction of buildings leads to hazardous waste and an increasing number of "sick" buildings. Following is a discussion of methods of constructing "green" buildings so as to promote a more sustainable environment.
Monday, May 4, 2009
Green roofs are one of the most visible ways to build more sustainable, "green" buildings. A study conducted for Toronto, Canada estimated that the installation of green roofs on buildings could: reduce the heat island effect of urban areas by 1 to 2 degrees C, reduce smog alerts in cities by 5 to 10 percent, absorb CO2 emissions from automobiles and thus reduce green house gases, reduce the energy needs of buildings for heating and air conditioning, filter storm run-off and thus reduce water pollution, and expand recreational and open space in urban areas by creating roof-top gardens.
Solar photovoltaic panels are used to convert the sun's energy into electricity. A converter is used to convert the electricity from DC to AC electricity. Any excess electricity can be stored in batteries or exported to the electrical grid and sold to the local electrical utility.
Passive solar is any means to use the heat from the sun to provide for the heating or energy needs of a building without any means of mechanical assistance. The easiest method of passive solar involves the proper siting of a building to take advantage of the sun when it is at a low horizon or angle, but to provide shading when the sun is at its highest during the hottest part of the day. Another means of passive solar design is to build the floor of a building with some type of thermal mass such as concrete that absorbs the heat - and releases the heat at night when it is cooler.
Previously, wind turbines as an energy source were typically not located on building or within urban areas. With the concern about green energy and global warming, however, new technologies have recently been developed to allow wind turbines to be built on top of buildings -- and be able to deal with the shifting wind directions typical of urban areas. These new wind turbines are omni-directional and come in sizes appropriate for individual homes and larger buildings. As such, wind turbines are increasingly a part of sustainable green buildings.
"Green" buildings can be built from a variety of new eco-friendly building materials. This includes what is perhaps the most common form of new building material -- insulated concrete forms (i.e. ICF) - as well as more exotic new building materials such insulation made from recycled jeans or recycled newspapers to replace the traditional fiberglass insulation used in homes or renewable bamboo wood floors.
Geothermal heating and cooling involves the use of ground source heat pumps to take advantage of the fairly constant ground temperature to reduce the cost of normal heat pumps to provide for heating and cooling. Wells are dug to a depth of typically 200 feet to obtain a source of air that is approximately 55 degrees year around. This reduces the need for cooling the outside air for air conditioning in the summer and for heating the outside air in the winter, and thus provides for a more efficient form of heating and air conditioning of buildings.
Another method of sustainable green building design is to incorporate means of natural ventilation and lighting into a building, and thus reduce the need for energy use. Innovative new methods of accomplishing this are solar tubes mounted on the roof of buildings that bring concentrated sunlight into buildings and often replace the need for daylight lighting within the building. Also, buildings are increasingly being built with vents on the roof that can be opened to suck the hot air out of buildings and with windows that open that can draw fresh air into buildings.
A new method of green building design is to produce a biofuel at your own home. Previously, biofuels had to be made at a larger biofuel processing facility such as a corn to ethanol plant. While some individuals had converted their automobiles to run on collected cooking grease, previously there were not commercially available biofuel processing units sized for domestic use. Recently, however, this has changed with a number of companies selling domestically sized biofuel conversion units. Above is a photo of such a domestic biofuel conversion unit to illustrate how compact in size they can be. Also, scientists are experimenting with such novel ways as growing a biofuel in vertical algae tanks. As a consequence, it is now possible to build sustainable green buildings that include units to produce biofuel - so one does not have to drive to the gas station to fill up one's automobile!
One example of a proposed sustainable "green" building is the Ecolaboratory building to be built on the 7,200 square foot P-patch in the Belltown neighborhood of downtown Seattle. Conceived by Weber Thompson, it is proposed that the main living units of the building be constructed of recycled shipping containers. All water, including black and gray water, is to be recycled for the use of residents and landscaping water needs. Residents will be able to individually control the amount of their natural ventilation by the design of what are referred to as "earth tubes." Solar hot waters panels will provide for the heating of hot water. Also providing energy for the building will be photovoltaic solar panels, biomass conversion, and even hydrogen fuel cells - to generate electricity.
To demonstrate how a sustainable home can be constructed, Duke University in conjunction with Home Depot has built a sustainable "smart home" demonstration. It has received a LEED (Leadership in Energy and Environmental Design) platinum rating, the highest level rating. It includes solar water panels for hot water heating, 18 photovoltaic solar panels that generate 3 kW of electricity, a vegetated green roof planted with sedums that are drought tolerant and capture and filter rainwater while providing roof insulation, rainwater collection for irrigation of the grass of the site, Energy Star appliances, and recycling of construction waste materials.
An example of a sustainable green building that takes advantage of natural ventilation is the Environmental Nature Center in Orange County, California.
Sunday, May 3, 2009
The proposed Independence Station building claims that, when constructed, it will be the highest rated Platinum LEED (Leadership in Energy and Environmental Design) building in the world. It will include almost all of the various approaches to green building design (green roof, photovoltaic solar panels to generate electricity, passive solar hot water heating, geothermal heating and cooling, rainwater harvesting, etc.)
The Clinton Presidential Library in Little Rock, Arkansas is the first presidential library to be designed green. When it opened, it received a silver LEED (Leadership in Energy and Environmental Design) award, but has since been upgraded to the highest award level -- i.e. a platinum award. It has a green roof with approximately 90 different types of plants, solar panels, and includes a wetlands next to it that is protected as part of the library.
One of the best examples of a building design with a green roof is the "living roof" of the newly constructed California Academy of Science in San Francisco.
The BedZED Eco-Village located in Wallington, South London, England is intended to be a zero-energy, carbon neutral community development. Opened since 2002, it is designed to house 100 families, community facilities, and office space for 100 workers. Developed by Peabody Trust in conjunction with Bioregional Development Corporation and designed by architect Bill Dunster, its homes are designed to use only 10 percent of the energy of a typical home.
The Brighton Earthship is an experimental sustainable building near Stamner Park, Brighton, East Sussex, England. Its walls are made from recycled tires and it is built semi-underground to use the insulation properties of the earth itself. It includes a windmill and passive and active solar heating, as well as geothermal heating and cooling.
Tuesday, April 21, 2009
Gish Apartments in San Jose, CA are one of the few affordable multifamily apartment buildings to be constructed as a green building. They were constructed with solar photovoltaic panels on the roof, with residents receiving 30 percent of their electricity from these panels. Stormwater runoff was reduced by locating all parking underground and landscaping the grounds with drought tolerant plants as opposed to grass. The site itself is a cleaned-up "brownfields" site, and thus is a good example of land recycling and reclamation. The building is located near public transit with all tenants receiving free EcoPasses entitling them to unlimited free transportation on the city's buses and light-rail system.
One way to reduce energy usage and to make our urban environments more sustainable is to construct our buildings with more energy-efficent materials. This includes better insulation for our homes and using new types of glass to regulate the amount of light allowed into buildings based upon the season of the year. For the construction of the swimming stadium for the Beijing Olympics, this same concept of regulating the amount of sunlight allowed into the building was used - but instead of glass, the exterior of the building was constructed of a special plastic "bubble-wrap" that could be electronically controlled so as to allow or restrict light into the building.
Another approach to making buildings more energy efficient is to install wind turbines on them to generate electricity. The most radical example of such wind turbines installed on buildings is for a building recently built in Bahrain as shown above.
To see more examples of green buildings, one can watch the television show "World's Greenest Buildings" on the cable station Planet Green (part of Discovery Channel). One can also go to the non-profit U.S. Green Building Council's web site at http://www.usgbc.org/ to learn more about its LEED (Leadership in Energy and Environmental Design) rating system for green buildings.
"NEW URBANISM" -- Green building design does not have to focus on individual buildings. Instead, another approach to green building design - is to include homes, commercial, retail and civil buildings into a comprehensive green design. Today, this is typically referred to as "new urbanism" or "neo-traditional" design. The intent is to reduce the carbon footprint of all the buildings by making the entire community more walkable, including more green parks to absorb carbon and heat and to provide cooling in the summer, and to reduce the need for gas consuming automobiles by linking the community to the larger city by mass transit. This intentional green design of an entire community was first implemented in the 1920's when landscape architect John Nolen designed a new suburb on the outskirts of Cincinnati, Ohio. This new suburb was named Mariemont and was meant to be a "National Examplar" of how suburbs should be designed. It was connected to Cincinnati by streetcar and by Route 50 which ran through its center. As such, it was the first transit-oriented suburb. It also was designed with all the schools and town center to be within a five or ten minute walk from all parts of the community. As such, it was designed to be promote walking and bicycling. To make the community even more pedestrian-friendly, numerous small to medium sized parks were scattered evenly throughout the community, park benches were built on street corners, streets were designed to be narrower than the typical modern suburban street to slow traffic, and large shade trees were planted between the sidewalks and streets to provide shade for pedestrians. Also, the garages of homes were set even with or behind the homes acccessed by alleyways. Through his planning of Mariemont and other subsequent communities and cities, John Nolen is credited with being the "father of modern urban planning." Ironically, the demand for housing after World War II caused the nation to abandon the planning model of John Nolen and instead to develop sprawling residential only suburbs in the model of Levittown, New York. These newer suburbs were designed for the automobile as opposed to pedestrians or mass-transit. They also abandoned the concept of integrated mixed-use as John Nolen had designed for his Mariemont community. Today, however, the 1950's style of suburban sprawl after the model of Levittown is understood to be energy efficent, wasteful of land, a contributor to air pollution and global warming, destructive of the natural environment, and destructive of of the sense of community. For this reason, urban planners and designers are increasingly turning back to the model of Mariemont as designed by John Nolen. When employed in for a suburban development, this model is typically referred to as "New Urbanism." When employed in the design of a closer-in and more dense semi-urban development, this model is typically referred to as "Smart Growth." In fact, both emphasis the same principles emphasized by John Nolen -- i.e. pedestrian oriented, transit-based, mixed-use development, with the purpose of both being to make urban and suburban development more sustainable and compatible with both the human and natural environment (as opposed to emphasizing the automobile). These two models for land development and zoning have become the primary methods of urban planners to make urban land use more sustainable. One of the first examples of "New Urbanism" is the community of Kentlands in Gaithersburg, Maryland -- while two of the more recent and best examples are Celebration in Orlando, Florida and the King Farm in Rockville, Maryland (with the latter being initially designed by Richard Hopper, who is referred to above as having initiated the concept of sustainable design in urban planning and development back in the 1970's and who then went on to also become one of the pioneers in promoting recycling and resource recovery). With respect to the concept of Smart Growth, perhaps the best known example of efforts at "Smart Growth" is Montgomery County, Maryland (with the King Farm referred to above being part of Montgomery County, Maryland's efforts to promote "Smart Growth").
Above is a site plan for the "New Urbanism" community of the King Farm in Rockville, Maryland (click on picture to see a larger version). The gray colored line running through its middle from left to right is a road where the center right-of-way is reserved for light rail, to connect the subway to the right where the road runs also runs into Rockville Pike. Until the light-rail is built, the center right of way is being used for a special bus to take residents to the subway, which then goes to downtown Washington, D.C. The King Farm is a mixed-use development with a town center and schools that consists of 3,200 residential units and 3.2 million square feet of office space. It has received numerous national awards for its "New Urbanism" design.
Above is a site plan for the "National Examplar" community of town of Mariemont on the outskirts of Cincinnati, Ohio and designed by John Nolen in the 1920's. It is credited with being the first "new urbanism" or "smart growth" community in the U.S. New urbanism is also sometimes referred to as neo-traditional design.
Above is a photograph of the Mariemont town square. It is interesting to note how similar the Mariemont town square, which was designed in the 1920's, is to the more recently town square for the new urbanism community of Celebration built by Disney in Orlando, Florida.
Monday, April 20, 2009
Above is a photograph of the non-denominational community church in Mariemont. It was the first building completed in Mariemont, with its slate stone roof come from a 1200's English abbey barn. As such, one could say that Mariemont Community Church is the oldest church in the U.S. Across from the park in front of the church (which also contains a fountain, but larger than the one in the main town square) is the original town square that was only two blocks away from the street-car line. Just to the left of the church is the Dale Park Elementary School and one block further up is the Mariemont Community Center and the High School. The back of the Mariemont Community Church slopes down to Route 50, which is a gently curving divided highway through Mariemont. On the other side of Route 50 from the Mariemont Community Church is a boat house and small lagoon where one could originally take out a rowboat or go ice skating in the winter. Just beyond the boat house is Dogwood Park which contains the large bell carillon in southern Ohio.
Above is a photograph of some of the affordable English-style garden apartments built in Mariemont to provide a wide range of housing types and cost. Each has a lawn in front and a backyard that fronts on an alley. Across the alley is a garage designed like an English-style carriage house for each apartment. In the center of the square of garages is a playground.
Above is a photograph of a typical residential street in Mariemont - designed to encourage walking and bicycling and to slow automobile traffic. Note the large shade streets planted between the sidewalks and the street. Also, unlike most modern suburbs where hedges and picketed fences in the front yard are typically prohibited, the homes in Mariemont all have uniquely landscaped front yards. Finally, unlike most modern suburban homes where the garage juts out in front and is the dominating feature of the home facing the street, in Mariemont the homes were designed with their garages either parallel or set back further than the home so as to not stand out.
As going "green" and the building of sustainable communities becomes more and more popular, there are increasing number of "model" sustainable eco-communities. Above is a picture of such a proposed new sustainable city for 77,000 people in Korea. Meanwhie, below are descriptions of actual sustainable model eco-communities already built or now in the process or being built. These include the city of Greensburg in Kansas, the university campus for Denison University in Ohio, the island of Samso in Denmark, and Masdar City as part of Abu Dhabi (the capital of the United Arab Emirates).
After being devasted by a tornado, the town of Greensburg, Kansas decided to rebuild itself with all of its public buildings being LEED (Leadership in Energy and Environmental Design) Platinum rated. It's first public building designed to this center, i.e. the Greensburg Arts Center, is the first platinum rated green building in Kansas. Designed by the non-profit Studio 804 of the University of Kansas, it is built with special tempered glass that blocks UV rays, 4 inch concrete floors that help retain the heat in the winter, skylights to allow in natural daylight, a green roof planted with the succulent plant sedum to absorb UV rays and reduce the need for air-conditioning in the summer (while the soil medium helps insulate and reduce the need for heating in the winter), cellulose insulation made by recycled newspapers, and both 3 Kestrel wind turbines that produce 600 watts of electricity and photovoltaic solar panels on the roof that all are used to provide electricity to the building. A converter in the basement converts the DC electricity to AC electricity, and what electricity that is not used is either stored in 12 batteries or is sold as excess to the city. The building also has 3 geothermal heating and cooling wells that draw 55 degree temperature air from 200 feet deep that makes the heat pumps of the building more efficient in both the winter and summer. Finally, rainwater from the building is collected in a 1500 gallon cistern and is used to water the natural buffalo grass lawn. The City of Greensburg has been featured in a series shown on the television station Planet Green to demonstrate what has been accomplished by one community's commitment to a more sustainable future.
Denison University in the town of Granville near Columbus, Ohio - famous for being one of the best small liberal arts colleges in the U.S. - has committed itself to be a sustainable university community. Above is a picture of the green renovations being made to Cleveland Hall. Once completed, Cleveland Hall will be an LEED rated building. Denison has also installed solar panels on its library, instituted a university recycling program, instituted a university composting program, established a program of environmental studies, and has research grants available to undergraduate students who want to pursue research projects in sustainability.
The island community of Samso in Denmark has become the first carbon-neutral community in the world. To make itself a zero-energy model community, the citizens of Samso built 11 onshore and 10 offshore wind turbines. Also, 70 percent of the homes have been converted so that heating is provide by biofuels or solar. As a result, not only has Samso been able to make it self a carbon-neutral, zero-energy community, but it produces surplus electricity that it sells to the mainland of Denmarks. All of this was done by the community itself with all investment paid for by the local citizens without any help from outside sources.
Dongtan is an undeveloped island just offshore of Shanghai at the mouth of the Yangtze River that is about the size of Manhattan in New York City. The government of Shanghai proposes to develop it as a model sustainable community. It will be developed along a public transit corridor once a subway and bridge and tunnel are constructed to link it with the main part of the city of Shanghai. More than half of the island, however, will be maintained as farms and parkland. Hollowed out hills will be constructed to provide for underground organic farming while a power plant will be built to burn waste rice hulls to provide heating to the buildings and homes on the island. Delivery trucks will be banned on the island, and be required to transfer their goods to non-emission vehicles to transport goods on the island. Finally, a wind farm will be constructed on the island to provide electricity.
Babcock Ranch on the Gulf coast of Florida is proposed to be a sustainable, solar-powerd community/city. Consisting of 17,000 acres, it will eventually accommodate 19,500 homes and 6 million square feet of commercial space that will employee 20,000 individuals. The exciting aspect of the proposed development, however, is a proposed 75 MW solar photovoltaic power plant to be built by Florida Power & Light.