GREEN BUILDINGS - A new approach to building sustainable urban environments are green buildings. Actually, this is an approach that might have been utilized to help cool one of the first cities in ancient times -- i.e. the hanging gardens of Babylon. Green buildings help reduce the "heat island effect" created by all the concrete of our urban areas that cause cities to be hotter than the surrounding area. This, in return, reduces the need for air-conditioning and energy usage. Green buildings also can help to absorb carbon dioxide from the air. Both can help reduce global warming. In this regard, there are several approaches to designing green buildings. One is to hang vegetation from the side of buildings. This is a particular attractive way to design parking garages to be more eco-friendly. For existing buildings, however, the preferred approach is to build green roofs. Not only can such green roofs reduce the heat of urban areas, but they also can catch and filter rain runoff, thus reducing the contaminated stormwater runoff that otherwise flows into our rivers and bays. In this regard, on Earth Day of 2009, the City of New York announced incentives and regulations to actually require the conversion of buildings to green roofs where there can be shown to be an economic benefit. Chicago is another city to aggressively promote the conversion of buildings to green roofs. What makes green roofs attractive today are new plastic membranes that are laid on the roof to collect the rain water run-off. A special soil is then put on top of the membrane in which plants are grown. The plants in turn absorb much of the rain water, thus reducing the stormwater runoff produced from the building. Above is an example of a green building built recently in Fukuoda, Japan.

Another variation on a green building is known as "vertical farming." This is a new concept to build high-rise farms (i.e. food grown in specially designed high-rise buildings) so as to reduce the transportation costs of bring food from the countryside to cities. In the proposed building shown above, wind turbines are installed on top of the building to provide energy for the building. Instead of growing the plants in soil, the proposal is to grown the plants using aeroponics. This is an approach where plants are hung in the air and a fine spray containing water and nutrients is sprayed on the roots of the hanging plants. The proposal is to collect rainwater and to store it in water tanks to supply the water. After spraying the roots of the plants, the excess water is then collected and re-used.

SOLAR BUILDINGS - Another approach to the design of sustainable buildings is to install on buildings either passive solar systems to produce hot water or solar photovoltaic panels to produce electricity. Above is a photograph of the K2 sustainable apartments in Windsor, Victoria, Australia that are built with not only both passive solar and solar photovoltaic systems, but also are made of recycled materials and include rainwater collection on the roofs.

NEW ENERGY-EFFICIENT BUILDING MATERIALS -- Most individuals do not realize that the heating and air-conditioning of our buildings accounts for over 50 percent of all our energy usage. One way to reduce such 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.

INSTALLATION OF WIND TURBINES ON BUILDINGS -- 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. Meanwhile, a new innovative type of wind turbine for buildings has been invented by Bil Becker of Chicago who has designed a special type of DNA shaped wind turbines to deal with the variable direction of the wind on top of buildings. His wind turbines are being tested on several buildings in downtown Chicago.

MASS TRANSIT -- Next to the energy used to heat and cool buildings, the greatest amount of energy we used is in transportation. As such, any sustainable design and planning of our urban communities needs to incorporate the use of mass transit and other innovative forms of energy efficient transportation as they are invented. In this regard, we need to be careful that our zoning and building codes do not lock us into outdated technology. As an example, today buildings and mass transit are designed separately. As a consequence, it is often a long walk outdoors to access mass transit, thus discouraging the use of mass transit. What is even worse is that too often mass transit stations are only accessed by driving to them by automobile and parking. A better design would be to allow residential and commercial use all within walking distance of transit stations, and to construct major civic and other buildings where mass transit is immediately adjacent or connected to the buildings. Also, if we want to encourage mass transit, we need to find better ways to accommodate the needs of the disabled so that mass transit is available to all. Finally, in today's "information age" we need to find a better way to use information and smart technologies to better manage traffic flow so as to help the wasted energy of individuals sitting in congestion.

Example of light-rail mass transit.