Zero Net Impact

Building green always comes back to the issue of reducing our impact on the environment and on our health. Today's most widely adopted green building standards cut energy and water use by a third, while creating more durable, comfortable, and healthy homes. At the same time, leading architects and developers have achieved even greater levels of sustainability--by developing buildings and neighborhoods that power themselves and harvest their own water, for example. A new generation of green developments aims to take sustainability beyond buildings by helping residents reduce their car use and improve their food purchasing habits.

Efficiency plus renewables

Residential neighborhood-scale developments near London BedZED and in Victoria, British Columbiab Dockside Green combine extremely energy efficient design with renewable energy generation onsite. A similar approach is feasible in the Washington, D.C. area, and sustainable development nonprofit One Planet Living is working with developers to build sustainably at the Southwest Waterfront. In fact, a number of houses and businesses in D.C. already use photovoltaic panels to spin their electric meters backwards.

These model developments take key features of green design--solar orientation, thermal mass, superb insulation, natural ventilation, and high performance glazing--to the next level. When combined with highly space efficient design and a site that allows for optimal solar orientation, energy savings take leaps and bounds. Space heating and cooling loads drop dramatically, to the point where a neighborhood scale "waste to energy" unit can meet the heat and power needs of the entire London-area development mentioned above. These model developments are demonstrating the kinds of advancements that we need to effectively address global warming.

Zero carbon through sustainable living

Even when a building's embodied energy - the energy used to produce, transport, and assemble its parts - is cut by 30 percent through resource efficient construction and local materials sourcing, a green home can only address about 50 percent of a person's carbon footprint. That other 50 percent lies mostly in food purchases, transportation, and waste. In another sense, green homes cannot provide sustainable living without efficient connections to the larger community: friends, family, work, and retail.

Sustainable neighborhoods are about more than just the buildings located within them. They are about communities where residents can leave behind their cars and walk, bike, and take public transit to nearby schools, grocery stores and other key services. Sustainable neighborhoods not only incorporate homes that have space for offices but also encourage car sharing and carpooling.

Mimicking nature: water and waste

An innovative development in Los Angeles is integrating distributed rainwater storage systems into all of its lots. Cisterns, tree plantings, permeable pavement, and other features will turn the neighborhood into the equivalent of a built forest. Although initial costs are high, the greatly-reduced impacts on municipal infrastructure have secured broadly based government funding. Read more.

Nature also recycles all of its waste. Leading sustainable developments aim for zero waste by reusing and recycling construction debris--90 percent or more in most cases--and integrating recycling and composting systems into the homes. This also reduces residents' carbon footprints. Additionally, some developers are considering using sewage to fuel anaerobic digesters that generate electricity. Others give back to nature by constructing wetlands to treat sewage and provide new wildlife habitat.