Zero Energy Architecture

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Buildings account for 40 to 50 percent of all energy consumption and, in the United States, buildings produce more greenhouse gases than cars. One goal of environmental engineering is to develop new houses, offices, or manufacturing plants that minimize the amount of energy they use. A zero energy structure takes this goal a step further by not only minimizing energy use but by using no net energy at all in its operation. A zero energy building produces all the energy it needs to operate and requires no additional energy sources. A new discipline called zero energy architecture seeks to create zero energy homes, offices, museums, nature centers, and classrooms. When buildings have no need to draw energy from a utility, such as an electric company, the buildings are said to be zeroing
out energy consumption or running off the grid. Put simply, zero energy architecture creates buildings that add up to zero on their ecological balance sheet.

Zero energy houses differ widely in style because they conform to local geography. Regardless of location, zero energy buildings have many of the following features in common:

• self-sufficient energy production
• emphasis on passive energy systems
• strategically placed shade trees for cooling
• added insulation from ivy and other plants surrounding the house
• south-facing windows to capture sunlight and heat
• skylights for natural lighting
• cross-ventilation from open windows and skylights

The Croatian-born architect Zoka Zola has built a zero energy house three miles (4.8 km) from the downtown Loop area in Chicago, Illinois. The house, completed in 2002, uses all of the features in the preceding list with two additions: (1) on-site solar, geothermal, and wind energy production, and (2) a green roof covered in growing foliage that absorbs rainwater and provides insulation. Said Zola in 2007 in an online video tour of the house, “The house is designed for two people to be a zero energy house, meaning zero fossil fuel consumption while the house is running.” Similar zero energy houses have been built since then, but they remain relatively rare in U.S. communities.

An intangible benefit comes from ecological design and zero energy architecture: a new appreciation of nature for people who occupy ecodesign buildings. People living in ecologically designed buildings begin to understand the benefits of natural lighting, ventilation, and water flow. In time, eco-design may lead people to change their behavior regarding conservation.

Zero energy concepts have branched out from single homes to entire communities, such as London, England’s Beddington Zero-Energy Development (BedZED). Completed in 2000, BedZED contains more than 80 homes and businesses that form a carbon neutral community, meaning its operations put no net carbon into the atmosphere—the community
absorbs as much or more carbon than it emits. BedZED accomplishes this by using the following main features:

• structural materials that store heat in winter and release heat in hot summers
• all buildings enclosed in 12 inches (30 cm) insulation jacket
• south-facing terraces to maximize heat-gaining exposure to the Sun
• north-facing offices to minimize Sun’s heat that might be wasted
• emphasis on roof gardens, solar energy, sunlight, and wastewater recycling
• emphasis on interiors made of sustainable, recycled, or reclaimed materials
• capture of heat generated by occupants’ activities, such as cooking
• meters in each room to help residents monitor their electricity use

Zero energy architecture requires even more commitment to energy savings than less strict ecological design. The concepts of zero energy design can be useful, however, as a model for conservation and sustainability in ordinary communities.