GEF

Unit 9  |  New Technology and Innovative Sustainability Approaches 202 Energy efficiency and conservation are central components of green building. Buildings that maximize energy conservation offer significant sustainability and economic benefits. In passive house design , builders incorporate superinsulation , high-per- formance windows, and passive solar design principles that take advantage of the sun’s energy for heat and light. Heating, venti- lation, and air conditioning ( HVAC ) accounts for 30 percent or more of a building’s total energy use. Using building-integrated heating or cooling components instead of forced air significantly reduces energy requirements. Other green designs incorporate landscaping, vertical plantings, or green roofs that protect buildings fromwide temperature swings. Rooftop solar thermal collectors heat water using the energy of the sun, while photovoltaic panels produce electricity from sunlight. Recently, building-integrated photovoltaics , electricity-generating components built into roof shingles, windows, or other materials, have become more prominent in building construction. Although cost reductions have made this technology more affordable, solar electric systems still represent a high initial investment to building owners. National and local governments in many countries provide subsidies and tax credits to owners that offset some of these costs. Buildings that are connected to electricity grids can, in most countries, sell excess power to utilities, in effect making them small-scale power plants and providing a reliable income source to owners. Many green buildings use solar power to heat water. PASSIVE HOUSE DESIGN A set of building design standards that radically reduce energy use over conventional structures. SUPERINSULATION An approach to building design and construction that uses high amounts of insulation to minimize energy demands. HVAC Heating, ventilation, and air conditioning, which are important components of building sustainability. GREEN ROOFS Building roofs that are covered with vegetation, providing insulation, absorb- ing rainwater, and providing wildlife habitat. SOLAR THERMAL COLLECTORS Components that collect the sun’s heat for heating water. BUILDING-INTEGRATED PHOTOVOLTAICS Electricity-producing solar components that are built into building materials.