Picturing the Hidden Environmental Benefits of Passive Building Design Decisions

Every design decision an architect makes carries with it a hidden environmental cost. Architects are concerned about issues like sustainability, greenhouse gas production, and other environmental costs, but there is little they can do until there is an easy way to visualize exactly what these costs look like. This paper describes a user-friendly microcomputer design tool that calculates the environmental costs of each architectural design decision, and then displays an easy-tounderstand picture of how these costs change from one design to the next. This new version of SOLAR-5 shows how a well designed passive building produces less air pollution and greenhouse gasses, and thus how it contributes to a more sustainable environment. Seven different atmospheric pollutants are included in the database, measured in pounds of pollution per KwHr for electric power generated and per MMBTU of natural gas or heating oil burned. SOLAR-5 also displays the amount of energy a building uses and its cost of operation. This new design tool can show that good passive buildings not only conserve energy, but also account for hidden environmental benefits. If we are to build a sustainable future for this planet, architects need easy-to-use design tools like this to help them visualize the many environmental consequences of their design decisions. _______________________ BENEFITS OF PASSIVE DESIGN Every decision an architect makes has an impact on the environment. For example, changing the orientation of a window, or the color of the roof, or adding a suncontrol will change the amount of heating fuel the building uses and the amount of electricity it uses for lighting and air conditioning. Buildings use about 35% of all the energy consumed in this country. Virtually every decision that architects, builders, and homeowners make about the design and operation of their buildings carries with it an energy cost, and all energy costs in turn have environmental costs. The recent International Earth Summit in Rio demonstrated that it is the First World, not the Third World, that is responsible for the most serious threats to the global environment. Susan Maxman, then President of the American Institute of Architects and a delegate to the Rio conference, argued that architects must take a leadership role in solving these environmental issues. Since Rio, "sustainability" has become an increasingly popular topic, which shows why it is so important that architects are able to say whether each design decision they make will have a positive or negative impact. To take on this leadership role architects need easy-to-use design tools that show the environmental consequences of different building design and operating decisions. To implement the Rio climate treaty, diplomats meeting in Berlin in 1995 reached an agreement that for the first time committed the United States to actually reducing emissions of carbon dioxide. As a result, when the "Kyoto Protocol" is formally signed in Japan in 1997, our government will have to face some hard choices, such as raising energy taxes, reducing fossil fuel subsidies, or increasing incentives for energy efficient new building designs and retrofit. The U.S Department of Energy estimates that by the year 2010, if we do not take serious action, buildings in this country will consume 38.5 quadrillion BTUs (quads) of energy annually. However, economically achievable conservation measures can reduce this total by 30% (saving 11.2 quads), while technologically feasible measures can reduce the total by an incredible 45% (saving 17.8 quads). As a rough rule of thumb, 100,000 BTUs costs about one dollar, thus each quad costs ten billion dollars out of pocket. This means that implementing only the economically feasible conservation measures could save U.S. energy consumers $112,000,000,000 every year. This new design tool shows architects how much each of their clients will save of this total. While the economics of building design decisions have direct and tangible impact on the people who use the spaces, the owners who pay the bills, and the utilities companies who sell the energy, they have no direct financial impact on the rest of us. On the other hand, the environmental consequences of building energy design decisions effect every living thing on the planet. Thus, there are serious measurable costs to our shared environment for each square foot of building that is inefficiently heated, cooled, lighted, or even needlessly built in the first place.