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Source section: Section 2 - Sustainable Thinking PDF page: 36 Guide page: 29 OCR quality: high (479 words)
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the processes and associated inputs (energy, water, materials) and outputs (wastes, by-products), from the extraction and processing of raw materials and recycled feedstocks, the transportation of these materials, and the manufacturing and packaging of the product to its use, maintenance, and finally its recycling or disposal. These inputs and outputs are quantified and their effects on the environment and human health are measured. Although LCA does not address all potential effects, it provides a comprehensive picture of the life-cycle. This information can then be used to support decision making. Tools and databases used in conducting LCAs are available from sources in the U.S. government and the private sector. Life-cycle costing looks at both purchase and operating costs as well as relative savings over the life of the building or product. It calculates payback periods for first costs, providing a context for making decisions about initial investments. For example, more efficient mechanical systems generally cost more than inefficient equipment, but by looking beyond the purchase price and calculating all the energy, maintenance, replacement, and other costs over the life-cycle of the equipment, we can better understand the true cost of the equipment—both to the environment and to the building owner. LCC can be used in comparing alternatives with different initial and operating costs. For a building this usually includes the following costs: ¢ Initial purchase, acquisition, or construction ° Fuel
- Operation, maintenance, and repair
- Replacement
- Disposal (or residual value for resale or salvage) ¢ Finance charges
- Other intangible benefits or costs, such as increased employee productivity Life-cycle thinking can be applied to all decisions in green building, not just products and buildings. Teams need to look for opportunities to evaluate the environmental impacts of design decisions and improve sustainability at all points in the project’s life-cycle. Once decisions have been made at each phase, however, those opportunities can become limited. The key to sustainability is to establish goals and targets early in the process, understand the systems that are in play, and anticipate how those systems are likely to change and evolve. Land-use and urban planners also draw on the concept of life-cycles because decisions about the location of roads and infrastructure can affect all future decisions about that land for centuries. Consider again the example from Section 1 of Rome’s road structure: these roads were built for pedestrians and therefore remain walkable and pedestrian oriented even today. This does not mean that there are no opportunities to make vehicle-oriented development greener, but it does mean that the challenges of reducing transportation impacts, such as carbon footprint, are greater in projects where pedestrian access is not an initial goal. With future implications of the built environment in mind, we must rethink the processes we use at all phases of the life-cycle. Assembling the right team, establishing goals, and understanding the systems and metrics for success will help ensure that we move closer to a sustainable built environment. N 6 q un 29