Designing and Detailing for Extension of Useful Building Life

The environmental impact of materials is central to their selection once baselines of performance are met. Even materials with large carbon footprints, such as concrete, can be defensible choices once the timeframe of those... [ view full abstract ]

The environmental impact of materials is central to their selection once baselines of performance are met. Even materials with large carbon footprints, such as concrete, can be defensible choices once the timeframe of those impacts are amortized over extended timeframes of beneficial use. Historically, the design life of select buildings have extended to centuries, and many continue to provide beneficial use. However, the trend has been toward shorter and shorter building lives. Many institutional buildings are projected to only provide 50 years of service under conditions of continuous, heavy use.

This trend can be contravened through strategies both global and micro. Global in the sense of siting and orientation to acknowledge and accept the flows and fluxes of energy in the environment, as well as recognition of the evolution of philosophies of human use of spaces within and between buildings over decades. Building systems age and performance of newer systems eclipse them. Eventually, they must be updated or replaced, contributing in many cases to reductions in the useful life of buildings. Snapshot pro forma evaluate costs versus benefits, typically following change in ownership or administration, during a building's life. Its continued existence becomes the question which must be addressed. In the face of such inevitable milestones, design with all these macro factors in mind can extend the useful life of buildings.

On the micro scale, the detailing of materials to accept energy from the environment and release it in a way that accommodates the resulting changes in the materials themselves will extend their useful lives. Both incorporating maintenance access and minimizing the need for it by avoiding the selection of materials that lose performance due to off-gassing, corrosion, and a myriad of other considerations is important. Weathering and infiltration are ongoing concerns. The goal is to double, triple, or quadruple the useful life of buildings, thereby spreading material impacts over time. As long as the calculus driving building replacement decisions can be forestalled through considered design and detailing, the embodied energy in buildings will not be lost, and the benefits they provide will be allowed to continue to accrue to their users, society at large, and the environment.