Since the early 1990s, sustainability has become an increasing priority for facilities projects. It is no secret that building construction and operation have an enormous direct and indirect impact on the environment in terms of energy use, atmospheric emissions, use of raw materials, waste generation, water use, and many other factors. As economy and population continue to expand, the design, construction and operation community will face increasing challenges to meet the new demands for facilities that are accessible, secure, healthy, and productive while minimizing their impact on the environment.
Figure 1. Source: Levin, H. (1997) Systematic Evaluation and Assessment of Building Environmental Performance (SEABEP), paper for presentation to "Buildings and Environment", Paris, 9-12 June, 1997.
For the design, construction and operation of a facility, there is an especially important interface between the indoor and outdoor environments, that of the building envelope. The building envelope is comprised of the outer elements of a building—foundations, walls, roof, windows, doors and floors. The prime functions of the building envelope are to provide shelter, security, solar and thermal control, moisture control, indoor air quality control, access to daylight, and views to outside, fire resistance, acoustics, cost effectiveness and aesthetics. Because of the varied and sometimes competing functions associated with the building envelope, an integrated, synergistic approach considering all phases of the facility life cycle is warranted. This "sustainable" approach supports an increased commitment to environmental stewardship and conservation, and results in an optimal balance of cost, environmental, societal, and human benefits while meeting the mission and function of the intended facility.