There is reasonably widespread knowledge of the recent trend of large scale building envelope failures in North America. These failures are common in the Pacific coastal regions, but are also occurring in Atlantic coastal and interior regions of Canada and the United States. There have been numerous studies completed on the causal factors of these failures with some understanding of the financial consequences, but there has been little written about the environmental effects associated with these failures.

One important environmental effect associated with building envelope failures is the consequence of increased material use. Materials that fail to achieve a reasonable service life represent increased environmental effects associated with the production of new replacement materials. The environmental effects associated with the production, use, and disposal of materials are known as the embodied environmental effects of materials. Large-scale building envelope failures represent significant impacts to the environment due to these embodied material effects.

This paper will present a methodology to determine the environmental material effects associated with building envelope failures. The methodology will be demonstrated through two case studies in Ottawa, Ontario Canada. The case studies will involve one high-rise building and one low-rise building complex, and are based on real projects in recent years.

Embodied environmental material impacts were estimated using ATHENA’s Environmental Impact Estimator software. The ATHENA software is an internationally recognized tool for obtaining comprehensive and reliable environmental life cycle burdens of buildings. It covers building material and system life cycle stages from the “cradle” (natural resource extraction or recycling facility) through to its “end-of-life” (grave). For this paper, results reporting of material effects will include aggregate ecologically weighted resource requirements, embodied energy, global warming potential, an index of air and water pollution effects, and solid wastes as indicators of environmental burden.

Presented at Thermal Performance of Exterior Envelopes of Whole Buildings X – December 2007

Units: Dual