No abstract

Various green building rating systems (GBRSs) have been proposed to reduce the environmental impact of buildings. However, these GBRSs, such as Leadership in Energy and Environmental Design (LEED) v4, are primarily oriented toward a building's use stage energy consumption. Their application in contexts involving a high share of renewable energy, and hence a low-impact electricity mix, can result in undesirable side effects. This paper aims to investigate such effects, based on an existing office building in Quebec (Canada), where more than 95% of the electricity consumption mix is renewable. This paper compares the material impacts from a low-energy context building to material considerations in LEED v4. In addition to their contributions to the building impacts, material impacts are also defined by their potential to change impacts with different material configurations. Life cycle assessment (LCA) impacts were evaluated using Simapro 8.2, the ecoinvent 3.1 database, and the IMPACT 2002+ method. The building LCA results indicated higher environmental impact contributions from materials (>50%) compared to those from energy consumption. This is in contrast with the LEED v4 rating system, as it did not seem to be as effective in capturing such effects. The conclusions drawn from this work will help stakeholders from the buildings sector to have a better understanding of building environmental profiles, and the limitations of LEED v4 in contexts involving a low-impact energy mix. In addition, this critical assessment can be used to further improve the LEED certification system. Keywords:building certification industrial ecology leadership in energy and environmental design (LEED) life cycle assessment (LCA) structure and envelope materials Supporting information is linked to this article on the JIE website Conflict of interest statement: The authors have no conflict to declare.

Design of light-frame wood wall assemblies should consider several performance criteria. Possible alternatives must respect minimum code requirements for the studied context. Then, additional performance characteristics may be considered to achieve the most suitable configuration for a specific project. It is, however, not simple to define how several performance criteria can be evaluated simultaneously and which scale should be used to compare assemblies. Existing tools to evaluate performance criteria consider mostly one parameter at the time. An evaluation methodology taking into account at once different performance characteristics would be beneficial in the decision process. With the final aim of developing a multi-criteria framework to support the evaluation of improved factorybuilt wood-frame exterior walls, this article presents a methodology for quantitative evaluation of a set of performance characteristics. The identification of appropriate criteria is followed by the choice of quantification mechanisms. A case study comparing five wall assemblies exemplifies this methodology.

Designers of light-frame wood wall assemblies should consider several performance criteria simultaneously in addition to minimum requirements set by building codes. Evaluation of various performance characteristics can help select the most suitable configuration for a given project in a given context. In a previous article, we identified appropriate criteria and explored their means of evaluation. Following up, this article integrates the context and the preference of the decision-maker and seeks to obtain a ranking of the various alternatives using quantitative and qualitative information. Four multicriteria decision analysis (MCDA) techniques are explored: weighted sum, MACBETH, ELECTRE II, and PROMETHEE. The approach is applied to a case study where five wall assemblies are compared within six different decision contexts. It shows how the choice of the appropriate aggregation method depends on the nature of the performance evaluation scales and demonstrates the usefulness of MCDA to consider simultaneously different aspects of wall performance.