Do resilient and sustainable design strategies conflict in commercial buildings? A critical analysis of existing resilient building frameworks and their sustainability implications

The new challenge of high performance building design demands greater resilience achieved at a minimum environmental cost. However, the integration of sustainability and resilience and the circumstances in which the two are synergistic or antagonistic remains a persistent knowledge gap. The objective of this study was to narrow this gap by reviewing existing resilience frameworks. Seven were identified and four formed the basis of a sustainability evaluation. Eighty-eight strategies were tabulated, reviewed, and categorized into five resilience themes risk avoidance, passive survivability, durability and longevity, redundant systems, and response and recovery. They were then qualitatively identified as positive, negative, or conditional in terms of sustainability. Four case study design strategies hydronic radiant flooring, reduced window to wall ratio (WWR), additional thermal mass, and an intermediate mechanical floor were selected to explore life cycle tradeoffs supported from the literature. Of the 88 strategies, 35 were identified as positive, 14 as negative, and 39 as conditional. Those focused on risk avoidance, passive survivability, and response and recovery were largely conducive to sustain ability goals or dependent upon implemenlation or definition. Conversely, strategies that focused on durability and longevity as well as redundant systems tended to have divergent resilience and sustain ability performance. In the case of hydronic radiant flooring, the system's capacity to reduce the volume of the structure resulted in life cycle savings. Reducing the WWR increases impacts in the product and construction stage with case-specific effects in operational energy. Adding thermal mass results in a tradeoff between the upstream impacts with reduced on-site operational energy use. The intermediate mechanical floor evaluation results in a similar tradeoff, with increases in the product and construction stage and potential for improved energy performance. This qualitative evaluation supports broad conclusions about the sustainability implications of existing resilience frameworks and narrows the knowledge gap regarding the divergent effects of sustainability and resilience. It also lays the groundwork to incorporate quantitative modelling and hazard resistance within life cycle assessment of strategies to produce resilient and sustainable building designs. (C) 2017 Elsevier B.V. All rights reserved.