Life-Cycle Assessment-Based Environmental Performance Targets for Buildings: What Is Next?

Introduction

Commonly used building environmental performance assessments are based on the notion of less is better, rather than on well-defined performance targets grounded in first-order principles. Performance benchmarking systems currently used in building assessments have little, if any, connection with planetary boundaries or equivalent constraints. This chapter argues for the need to develop science-based absolute performance benchmark values derived from environmental limits such as planetary boundaries. It starts with a background review of works undertaken on life cycle assessment-related environmental performance targets of buildings; argues for more meaningful impact targets; highlights the potential of including performance targets in communication tools; sets the context for early design intervention; highlights the utility of industry standards, guidance, and software tools; and ends with highlighting areas for future research that informs better building design practice.

Climate change, resource depletion, biodiversity, and toxicity are among the many global challenges humanity is increasingly facing. Cities with their buildings play a critical role as entry points for developing and implementing solutions that aim at addressing these challenges (Seto et al., 2014; Kennedy et al., 2015; Solecki et al., 2018; Swilling et al., 2018). Buildings globally are responsible for 40% of global energy and resource use, 33% of greenhouse gas emissions, and 25% water use (UNEP, 2013). For the world to meet the ambition of limiting global temperature increase by 2100 to 1.5^oC based on the Paris Agreement, and thereby avoiding unprecedented climate change driven catastrophes, greenhouse gas emissions from the building sector need to be reduced by 80–90% by 2050 according to Kuramochi et al. (2018) as cited in IPCC (2018). The current global building stock at 223 billion m² is expected to increase by 230 billion m² in the next four decades (Bionova, 2018). The magnitude of the new additions is equated to adding to the building stock an entire city of New York every month for the next forty years. The 1.5^oC goal requires addressing both new construction and retrofitting existing building stock.

Life cycle assessment (LCA) is commonly used in assessing the environmental impacts of buildings at different levels with varying emphasis on different aspects. Diverse studies focusing at building-level environmental performance have explored the circular economy for buildings (Hossain and Ng, 2018) and building elements (Eberhardt et al., 2019a); construction waste optimization (Jalaei et al., 2019); integrated design (Leoto and Lizarraldea, 2019); parametric design and building optimization (Szalay and Kiss, 2019); building rehabilitation, refurbishment, and repurposing (Thibodeau et al., 2019; Vilches et al., 2017; Assefa and Ambler, 2017); embodied environmental cost (Roh et al., 2019); design for disassembly (Eberhardt et al., 2019b); datasets and tools (Emami et al., 2019); streamlined data collection (Tecchio et al., 2019b); uncertainty and surrogate data (Tecchio et al., 2019a); and result visualization (Kiss and Szalay, 2019). Other studies have looked for solutions and insights at scales larger than buildings (Fouguet et al., 2017; Nault et al., 2018; Assefa, 2019).