Precast Concrete Life-Cycle Assessment and High-Performance Design
Learning Objectives:
- Define the term high performance as it relates to sustainable solutions in the built environment.
- Discuss the contribution a life-cycle assessment (LCA) can make in understanding a material’s environmental impact and continued improvement in its manufacturing and use phases.
- Identify where the precast concrete industry is making improvements in the manufacturing process to reduce adverse environmental impacts.
- Cite the key findings of a third-party LCA on precast concrete that are relevant to sustainable design decisions.
Credits:
Building owners, designers, and users are demanding that structures look great, perform better, provide multi-hazard protection, and do so sustainably. Enter the world of high performance. High-performance design and structures challenge us to optimize all relevant attributes, on a life-cycle basis for a project, and do so while minimizing negative environmental impacts.
To accomplish this, we must better understand the environmental impact of the materials and systems we use. Many manufacturers tout the sustainability of their products, yet very often their claims are unproven by scientific data. Government agencies, professional organizations, and corporations alike are seeking fact-supported methods of gauging the environmental impact of their products. So as sustainable design has evolved, so has the ability to better quantify and understand environmental impacts.
One approach that is gaining wide acceptance in the architectural and building community is life-cycle assessment (LCA). This tool gives business and industry the ability to look holistically at the environmental consequences of their products and to strategically address the environmental soundness of their operations—all with important implications for architects interested in specifying high-quality, sustainable building materials.
This article will discuss the definition of high performance as it relates to the building industry and how it contains attributes of sustainability. It will also discuss the components of an International Organization for Standardization (ISO)-compliant LCA, considered by many to be the gold standard of measuring sustainability and pinpointing areas for improvement. Also presented are the highlights and findings of this third-party LCA on precast concrete, as well as what those conclusions mean for the precast concrete industry as a whole, and for design professionals.
High-Performance Structures Defined
“High performance” is not an arbitrary term given to a structure that may have positive environmental features, it is a term that implies specific parameters that have been explicitly defined by law. The Energy Independence and Security Act of 2007 - 401 PL 110-140 proclaimed that a high-performance structure is one that “…integrates and optimizes on a life-cycle basis all major high-performance attributes including energy and water conservation, environment, safety, security, durability, accessibility, cost benefit, productivity, sustainability, functionality, and operational considerations.”
The 2007 law signaled a fundamental change in how green design is viewed. Sustainability, while a central aspect of high-performance buildings, was more specifically defined. No longer was sustainability merely a function of environmentally conscious design and construction, but performance on a life-cycle basis was a key and necessary component. While including the concepts and practices of sustainability, a high-performance building must demonstrate optimization of all relevant attributes of a project. Energy and water conservation, safety, security, and durability became requirements that must be integrated into a structure's overall design, construction, and performance.
For example, a parking structure will not have a huge energy component relative to a conditioned space building such as an office. However, both have energy requirements. The goal in high-performance design is to not forget, ignore, or otherwise overlook any of the relevant attributes in the optimization of the project. An important component to accomplishing this is to look at the interaction between systems and materials. For example, when you replace brick veneer with insulated precast concrete, how does this change affect the HVAC system, the construction schedule, or the indoor environmental quality, etc.?
