Whole Building Life Cycle Analysis (LCA)

Until recently, sustainable design mainly focused on building operation and interaction with its environment – energy and water use, community development, and health, safety and welfare.  Decision makers know that construction material choice can significantly affect a project’s carbon footprint, but the only practical design option has been to specify longer life, more durable materials.  A more complete building carbon footprint assessment was  difficult, time consuming or even impossible because the necessary information and guidance were unavailable.  Governments and advocates for more sustainable decision making have worked to remove those barriers to encourage more comprehensive carbon footprint assessment. Whole-building lifecycle assessment (LCA) standards, lifecycle inventory (LCI) databases, and software now make it possible to look at all phases of a building, from material extraction and production through construction to decommissioning and, where possible, recycling into a ‘new’ useful material.

LCI data assesses the environmental impact of the production of each material. In LCA, the LCI data for each material is multiplied by the expected number of replacements over the service life of the project. There are LCI databases in Europe, Australia, the United States and elsewhere.  There are finally enough materials in them, including all of the commonly used metals, for Whole Building LCA to be possible.

The third party certified LCI data used must be either from the individual supplier whose product is used or average data from the industry association in the specific country/region in which the material was produced because of energy source and environmental regulation differences. This is critical for a valid LCA analysis. Where databases have not yet been developed, Environmental Product Declarations (EPDs) from the producer or industry association can often provide the necessary information. Stainless steel is in these databases and many producers have EPDs.

Proving its Long-term Mettle: Longevity, whole-building LCAs, and stainless steel,The Construction Specifier, provides more information on available resources, examples of stainless steel use in sustainable design and documentation of the material’s durability.

As resources become more developed, Whole Building LCA will become a regular part of sustainable design but, at this point, it is still optional in The International Green Construction Code (IgCC) and the most recent versions of the three widely used voluntary rating systems – US Green Building Council (USGBC) Leadership in Energy and Environmental Design (LEED), Green Star, and Building Research Establishment Environmental Assessment Method (BREEAM).

Determining Material Replacement Frequency
Material service life prediction is necessary for LCA. This may seem challenging but site assessment tools and comparative long-term corrosion testing data for metals are available. Here are a few resources to assist with that process:

Design & Selection Criteria

• IMOA Site Evaluation & Selection System
• Selection System Case Studies
• Designing Green or Vegetated Walls

Comparative Metal Corrosion Data

• Guidelines for Corrosion Prevention
• Evaluating Coastal Salt Exposure
• Evaluating Deicing Salt Exposure

Capabilities & Limitations of Architectural Metals

• Part 1
• Part 2