Using Life Cycle Assessments to select healthier building materials

Balancing environmental, wellbeing and ethical considerations in selecting a building material is a complex process - here’s how a Life Cycle Assessment can help.

Image credit: Parson New School - Healthy Materials Lab

Impacts of the Built Environment

Buildings contribute to around 40% of the world’s energy use, a large accelerator of global warming. Climate change causes countless problems for both humans and the environment including increased disease spread, extreme weather events, water scarcity, deteriorated air pollution, and much more.

Building material choices and developments are key factors in reducing the built environment’s atmospheric emissions. Those who inhabit the buildings are affected by construction and design choices, as well as those who live near or work in material extraction and manufacturing facilities, as they are closer to contaminated regions.

Often, those who are the most impacted by climate change and construction-related emissions have the fewest resources. Therefore, the negative impacts caused by building construction and material choices become not only an environmental issue, but also a human health and equity issue.

What is a Life Cycle Assessment?

Life Cycle Assessments are useful exercises to determine the environmental impacts of a building, material, or product over its entire life cycle. The goal is to reduce the carbon footprint and costs of a material throughout its life to help make smart building decisions for a more sustainable future.

Often, the use phase is the only consideration when making building decisions. However, all phases including raw material extraction, manufacturing, construction, use, end of life (disposal, recycling, etc.), and transportation between each phase need to be included for a true picture.

Life Cycle Assessments contain two prongs: Life Cycle Analysis (LCA), which considers the environmental impacts throughout the life of a material, and Life Cycle Costing (LCC), which considers purchasing and operating costs and savings over the life of a material.

Applications of Life Cycle Assessment

When considering the potential applications of conducting a Life Cycle Assessment, you must first determine what you want to measure and what to include in your system boundary.

There are different boundaries or limits that can be placed on any life cycle assessment, which may be determined based on the information, time, or resources available for a material or interested party.

Cradle to Cradle: end of life disposal is circular / involves recycling to avoid producing more waste

Cradle to Grave: manufacturer of the material is responsible for managing the waste they produce

Cradle to Gate: from resource extraction to factory gate (before delivery to customer)

Once the stages to include have been determined, the next step is to create a process flow diagram of the material in question, illustrating what happens over the material’s life cycle and which processes lie within the system boundary.

It is important to pay attention to what is included in the system boundary when comparing products or materials to understand the assessments.

After clarifying the steps required to produce the material in question, these phases can then be quantified into emission outputs and costs of interest from the data collected. These quantifications can then be used by a design team to make educated decisions between different materials or products.

The Goal - towards closed loop circular building materials

Nature is filled with ‘closed-loop cycles’, meaning resources are consumed, reused, and in a sense ‘recycled’ over and over again in a harmonious process that does not produce waste. There is no “disposal” stage in a natural life cycle in other words.

Man-made products on the other hand break this loop, often creating open or linear systems in which new resources are constantly added in, and then removed from the system as waste at the end of life. This process is fundamentally damaging to the environment especially when scaled up to accommodate for the global population today.

The goal therefore is to eliminate waste via strategies such as recycled content, down-cycling, or the use of organic and natural materials.

How Can This Concept be Applied to Materials?

Ideally all building materials would be ‘closed systems’, where at the end of life, they are reused, salvaged, and repurposed to serve another need. This reduces waste and the need for further extraction from the earth’s limits resources.

When considering which materials to utilize, look for materials with Product Declarations, which contain information about the impacts of a material and can better inform decisions. The LEED standard, for example, has several credits related to the use of product declarations, encouraging the implementation and use of available information.

Health Product Declarations (HPDs) and Environmental Product Declarations (EPDs) both contain important disclosure information, with HPDs focusing on ingredient impacts on human and ecological health, while EPDs focus on providing information on a products environmental impact.

See more on this subject in the ESG / Sustainability section of this site.

Resources

BREEAM LCA