Building Better: The Key Stages of a Building Life Cycle Assessment

A building life cycle assessment (LCA) is a major determining factor in how sustainable a structure is. It is the best framework industry experts have to analyze the climate impacts of built environments — one of the most damaging categories when considering the amount of carbon emissions. These are the crucial stages of an LCA, which are easily executable, scalable and effective in decarbonizing infrastructure.

1. Product Stage

A building life cycle assessment begins with the product stage. The American Institute of Architects Guide to Building Life Cycle Assessment in Practice document initially outlined the phases. Its foundation comes from the internationally acclaimed ISO 21931 standard. Over the years, it has been a collaborative effort between agencies to refine the process. 

Each stage contains the most important aspects of that section making the most impact. For the Product Stage, this includes the phases relevant to raw materials, extraction and movement, such as:

• Extraction and production
• Transport 
• Manufacturing

The best way to do well in this category is to source materials ethically and locally. Many heavy metals and mining efforts damage the environment and increase the amount of embodied carbon for a building. Instead, prioritizing recycled, salvaged, reclaimed or repurposed materials with environmental certifications can make everything more eco-friendly from the beginning.

Then, transportation emissions should be as low as possible by using low-emission alternatives or investing in electrified fleets.

Companies can incorporate these shifts in stages to ensure scalability and long-term sustainability. This is more important than implementing costly procedures for a single project and giving up on subsequent efforts.

2. Construction Stage 

The construction stage covers three main aspects of building the structure:

• Transport
• Construction
• Installation

Builders can improve their building life cycle assessment in a few ways. The first is by establishing a waste management plan. Most of the negative impact of this stage comes from excessive construction and demolition waste. Set recycling targets and adequate infrastructure on the building site to curb this. 

Additionally, buildings can use energy-efficient construction materials to lower idle time and save on fuel resources. This is one of many smaller contributions that can have a major impact.

Companies that want to take it a step further can engage in modular infill or prefabricated builds. It cuts the time and waste generated during construction, as most of it is performed during manufacturing. 

3. Use Stage

The use stage is the most involved and complex because it covers most of the building’s life cycle. How do residents and visitors use the space? This encompasses:

• Use
• Maintenance
• Repair
• Replacements
• Refurbishments
• Energy use
• Water consumption

This is where homeowners, renters, and other personnel can expand upon the good foundations that construction workers have laid out. The way people interact with the structure over its life influences the LCA, which people can predict based on its intended purpose and features. For example, if it has high-efficiency tools, the Use Stage’s impact will be less than an older building.

Builders should make structures compatible with smart technologies, as they give residents unparalleled insights into how to reduce resource consumption. A smart thermostat or advanced HVAC system could inspire people to keep cutting their numbers as low as possible. It could help the building support renewable energy in the future, making the LCA even brighter.

However, the use stage is helped even more by caring for the building. All stakeholders should engage in preventive maintenance and upkeep to make the infrastructure’s materials, technologies and elements last as long as possible without excess waste and renovation.

4. End-of-Life (EOL) Stage 

The EOL phase has the potential to generate the most trash, but companies can mitigate it with a plan, much like they did during the construction phase. This includes:

• Demolition
• Transportation
• Processing
• Disposal

Tearing down a building, transporting its heavy materials, including heavy metals and concrete, is highly consumptive. If companies must engage in a demolition, they should have a salvage plan. If nuclear plant decommissioning projects can salvage building materials from previously radioactive sites, other residential and commercial builds, rurally or in urban spots, can do the same. 

However, retrofits and renovations are ideal compared to demolition. It repurposes existing materials, which reduces reliance on harvesting new natural resources. These projects can still establish composting, recycling and upcycle sorting protocols on sites to make the most of what is already there.

5. Beyond the Boundary 

After a building’s end of life, its life cycle assessment is not over. Ideally, everything should support a circular economy. Instead of the cradle-to-grave mentality construction has adopted, it should focus on a cradle-to-cradle operational structure. This brings back as many materials from EOL infrastructure into the industry as possible. This is why the “Beyond” phase includes:

• Reuse
• Recycling
• Recovery 

There are too many people without places to live because of the housing crisis. Even commercial buildings are in short supply. Construction workers cannot build fast enough to meet demand, and this isn’t even considering natural disasters like floods and earthquakes ravaging countless other buildings worldwide.

Therefore, climate resilience and adaptability must be a priority for buildings to exist beyond the EOL stage. Builders do this by keeping thorough documentation of the components with plans on how to reuse them. Retrofits should make infrastructure even more resource-aware and well-defended against the elements than it was in its previous life.

Companies help their peers by collaborating and sharing their LCAs with competitors. A building life cycle assessment aims to lower emissions and waste to make infrastructure more compatible with an eco-friendly future. This is not achievable by keeping secrets from other construction companies. 

A Perfect Building Life Cycle Assessment

These key stages guide LCAs into the useful processes and documents they are today. Eventually, they will become more than a staple of sustainable structures — they will be required to analyze a building’s longevity and climate impacts. While they could include even more information to enhance their comprehensiveness, they are a wonderful foundation for building a better world.