Which action best reduces embodied carbon in a building project?

• A. Increasing decorative finishes
• B. Selecting low-embodied-carbon materials and efficient construction practices
• C. Using more steel not efficient
• D. Increasing window area with single-pane glass

Answer: (B)

Reducing embodied carbon means cutting the greenhouse gas emissions tied to the materials and construction processes of a building, not just how it performs when occupied. The best action is to choose materials with low embodied carbon and to use construction practices that minimize waste, energy use, and transportation emissions. This includes selecting recycled-content or low-carbon alternatives (like cement with lower clinker content, or timber and recycled steel), and designing to use less material overall. It also involves construction methods such as prefabrication and efficient sequencing that reduce on-site energy use and waste, and designing for disassembly so materials can be reused.

Adding decorative finishes increases the amount of material and associated manufacturing emissions. Using more steel tends to raise embodied carbon unless it’s replacing higher-carbon materials, and increasing window area with single-pane glass adds more material and production energy while offering less thermal performance, which correlates to higher overall impacts.