In architecture, engineering, and construction (AEC) projects, there are two types of carbon emissions to be aware of—operational carbon and embodied carbon. Operational carbon represents any emissions released from a building’s ongoing operations and day-to-day activities, such as lighting and space conditioning. Embodied carbon encompasses any emissions associated with building materials and products from resource extraction, transportation, production, installation, maintenance, demolition, and end-of-life disposal.

Decarbonization in the AEC industry has historically focused on reducing operational carbon emissions. Strategies such as transitioning to LED lighting, incorporating energy-efficient HVAC systems, and installing on-site renewable energy systems have helped to significantly reduce the impact of operational carbon in recent years. Now, embodied carbon is getting a closer look.

With state and local carbon reduction and emissions regulations continually taking effect across the country, large-scale decarbonization is quickly becoming a priority in AEC projects.

• New York, New York: Local Law 97 (LL97) plans to decrease emissions from large buildings by 40% by 2030 and to net zero by 2050.
• Boston, Massachusetts: Boston’s Building Emissions Reduction and Disclosure Ordinance (BERDO) sets gradually decreasing emissions limits on large buildings, with the goal of net zero by 2050.
• Denver, Colorado: The Net-Zero Energy (NZE) New Buildings & Homes Implementation Plan calls for all new buildings and homes to be net zero by 2030 and all existing buildings and homes to be net zero by 2040.

To best meet and maintain these standards in our projects, the AEC industry should take a holistic approach—one where both operational and embodied carbon are carefully and equally considered.

Engineering for Efficiency

When starting a project, it is essential to begin with a comprehensive outlook of the work ahead. For decarbonization projects, this means looking beyond equipment selection to see the scope more holistically. Equipment is only one component for reducing carbon emissions, and the most efficient equipment can fail to operate efficiently when factors such as design, configuration, and efficient sequences of operation are overlooked.

In addition to efficient equipment selection, teams must work toward appropriately sizing, staging, and controlling equipment. This means carefully designing fluid velocities, pressure drops, and layouts, as well as choosing the correct setpoints and water temperatures according to a building’s size and intended use. When specifically targeting embodied carbon, this could include prioritizing hydrogen-based steelmaking—which can reduce emissions from steel manufacturing by up to 95%. By implementing a variety of energy optimization strategies, our team can efficiently decarbonize from a project’s onset.