When a building owner with a net zero commitment is deciding whether to renovate or rebuild, the conversation often starts with what each option will cost and how much energy the finished building will use. While both options are still on the table, there’s another question worth asking and that is “How much carbon will each option release before anyone moves in?” Manufacturing steel and concrete, transporting materials and putting them in place all generate emissions.
Those upfront embodied emissions are beginning to shape what public agencies buy and what design teams must demonstrate under building codes. Tackling embodied emission is critical to the net zero pathway because while operating emissions can fall as a building gets more efficient, upfront embodied emissions are locked in once they’re released.
Public procurement can require suppliers to disclose emissions and meet limits for specific materials. An Environmental Product Declaration (EPD) reports a product’s environmental impacts, including its global warming potential, and can help teams compare products that serve the same function. A whole-building Life-Cycle Assessment (LCA) can show how a different structural system, less material or reuse of an existing structure changes a project’s emissions.
Embodied carbon is also beginning to find its way into building regulation. From low-carbon material requirements and whole-building LCAs to EPD disclosures and public procurement policies, states are starting to translate measurement into action. Three examples illustrate how this shift is taking place.
California: From Procurement to Building Code
California began using its purchasing power through the Buy Clean California Act, which took effect in 2018. Beginning July 1, 2022, covered public works contracts had to apply emissions limits to eligible materials such as structural steel, reinforcing steel, flat glass and mineral wool board insulation. Contractors use EPDs to document compliance.
The California Green Building Standards Code, known as CALGreen, extended embodied carbon requirements to covered nonresidential projects, including private development, on July 1, 2024. On January 1, 2026, the threshold for projects under the California Building Standards Commission’s authority dropped from 100,000 to 50,000 square feet. One compliance path uses a whole-building LCA to show at least a 10% reduction in global warming potential against a reference building, excluding operating energy. Another uses EPDs to show that specified materials, including concrete, meet emissions limits. For qualifying additions and alterations, teams can also comply by retaining at least 45% of the existing primary structure and enclosure, as defined in the code. A code supplement scheduled for July 1, 2027, consolidates the existing compliance paths under one section on embodied carbon reduction.
Washington: Bringing Embodied Carbon into Local Codes
The Washington State Building Code Council recently voted to include Appendix S on embodied carbon reporting and reduction in the state’s adoption of the 2024 International Building Code. Cities and counties can choose to adopt the appendix beginning in 2027. As in California, teams can comply through materials selection, whole-building life-cycle modeling or reuse of an existing building. Washington’s materials path allows teams to average emissions across covered materials.
The appendix gives local officials and project teams a way to gain experience with embodied carbon in design, permitting and procurement. It also gives manufacturers a clearer sense of what project teams will ask them to document.
Massachusetts: Building a Roadmap for Statewide Action
The Commonwealth of Massachusetts created the Embodied Carbon Intergovernmental Coordinating Council through its 2024 climate law. In January 2026, the council submitted its first Embodied Carbon Reduction Plan to the legislature. In it, the plan’s executive summary calls embodied carbon “the sleeping giant when it comes to sources of climate pollution.”
For contracts advertised after mid-2027, the plan recommends collecting EPDs and material quantities for covered state projects. It also recommends whole-building LCAs for qualifying state-managed new construction and major renovations involving at least 20,000 square feet in a single building when prime contracts are advertised after that date. For qualifying contracts advertised after mid-2028, the plan proposes project-average emissions limits for ready-mix concrete, asphalt mixtures, reinforcing steel and structural steel.
The Massachusetts Department of Transportation already requires EPDs for concrete when its contract documents call for them.
For the statewide base building code, the Council recommends starting with credits for lower-carbon concrete and insulation. In the longer term, it proposes allowing teams to meet future requirements through building reuse, a whole-building LCA, or EPDs showing that specified materials meet emissions limits. Those provisions would require separate adoption by the Board of Building Regulations and Standards. The plan cites 2028 as the board’s target for finalizing the next code edition and leaves the timing of longer-term embodied carbon requirements open.
From Regulation to Verified Performance
The buildings we put up and the ones we keep will shape emissions for decades. The developments in California, Washington and Massachusetts point to a broader shift in how the building industry will need to approach decarbonization. As embodied carbon moves into building codes, procurement requirements and material standards, owners and design teams will increasingly need more than emissions disclosures or reduction commitments. They will need a way to measure performance across the building, understand where emissions are coming from, establish credible reduction plans and demonstrate that those reductions are being achieved.
This is where independent verification becomes increasingly important. Global Network for Zero (GNFZ) supports this transition through an independent, performance-based net-zero certification framework for buildings and portfolios. Grounded in the GHG Protocol, GNFZ takes a comprehensive approach to emissions accounting, addressing operational emissions alongside embodied carbon and other sources of environmental impact. Its process helps organizations establish a baseline, identify reduction opportunities, implement a plan and verify progress over time. This includes evaluating whether material choices deliver the projected emissions reductions and accounting for the embodied carbon of future renovations alongside operational emissions. Annual recertification helps ensure that progress continues as buildings change. Rather than prescribing a particular rating system, technology or pathway, GNFZ provides a consistent framework for measuring results and demonstrating progress across different building types, markets and regulatory environments.
As states continue to develop policies that bring embodied carbon into the mainstream, the opportunity is to move beyond compliance toward sustained, measurable reductions. Whether responding to emerging requirements, preparing for future regulation or advancing voluntary net zero commitments, building owners and design teams need credible ways to demonstrate that their decisions are making a difference.
Learn how Global Network for Zero can help your organization measure, reduce and verify building emissions, including embodied carbon, at globalnetworkforzero.com.