A code change proposal establishing a formal pathway for using salvaged lumber in structural applications has been approved for adoption into the 2027 International Building Code (IBC). The new provision allows salvaged lumber to be used at up to 90% of standard design values when verified by approved entities such as grading agencies or registered design professionals and found to meet requirements related to grading, decay, fire and insect damage, structural integrity, and heat exposure. The update provides long-awaited code guidance for the safe reuse of structural lumber while supporting material reuse and embodied carbon reduction goals. A public comment hearing for the proposal was held in April during ICC Leadership Week, and the hearing can be viewed here: https://www.cdpaccess.com/videos/12240/.
Meanwhile, a second embodied carbon-related code change proposal is under consideration in Washington State and is open for public comment through June 12, 2026. The proposed amendment would introduce an optional Embodied Carbon Appendix (Appendix S) to the Washington State Building Code. If adopted by local jurisdictions, the appendix would require reporting on embodied carbon emissions for covered projects in support of the state’s goal to reduce greenhouse gas emissions by 95% by 2050. Two versions of Appendix S are currently under review: Option 1 includes multiple compliance pathways—including product-level compliance, whole building life cycle assessment (WBLCA), and building reuse—while Option 2 focuses exclusively on a WBLCA approach. Additional information, including the CR-102 document and instructions for submitting comments to sbcc@des.wa.gov, can be found here: https://sbcc.wa.gov/2024-international-building-code-embodied-carbon.
The National Ready Mixed Concrete Association (NRMCA) has also updated its Guide to Improving Specifications for Ready Mixed Concrete to include commentary on embodied carbon reduction, responsible sourcing, and alignment with LEED v5 and Envision v3 credit systems. The guide includes recommended specification language and optional clauses supporting lower global warming potential (GWP) concrete mixes, responsible sourcing practices, and sustainability-focused project goals.
In related research, the University of Cambridge is seeking participation in a new study examining how structural optimisation is being applied in practice to improve structural efficiency and reduce embodied carbon in construction. The survey is intended for structural and civil engineers, contractors, sustainability specialists, and researchers involved in building design, infrastructure, and construction. Conducted under Dr. Rob Foster in the Department of Engineering at the University of Cambridge, the research aims to better understand current tools, methods, and practical challenges surrounding structural optimisation in the industry. The survey takes approximately 15–25 minutes to complete and has received ethical approval from the University of Cambridge.
Take the survey here:
https://cambridge.eu.qualtrics.com/jfe/form/SV_3IggsmWy1VjB6dM
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