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Materials Red List

Your architect will tell you what looks good. Your contractor will tell you what meets code. Nobody tells you what the materials are doing to the people living inside. This guide does.

How this list was built

Every entry is cross-referenced against the Living Building Challenge Red List (2025 update, 2,073+ chemicals), IARC carcinogen classifications, EPA health advisories, and peer-reviewed research from institutions including Harvard T.H. Chan School of Public Health, the University of Michigan, and the National Academies of Sciences. Risk levels reflect both the severity of health effects and the likelihood of residential exposure. This is not a complete list of every harmful substance in construction. It is a focused guide to the materials most commonly encountered in residential projects, and the ones most likely to affect the people living inside.

Beyond the list

Knowing what to avoid is the easy part. Knowing what to specify is the hard part.

Every material decision involves trade-offs between performance, aesthetics, cost, and health. If you want help navigating those trade-offs for your specific project, we are currently taking on new work.

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