International Green Construction Code (IgCC): Model Code for Sustainable Buildings

Introduction

The International Green Construction Code (IgCC) is a model green building code developed by the International Code Council to provide enforceable sustainability requirements that can be adopted by law. It builds on and extends traditional building codes by adding provisions for energy and water efficiency, resource conservation, indoor air quality, and life-cycle environmental performance of materials and systems. As a model code, it is voluntary until it is adopted by a jurisdiction, at which point it becomes legally binding for covered projects.

Reporting implications

In jurisdictions that adopt the IgCC, companies working on covered building projects must meet materials documentation and transparency requirements as part of permitting and compliance. Chapter 9 of the IgCC, “Materials and Resources,” establishes rules for Environmental Product Declaration (EPD) submissions:

• EPD coverage thresholds: EPDs must be submitted for building products that together represent at least 25 % of the total estimated cost of permanently installed products, or a minimum of 30 EPDs, with products from at least 10 different manufacturers and at least 20 different products included.

• EPD requirements: EPDs used to comply must be third-party verified Type III EPDs consistent with ISO 14025 or ISO 21930 and have at least a cradle-to-gate scope. Where product-specific EPDs are unavailable, other third-party reviewed LCA reports may be used as an alternative method for showing compliance.

• GWP reporting: For each product with an EPD, the global warming potential (GWP) reported must be multiplied by the quantity used and included in a report provided to the project owner and the authority having jurisdiction (AHJ).

These provisions mean manufacturers supplying products to buildings governed by an adopted IgCC must have EPDs (or equivalent LCAs) ready before installation and permit sign-off; architects, contractors, and owners must plan for EPD submittals as part of compliance documentation. An EPD is a transparency tool that quantifies environmental impacts across a product’s life cycle, typically based on ISO life-cycle assessment standards.

Status & Outlook

The 2024 edition of the International Green Construction Code is the latest model code iteration and integrates the most current sustainability requirements in coordination with other ICC model codes such as the International Energy Conservation Code (IECC) and ANSI/ASHRAE standards. It is designed to be adopted as law by states, counties, or cities that want mandatory green building requirements. IgCC adoption is not universal. Where adopted, it creates legally enforceable standards that project teams must meet to obtain building permits and certificates of occupancy. The code has been adopted or is in use in a number of U.S. states and localities, and agencies such as the U.S. General Services Administration and Department of Defense reference it for federal projects. As sustainability and embodied-carbon transparency become more central to procurement and regulation, EPD requirements in building codes like the IgCC are likely to grow in importance for material suppliers and project teams alike.

Resources

• International Green Construction Code (IgCC) – ICC official overview.

• IgCC Chapter 9 Materials and Resources – EPD and GWP provisions (2024 IgCC).