NSI 373 New Standard Takes Effect — A New Phase for Natural Stone Sustainability Certification
Summary: Beginning Q1 2026, the revised ANSI/NSI 373 Sustainable Production standard from the Natural Stone Institute took effect. The update extends third-party verified EPD requirements to all certification tiers and strengthens quarry chain-of-custody documentation. This article examines the core changes and their impact on the global stone trade.
1. What Is ANSI/NSI 373
ANSI/NSI 373 is a sustainable production standard for natural dimension stone developed by the Natural Stone Institute. First published in 2014, it provides a verifiable sustainability framework covering water management, energy efficiency, waste handling, land reclamation, worker health and safety, and corporate governance.
Unlike LEED or BREEAM, which certify buildings, NSI 373 targets the production stage itself and is regarded by the design community as the primary basis for evaluating the environmental credentials of natural stone.
2. Three Core Changes in the 2026 Revision
According to a March 2026 industry analysis by StoneTrades, the revision introduces three material changes:
Change 1: EPDs Mandatory Across All TiersPreviously, only Tier 3 (exemplary performance) required a full ISO 14025-compliant EPD. From 2026, Tier 1 and Tier 2 operations must also publish third-party verified EPDs, with a compliance window extending to mid-2027 for existing certificate holders.
Change 2: Tighter Quarry Chain-of-Custody RequirementsProcessors must now trace finished slabs back to a named quarry and specific block number, with audit evidence updated annually. This responds directly to project owners and ESG-focused procurement teams who demand documented material provenance.
Change 3: Social Responsibility Indicators Added to ScoringThe updated standard introduces social responsibility indicators aligned with the broader NSI Accreditation framework, including minimum worker safety thresholds and community impact disclosure. These are currently scored but not mandatory; NSI has indicated they will become required in the 2028 revision cycle.
3. Practical Impact on Stone Buyers
For architects, developers, and stone distributors, the 2026 changes mean:
LEED Credit Access: Stone sourced from NSI 373-certified operations will more directly support Materials and Resources credits under LEED v4.1 and the forthcoming LEED v5.
Supply Chain Due Diligence: Buyers should contractually require quarry provenance documentation rather than accepting generic "natural origin" declarations.
Cost Structure Shift: EPD preparation and third-party verification add cost, which may pass through to end prices, but over time helps filter for compliant, stable suppliers.
4. Implications for Chinese Stone Exporters
As a major global processing and re-export hub, China's stone industry—centered in Shuitou, Fujian and Yunfu, Guangdong—faces the challenge of obtaining and transmitting upstream quarry information. Because Chinese firms import blocks from Turkey, Italy, Brazil, and Iran for local processing, establishing a full chain from finished slab to overseas quarry block requires closer information-sharing with upstream partners.
Xiamen Hexin Stone Co., Ltd., established in 2014, specializes in the import and supply of Travertine, Limestone, Onyx, and Quartzite, maintaining close cooperation with overseas quarries. In the context of the NSI 373 revision, this direct-to-quarry sourcing model helps secure more transparent origin information upstream, providing downstream clients with clearer material traceability.
Frequently Asked Questions (FAQ)
Q1: Does NSI 373 certification apply only to U.S. companies?
A: No. ANSI/NSI 373 applies to all natural stone processors, regardless of location. For Chinese exporters targeting LEED-certified projects in North America, NSI 373 compliance is a significant advantage.
Q2: Will EPD mandates heavily impact small and mid-sized stone traders?
A: Impact depends on the export market. Firms serving high-end North American commercial projects should initiate EPD preparation promptly; wholesale distributors not directly involved in LEED projects face limited near-term impact but should monitor the trend.
Q3: Does Hexin Stone supply NSI 373-certified stone?
A: Hexin Stone works with overseas quarries to import and supply Travertine, Limestone, Onyx, and Quartzite. Regarding the sustainability certification status of specific quarries, clients are invited to confirm with our sales team during procurement discussions to align with project compliance requirements.
About
Hexin StoneEstablished in 2014 and headquartered in Xiamen, China, Xiamen Hexin Stone Co., Ltd. specializes in importing
Travertine, Limestone, Onyx, and
Quartzite. Our business covers blocks, slabs, hospitality and residential projects. We maintain close cooperation with overseas quarries and have a professional purchasing and sales team, providing meticulous services from block procurement to quality control. Basing on our philosophy of "All-win harmony, Reputation first," we sincerely welcome customers to visit, negotiate, and seek common development.
