The Natural Stone Council's Development of ANSI/NSC-373


The Natural Stone Council’s Development Of ANSI/NSC-373

The Natural Stone Council is a collaboration of business and trade associations that have joined forces to promote the interior and exterior use of natural stone in residential, commercial, government, institutional, and educational applications. Its new standard, known as the ANSI/NSC 373 Natural Dimension Stone Standard, puts criteria into place for the industry to measure the sustainability of natural stone production.

While the sustainability of natural stone remains unquestioned with regard to longevity and durability of structures, this new standard expands the meaning. How the stone is quarried, processed, and transported is now incorporated into the definition, which still places some importance on the longevity of the stone.  The way that natural stone is used has an effect on the structures, environments, and people within them.

Developed by the Natural Stone Council in conjunction with NSF International through the National Center for Sustainability Standards, this standard sets forth a series of well-defined environmental, ecological, social responsibility and human health requirements for stone quarries and processors.

Now, arguably more than ever before, sustainability is at the top of people’s minds within the construction industry. This standard aims to reassure everyone from designers to owners to material manufacturers, all the way to the end user of the project. For architects and owners, this standard confirms that their building’s stone is produced in a way that is both environmentally and socially responsible.

In 2014, the Natural Stone Council established the sustainable stone certification with several objectives. One is to recognize and drive sustainability practices in the natural stone industry with an emphasis on continuous improvement. Another is the development of a multi-stakeholder, science-based approach that is both third party verified and recognized by the green building movement as an indicator of leadership in sustainable performance. The Standard also provides an important opportunity to educate key members of the design and building professions, end users, government and environmental advocacy groups about the production of natural stone products This voluntary Standard emphasizes the disclosure of information necessary to mitigate negative impacts and promote efficiencies in the production of natural dimension stone products in a sustainable manner..  

What It Is And Who It Impacts

Both quarriers and processors can certify to the ANSI/NSC 373 Standard, which includes certifying to the companion Chain of Custody Standard. This companion standard drives sustainability through the supply chain, and ensures that they are also handled in a manner that ensures the sustainability.  Throughout each step in the stone’s process, the standard must be conformed to or certification will be lost. Though they would not certify to the ANSI/NSC 373 standard, Distributors and Brokers can certify to the Chain of Custody standard to ensure they are certified to maintain the certification throughout the supply chain. 

The standard covers nine elements of a quarrier and fabricator’s respective operations. They are: water usage and recycling, custody and transportation, site and plant management, land reclamation and adaptive use, corporate governance, energy usage and conservation, management of excess process materials and waste, safer chemical and material management, and human and health considerations. Additionally, there is an optional facet that is referred to as “innovation.”

Each company is certified on a site-specific basis. That means that even though a company may have several quarries, only one may be certified at a time. However, they are able to pursue certification for all of their locations.

In total, there are 18 requirements within the standard and a possibility for a site to receive 41 points. Depending on a company’s scores, they are assigned a bronze, silver, gold or platinum certification. Companies achieving bronze, silver, and gold certifications have room for improvement in the respective areas they may not have gotten the maximum points.

When stone companies are looking to receive the ANSI/NSC 373 certification, a third party such as NSF International will verify via a desk audit as well as a site audit. First, organizations will go through a document review. This is followed up with an on-site audit.

This series of elements allows companies to set a benchmark for themselves with the intent of continuous improvement.  With that in mind, recertification takes place every three years. The second and third year of certification add a surveillance review with a documentation review only, and the fourth year involves an on-site audit in addition to the documentation review for recertification. At any point, companies can upgrade to a higher level of certification.

For contractors, this is particularly relevant, as the standard has been accepted to LEEDv4 and the Living Building Challenge. Thus, it will continue to come up in conversations where stone is a specified building product on a project that has sustainability at the forefront. By understanding the intent of the standard along with what goes into becoming certified, contractors will be able to become a resource in the recommendation of particular materials that will align with a project’s goals.

The Standard’s External Recognition

Groups like the International Living Future Institute (ILFI) and US Green Building Council (USGBC) make it a priority to educate and inform thousands of architects, builders and developers of the best choices when it comes to design and materials. Their respective building rating systems, ILFI’s Living Building Challenge (LBC) and USGBC’s Leadership in Energy and Environmental Design (LEED), specifically set forth guidelines for the sourcing of responsible materials.

For the Natural Stone Council to align and getrecognition from those two groups was crucial. In order to do so, connections were made with the appropriate contacts at ILFI, USGBC, Green Globes and the International Green Construction Code to present the story of the new standard. This was essential for the groups to understand the long-term sustainability practices that have been in place for natural stone and the continuous-improvement mindset that the standard supports.

To develop ANSI/NSC 373 for alignment with LEED and LBC, the NSC Sustainability Committee worked closely with third-party organizations including Jack Geibig at Ecoform of Knoxville, Tenn., and NSF International of Ann Arbor, Mich., to determine the sustainable footprint of how stone is quarried, transported and processed. In addition, ANSI/NSC 373 was developed using the consensus-based ANSI (American National Standards Institute) process and can be applied internationally with certification by a third-party certifier like NSF International. 

Certified Organizations


Cold Spring, MN

Platinum Certified: Charcoal Quarry, St. Cloud, MN; Mesabi Quarry, Babbitt, MN; Rockville Quarry, Rockville, MN

Gold Certified: Coldspring Headquarter Campus Facilities (Processor), Cold Spring, MN

Michels Stone / Anderson Bros & Johnson

Fond du Lac, WI

Gold Certified: Beaver Dam, WI (Quarry); Fond du Lac, WI (Procesor); Fond du Lac, WI (Quarry)

Northern Stone Supply Inc.

Oakley, ID

Platinum Certified: Oakley, ID (Processor), Oakley, ID (Quarry)

Stony Creek Quarry Corporation

Branford, CT

Gold Certified: Branford, CT (Quarry)

TexaStone Quarries, LLC

Garden City, Texas

Gold Certified: Garden City, TX (Quarry)

Silver Certified: Garden City, TX (Processor)

The Natural Stone Council And ANSI/NCS-373 Production of Natural Dimension Stone Standard Words: Masonry Magazine Photos: Coldspring, DC Real Estate Photo, Natural Stone Council, Masonry Magazine

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