Navigating the complexities of LEED v4 with concrete masonry

Concrete masonry units (CMUs) made with carbon dioxide (CO2) recycling technology were specified in the MGM National Harbor (Prince George’s County, Maryland) by architect of record SmithGroupJJR and design architect HKS Architects. The 195,000 CMUs resulted in a net carbon reduction of (3150 lb) of CO2. Images courtesy MGM Resorts International and HKS Architects

Environmental product declarations
The intention of Building Product Disclosure and Optimization−Environmental Product Declarations, is to encourage manufacturers to report and verify their products’ lifecycle impacts. The best tool to communicate impacts over a product’s lifetime is a tool known as an environmental product declaration (EPD). EPDs that quantify the impact from the raw material supply, transport, and manufacturing stages are called ‘cradle-to-gate,’ whereas those that go one step further to incorporate an end-of-life stage are called ‘cradle-to-grave.’

In order to achieve this particular credit, project teams have several options. One option is for project teams to use a minimum of 20 different permanently installed products from at least five manufactures that have issued public declarations disclosing the environmental impact of these products. In other words, a single manufacturer cannot contribute more than four EPDs to the total 20 that are required.

Each of the 20 must be unique—that is, the purchased finished product has a unique function, or is made by a different manufacturer. For example, two CMUs created by the same manufacturer with the only difference being their color would not be considered unique materials; thus, only one EPD would be able to count towards the required 20.

The most common method to comply with this credit is for manufacturers to issue product-specific International Organization for Standardization (ISO)-compliant, cradle-to-gate EPDs, or to use industry-wide generic EPDs. Industry-wide EPDs are valued at half value for credit calculation purposes, since product-specific EPDs are considered to be more reflective of an actual product’s environmental impact. (ISO standards include 14025, Environmental Labels and Declarations−Type III Environmental Declarations: Principles and Procedures, 14040, Environmental Management−Lifecycle Assessment: Principles and Framework, 14044, Environmental Management−Lifecycle Assessment: Requirements and Guidelines, and 21930, Sustainability in Building Construction−Environmental Declaration of Building Products.)

The second option of this credit involves “multi-attribute optimization.” The credit requires project teams comply with one of a list of criteria for 50 percent—by cost—of the permanently installed products on the project. One option is to demonstrate products have environmental impacts lower than industry averages in at least three of the following categories:

  • global warming potential (i.e. greenhouse gases [GHGs]);
  • depletion of the stratospheric ozone layer;
  • acidification of land and water sources;
  • eutrophication;
  • formation of tropospheric ozone; or
  • depletion of nonrenewable energy resources.

For this credit, some CMU manufacturers can issue EPDs for products made with recycled CO2 using proprietary technology that also reduces GHGs associated with manufacturing processes.

Sourcing of raw materials
There are two opportunities to achieve Building Product Disclosure and Optimization−Sourcing of Raw Materials. The first option is to publish a raw material source and extraction report, and the second is for the manufacturer to engage in sustainable leadership extraction practices. This is the credit that captures many of the credits from LEED 2009, such as recycled content and certified wood.

In Option 1, a raw material source and extraction report can be provided by either the raw material suppliers or the manufacturer themselves. The report must outline raw material supplier extraction locations and describe supplier’s commitments to:

  • long-term ecologically responsible land use;
  • reducing environmental harms from extraction and/or manufacturing processes; and
  • meeting applicable standards or programs voluntarily addressing responsible sourcing.

The project team must have a minimum of 20 permanently installed products from at least five manufacturers that have publicly issued these reports. Third-party-verified corporate social responsibility (CSR) reports that comply with a set of approved frameworks such as the Global Reporting Initiative (GRI) Sustainability Report are preferred (these reports contribute full value to the credit calculations), but self-declared reports are also acceptable (these reports provide half value).

The most common framework for creating these reports is that which is set out by the GRI, which has a framework outlining what needs to be included in the report in the economic, environmental, and social categories. That last category has several sub-categories, including labor practices and decent work, human rights, social and product responsibility.

In Option 2, the manufacturer must engage in sustainable leadership extraction practices. The credit requires project teams meet one of the recommended responsible extraction criteria for at least 25 percent—by cost—of the permanently installed products in the building. Acceptable responsible extraction criteria include recycled content, FSC certifications, and materials reuse, which have requirements that appear relatively consistent from previous versions of LEED.

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