Concrete, cement, and concrete masonry units

Concrete

Concrete is a composite material consisting of a mixture of hydraulic (e.g. portland) cement, aggregates, and water, with or without admixtures, fibers, or other cementitious materials. Concrete can be mixed at a job site, or “ready mixed” and batched for delivery from a central plant. Its wide-ranging applications include foundations, floors, walls, and roadways.

Construction product assemblies (such as rebar-reinforced concrete, or concrete made with qualifying cement) qualify for IRA funding if at least 80% of the assembly’s total cost or total weight comprises materials that meet these Requirements. Where provision of concrete that qualifies under these GSA IRA Limits is impractical, GSA’s IRA limits for cement may be applied to the cement being used in the concrete mix.

GSA IRA LEC material requirements

GSA IRA limits for low embodied carbon concrete

(EPD-reported GWPs, in kilograms of carbon dioxide equivalent per cubic meter — kgCO₂e/m³)

Add 30% to these numbers for GWP limits where high early strength¹ concrete mixes are required for technical reasons.

Compliance documentation

A product-specific Type III (third-party verified) Environmental Product Declaration that: (i) is based on the PCR used to develop these limits: NSF International’s Product Category Rule for Concrete (8/2021, version 2.1) [PDF]; and (ii) conforms with ISO 14025 and ISO 21930. Where feasible, EPDs must also rely on facility-specific data, including for the supply chain’s associated unit processes, such as concrete’s upstream cement plant, rather than industry or manufacturer average data. If an EPD containing facility-specific data for the material’s most greenhouse-gas intensive processes is unavailable, an EPD without such data that meets Compliance Documentation criteria (i) and (ii) is sufficient.

ENERGY STAR Energy Performance Score for supplying cement plant, the manufacturing plant name(s) and location(s), and the data period of the Energy Performance Score(s) at the time of purchase. For more information, please see ENERGY STAR Energy Performance Scores explained below.

Cement

Cement is the basic ingredient of concrete. Cement (including portland and portland-limestone cement) is manufactured through the chemical combination of ingredients including calcium, silicon, aluminum, and iron. When heated at high temperatures in kilns, some elements are driven off in the form of gases, while others unite to form a new substance called clinker. Clinker is cooled, ground, and mixed with small amounts of gypsum and limestone to make cement. When cement creates a paste with water that binds with sand and rock “aggregates” to harden, it forms concrete. Cement is transported to ready-mix concrete companies to be used in concrete for a wide variety of construction purposes.

GSA IRA LEC material requirements

Where provision of concrete that qualifies under these GSA IRA Limits is practical, GSA’s IRA Limits for Low Embodied Concrete must be used.

Where provision of concrete that qualifies under these GSA IRA Limits is impractical, GSA’s IRA Limits for cement may be applied to the cement being used in the concrete mix. A concrete EPD accounts for the whole mix design, including quantitative impacts of specific cements, aggregates, and admixtures. If a concrete EPD is provided to demonstrate compliance, a cement EPD doesn’t need to be submitted to GSA. Cement is an input to concrete mixes, and its GWP is accounted for in the concrete EPD.

Construction product assemblies can also qualify for IRA funding where at least 80% of the assembly’s total cost or total weight comprises IRA-qualifying material such as low embodied carbon cement.

GSA IRA limits for low embodied carbon cement

(EPD-reported GWPs, in kilograms of carbon dioxide equivalent per metric ton — kgCO₂e/t)

Compliance documentation

A product-specific Type III (third-party verified) Environmental Product Declaration (EPD) that: (i) is based on the PCR used to develop these limits: NSF International’s Product Category Rule for Portland, Blended, Masonry, Mortar, and Plastic (Stucco) Cements (9/2021, version 3.2; or 5/2020, version 3.0) [PDF]; and (ii) conforms with ISO 14025 and ISO 21930. Where feasible, EPDs must also rely on facility-specific data, including for the supply chain’s associated unit processes, rather than industry or manufacturer average data. If an EPD containing facility-specific data for the material’s most greenhouse-gas intensive processes is unavailable, an EPD without such data that meets Compliance Documentation criteria (i) and (ii) is sufficient.

ENERGY STAR Energy Performance Score for the cement plant, the manufacturing plant name(s) and location(s), and the data period of the EPS(s) at the time of purchase. For more information, please see ENERGY STAR Energy Performance Scores explained below.

Concrete masonry units

Concrete masonry units (CMUs) are standard-sized rectangular blocks used in building construction, sometimes referred to as cinder blocks. Other types of manufactured concrete can include concrete brick, concrete pavers and slabs, segmental concrete retaining walls, manufactured veneer stone, and concrete roof tiles.

GSA IRA LEC material requirements

GSA IRA limits for low embodied carbon concrete masonry units

(EPD-reported GWPs, in kilograms of carbon dioxide equivalent per cubic meter - kgCO₂e/m³)

Compliance documentation

A product-specific Type III (third-party verified) Environmental Product Declaration (EPD) that: (i) is based on a PCR for the applicable product category that was active when the EPD was issued, and which was used to develop these limits: ASTM International’s PCR for Precast Concrete (5/2021, version 3.0) [PDF] or UL’s Part B: Concrete Masonry and Segmental Concrete Paving Product EPD Requirements (3/2022, version 1.1); and (ii) conforms with ISO 14025 and ISO 21930. Where feasible, EPDs must also rely on facility-specific data, including for the supply chain’s associated unit processes, such as concrete’s upstream cement plant, rather than industry or manufacturer average data. If an EPD containing facility-specific data for the material’s most greenhouse-gas intensive processes is unavailable, an EPD without such data that meets Compliance Documentation criteria (i) and (ii) is sufficient.

ENERGY STAR Energy Performance Score for supplying cement plant, the manufacturing plant name(s) and location(s), and the data period of the Energy Performance Score(s) at the time of purchase. For more information, please see ENERGY STAR Energy Performance Scores explained below.

ENERGY STAR Energy Performance Scores explained

ENERGY STAR Energy Performance Scores show how efficiently a manufacturing plant uses energy on a 100-point scale. A score of 50 reflects average performance, 1 shows poor performance, and 100 reflects highest performance.

Contractors obtain Energy Performance Scores by requesting producers of cement, glass, asphalt mix, and steel (from integrated mills only) to provide the score. Or, contractors may request it from material suppliers (e.g. concrete producers).

Manufacturers of cement, glass and steel (from integrated mills only) produce a plant’s score by inputting 12 months of energy and production data in the industry-specific Energy Performance Indicator tool available at www.energystar.gov/epis. The score will show on the Statement of Energy Performance section of the EPI.

Energy Performance Scores can currently be produced for cement, flat glass, and integrated steel mills.

Footnotes

1. “High early strength” is concrete that, through the use of additional cement, high-early-strength cement, or admixtures, has accelerated early-age strength development. High early strength concrete produced using additional cement should be avoided where possible, due to its higher embodied carbon. An affected project delivery team must obtain written approval from GSA’s IRA PMO on whether high early strength concrete is necessary for technical reasons. This 30% allowance reflects input from building sustainability experts, general contractors, engineers, and ready-mix or cement producers.