Santa Monica City Council
April 23, 2024

Report/ July 2021
Reducing Embodied
Carbon in Buildings
Low-Cost, High-Value Opportunities
Authors
Rebecca Esau
Matt Jungclaus
Victor Olgyay
Audrey Rempher
Authors listed alphabetically. All authors from RMI unless otherwise noted.

Contacts
Victor Olgyay, [email protected]
Rebecca Esau, [email protected]
Copyrights and Citation
Matt Jungclaus, Rebecca Esau, Victor Olgyay, and Audrey Rempher, Reducing Embodied Carbon in Buildings: Low-Cost, High-Value Opportunities, RMI, 2021, http://www.rmi.org/insight/reducing-embodied-carbon-in-buildings.

RMI values collaboration and aims to accelerate the energy transition through sharing knowledge and insights. We therefore allow interested parties to reference, share, and cite our work through the Creative Commons CC BY-SA 4.0 license. https://creativecommons.org/ licenses/by-sa/4.0/.

All images used are from iStock.com unless otherwise noted.

Authors & Acknowledgments
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Acknowledgments
We would like to thank Skanska for providing material and cost information based on anonymized project data, and for conducting an EC3 analysis of the three case studies included in the report.

We would like to recognize the following members of the Skanska team for sharing key insights and reviewing the report:

Mark Chen
Steve Clem
Elaine Lai
Tolga Tutar
We thank the following individuals for their contributions to and review of the report:

Monika Henn, Urban Land Institute
Dirk Kestner, Walter P. Moore
Meghan Lewis, Carbon Leadership Forum
Marta Schantz, Urban Land Institute
We thank the following additional individuals and organizations for participating in interviews during the research phase of this report:

Arup
Bruce King, PE - Ecological Building Network
Thornton Tomasetti
Kieran Timberlake
Erin McDade, Architecture 2030
We thank Breakthrough Energy, LLC for its support in the production of this report.

About RMI
RMI is an independent nonprofit founded in 1982 that transforms global energy systems through market-driven solutions to align with a 1.5°C future and secure a clean, prosperous, zero-carbon future for all. We work in the world’s most critical geographies and engage businesses, policymakers, communities, and NGOs to identify and scale energy system interventions that will cut greenhouse gas emissions at least 50 percent by 2030. RMI has offices in Basalt and Boulder, Colorado; New York City; Oakland, California; Washington, D.C.; and Beijing.

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Reducing Embodied Carbon in Buildings www.rmi.org / 4
Table of Contents
Section 1 - Embodied Carbon: A Hidden Climate Challenge Executive Summary
What Is Embodied Carbon, and Why Is It Important?
The Time Value of Carbon
Lowering Embodied Carbon Can Drive Value
Setting the Stage
Section 2 - Key Materials Driving Embodied Carbon in US Buildings Industry Overview
Cement and Concrete
Steel
Timber
Insulation
Moving Forward
Section 3 - Proven Solutions and Strategies to Reduce Embodied Carbon Characterizing Low-Embodied-Carbon Solutions
Applying Low-Embodied-Carbon Solutions to the Design and Construction Process Current Tools for Implementation
Section 4 - Case Studies in the Economics of Low-Embodied-Carbon Buildings Overview
Methodology
Limitations of This Study
Case Study 1: Mid-Rise Concrete and Steel Construction
Case Study 2: Mid-Rise Stick-Built Construction
Case Study 3: Tilt-up Construction
Further Opportunities to Reduce Embodied Carbon in Case Study Buildings Discussion
Section 5 - Opportunities to Drive Deeper Savings
Regional Differences
Regional Data Disparity
Advanced Materials to Drive Greater Change
Codes and Policy
Section 6 - Conclusion
Appendix
Endnotes
5 6
7 7
7 8
9 10
11 12
13 13
14 15
16 17
19 20
21 22
23 24
25 26
27 28
30 31
33 34
38 39
41 43
Section 1
Executive Summary
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Embodied Carbon: A Hidden Climate
Challenge
Buildings account for at least 39% of energy-related
global carbon emissions on an annual basis.1 At least
one-quarter of these emissions result from embodied
carbon, or the carbon emissions associated with
building materials and construction. The solutions for
addressing embodied carbon in buildings have not
been widely studied in the United States, leaving a
significant knowledge gap for engineers, architects,
contractors, policymakers, and building owners.

Embodied carbon can be reduced significantly at
little to no additional up-front cost. The case studies showcased in this report show an embodied carbon
savings potential of 19%–46% at cost premiums
of less than 1%. Current practice indicates that
we can achieve these reductions by specifying
and substituting material alternatives with lower
embodied carbon during the design and specification
process. Far greater reductions are possible when a
whole-building design approach is taken.

This report highlights the low-cost and no-cost
solutions for reducing embodied carbon in buildings
by studying three building types and considering
design strategies that can reduce embodied carbon
at any stage of a project’s design and construction
phases. The report quantifies the construction cost
difference associated with low-embodied-carbon
solutions and points to next-generation solutions that
could drive even greater reductions.

Key Takeaways
• Up-front embodied carbon can be reduced by up
to 46% in our case study building typologies with
less than 1% cost premium.
• Optimizing ready-mix concrete design, choosing
finish materials with low-embodied-carbon
footprints, and considering low-embodied-carbon
or carbon-sequestering insulation options are the
most impactful no-cost measures for reducing
embodied carbon.
• Designing for minimal material usage can
reduce embodied carbon, lower up-front costs,
and maintain a building’s sound structure and
aesthetics.
• Sourcing rebar and structural steel with higher
recycled content, choosing low-embodied-carbon
glazing products, and reducing structural system
material needs are the most impactful low-cost
measures.
• Currently emerging materials promise to
significantly further reduce embodied impacts.

Executive Summary
Exhibit 1 Top categories for reducing embodied carbon
Rebar
Use high recycled
content rebar
4%–10% reduction
None to low cost premium
Insulation
Select low- or
no-embodied-carbon
insulation products
16% reduction
No cost premium
5% reduction
Finish Materials
Select low- or
no-embodied-carb
on finish materials
None to low cost premium
Optimize
concrete mix
14%–33% reduction
None to low cost premium
Concrete
3% reduction
Select lowembodied-carbon
glazing products
10% cost premium
Glazing
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What Is Embodied Carbon, and Why Is It
Important?
Embodied carbon refers to the greenhouse gas
emissions resulting from extracting, manufacturing,
and installing materials and products over the life
cycle of a building.2 These emissions can also include
the use phase and treatment of materials at the end
of their useful lives (e.g., reuse, recycling, landfilling).

It’s critical to understand which life-cycle stages are being considered in any study of embodied carbon.

The most common characterizations are “cradle to
gate” (covering material extraction, transportation,
and manufacturing) and “cradle to grave” (which also
includes the use phase and end-of-life considerations).

End-of-life considerations are important for
developing a holistic and consistent view of the
environmental impacts that a material has through its
disposal or reuse. However, end-of-life considerations
are often omitted due to data scarcity, uncertainty
about eventual treatment (will a product be landfilled, recycled, or reused?), or other unknowns.

This report will only consider the cradle-to-gate lifecycle stages, or up-front embodied carbon. These stages correspond to the A1–A3 life-cycle stages
that are commonly used for life cycle analysis,3
which refer to raw material supply, transport to the
manufacturing site, and manufacturing. Up-front
embodied carbon includes emissions related to the
extraction, transportation (from extraction site to
manufacturing site), and manufacture of materials. It
does not include emissions related to transportation
to the construction site, the construction or use
phases, or end-of-life considerations. Therefore,
the core conclusions and case study analysis in this
report do not address end-of-life embodied carbon
considerations, although the report does discuss endof-life considerations at a high level.

Embodied carbon is critical for climate mitigation
because it accounts for upward of 11% of global
emissions4 (up to 23% by some estimates),5 but it
has not been addressed at nearly the same scale
as operational emissions (the emissions associated
with energy consumption). As global construction
continues to rise, and existing building operations
become more efficient, embodied carbon will become
an increasingly significant issue—accounting for
approximately 50% of global building-sector emissions
between now and 2050. This growing problem will
account for a significant amount of our remaining
carbon budget for keeping global warming below

1.5°C, and it needs to be addressed by policymakers
and practitioners now to drive the most impact.6
The Time Value of Carbon
In the quest to reduce the emissions generated
from building construction and operations, the most
valuable opportunity for reducing carbon is at the
beginning of a building's life. Embodied carbon is
critical to mitigating global climate change, because
most of these emissions typically occur up front, at
the start of a building’s life cycle. Architecture 2030 reports that “[u]nlike operational carbon emissions,
which can be reduced over time with building energy
efficiency renovations and the use of renewable
energy, embodied carbon emissions are locked in
place as soon as a building is built. It is critical that we get a handle on embodied carbon now if we hope to
phase out fossil fuel emissions by the year 2050.”
Global construction is booming and is projected to
continue to rise for decades.7 It is therefore critical to reduce embodied carbon emissions as quickly as
possible, because the emissions from construction
today can remain in the atmosphere for hundreds
of years. Reducing and avoiding both embodied and
operating emissions is our best strategy for reducing
the overall quantity of CO2e in the atmosphere.

Lowering Embodied Carbon Can
Drive Value
Embodied carbon reductions can deliver value beyond
reducing carbon emissions.

Embodied carbon reductions can often reduce project
costs. Reducing the amount of material needed in a
Reducing Embodied Carbon in Buildings www.rmi.org / 8
project is one of the first steps that building designers can take to reduce embodied carbon. Procuring
fewer materials will cost the owner and developer
less money. Further, carbon-reduction strategies that
reduce the cement content of many concrete mixes
can also reduce cost, as cement is a driver of both cost and carbon for concrete. Projects that use mass timber
for structural components also reduce project costs
due to faster construction times with more modular
components and simpler connections.

Low-embodied-carbon products also often reduce
energy consumption in extraction, manufacturing,
and/or transportation. Unless their process is
driven by carbon-intensive chemical reactions, lowembodied-carbon products will, by nature, result in energy savings upstream of a material’s end use.

These savings typically result in operational cost
savings for material manufacturers, which may be
passed on to the end consumer.

Building projects that reduce embodied carbon and/
or include a whole-building life cycle assessment
(WBLCA) can help to meet green building
certification requirements. Certifications that
incorporate embodied carbon include the Building
Research Establishment Environmental Assessment
Method (BREEAM), Excellence in Design for Greater
Efficiencies (EDGE), LEED v4 from the U.S. Green
Building Council, and both the Zero Carbon and
Living Building Challenge certifications from the
International Living Future Institute (ILFI).8
A low-embodied-carbon building design will also be
better prepared for future code or policy changes
that incentivize or require low embodied carbon.

In the near term, these changes could take the
form of a carbon tax, building code requirements,
procurement policies (e.g., Buy Clean policies),
development incentives, or other regulatory
mechanisms. Although localities are unlikely to
implement retroactive policies requiring lowembodied-carbon building design, building to a lowembodied-carbon standard will prepare developers, designers, and the construction industry for these
likely future scenarios.

Finally, reducing emissions in the extraction,
manufacturing, and transportation of low-embodiedcarbon materials improves air quality and public health in communities located close to industrial
centers. These health and environmental benefits
are especially important for communities of color,
including Black, Latinx, and Indigenous communities
and people in areas with lower incomes, who are most
directly impacted by industrial emissions through
higher rates of asthma and other diseases.9
Setting the Stage
This report will lay out a framework for reducing
embodied carbon in buildings and highlight the ways
that the construction industry can cost-effectively
reduce embodied carbon in some of the most
prevalent building construction types in the United
States today.

Section 2
Key Materials Driving Embodied
Carbon in US Buildings
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Industry Overview
In order to tackle embodied carbon in buildings and
initiate a sector-wide shift toward addressing the
issue, we first need to understand the carbon impact
of the industries driving embodied carbon emissions.

WBLCAs show us that a building’s structure and
substructure typically constitute the largest source of its up-front embodied carbon, up to 80% depending
on building type.10 However, because of the relatively
rapid renovation of building interiors associated with
tenancy and turnover, the total embodied carbon
from interiors can account for a similar amount of
emissions over the lifetime of a building. In this report, we focus primarily on structural materials, metals
(including steel and aluminum), cement, insulation,
and timber. Each of these materials has a different
embodied carbon content but is critical to our
consideration of structural systems in this context.

We can better understand the carbon embodied in
buildings by looking at these materials individually:
cement and concrete, steel, timber, and insulation.

Key Materials Driving Embodied
Carbon in US Buildings
Typical high-embodied-carbon structural elements, building envelope materials, and finish materials
Exhibit 2
Source: Mithun
Rigid Insulation
Beams + Columns
Floor + Roofs
Ceiling Tile

1. Structure

3. Finishes

2. Building Envelope
Carpet
Gypsum Wall Board
Metal Panels
Glass
Precast Panels
Aluminium Mullions
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Cement and Concrete
Concrete is one of the most widely used materials
in the construction industry and a primary source
of embodied carbon in buildings. In fact, global use
of concrete exceeds the consumption of any other
material, aside from water.11 Although each of concrete’s constituent materials offer opportunities for reductions in embodied carbon, the high embodied carbon of
concrete is primarily driven by the manufacture of one
key ingredient—ordinary portland cement. Portland
cement is the most common cementitious binder used
in concrete mixtures in the United States, and the US
cement industry is one of the largest contributors to
US-borne emissions at 68.3 million metric tons (MMT) of CO2e per year.12
While the layperson may use “cement” and “concrete”
interchangeably, they are unique materials, and
understanding the difference is key to the embodied
carbon discussion. To build a building, construction
professionals buy concrete (which contains cement), not the cement itself. Cement is used with water as a binder to adhere particles of sand and rock (aggregate) together to form concrete. The manufacture of cement tends to
be centralized, and the mixing of cement into concrete
is highly localized to minimize the expense of moving
heavy aggregate.

Nearly 60% of CO2
emissions from cement production
come from chemical reactions that occur while
producing clinker, an intermediary component
of cement.13 Since these emissions are the result
of chemical reactions, they cannot be reduced or
eliminated by increasing energy efficiency or by
switching fuels. As such, one way to reduce the
embodied carbon content of cement is by replacing a
portion of the cement with supplementary cementitious
materials (SCMs) such as fly ash and slag or by using a clinker-free alternative to portland cement.

However, SCMs are in high demand due to their ability to reduce the embodied carbon of cement and concrete,14
and some SCMs are becoming less widely available.

For instance, supply of fly ash, a by-product of coal
power generation, is falling as coal is used less and less as a power generation source. High-quality aggregate
can also reduce the amount of cement needed to
produce concrete due to better adhesion and other
properties. In some cases, it can even be worthwhile to import aggregate, as the improved strength properties
can outweigh the carbon emissions associated with
transportation.15
The remaining 40% of cement production emissions
come from the burning of fossil fuels to heat the kilns required to produce clinker. The electrification of cement production, as well as the use of alternative fuels such as biomass and renewable energy, could help reduce
emissions, but these strategies are currently in early
stages of development and adoption. Researchers
are exploring carbon capture techniques that would
capture and store carbon emissions from the cement
kilns as a potential solution, but these technologies
are not market-ready. Because emissions associated
with cement are so significant (almost 1 kg of CO2
for
each kg of cement manufactured), many researchers
are working on emerging technologies to address this
issue.16 Today’s technologies can help manufacturers
make cement products with substantially less emissions
at competitive prices, and emerging technologies may
be able to produce zero-embodied-carbon cement, or
even net carbon-negative products.17
The building construction industry’s demand for
concrete accounts for an estimated 51% of total portland cement produced in the United States.18 Given its
evident popularity in building construction, it’s essential we address the high carbon intensity of this material.

A forthcoming guide by RMI outlines how concrete
ready-mix suppliers, developers, and contractors can
leverage proven and cost-effective solutions to lower the embodied carbon of concrete.

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Steel
The US steel industry is responsible for 104.6 MMT of
CO2 emissions annually, a contribution that makes up
2% of total US emissions.19 Steel industry emissions have dropped by approximately 60% since 1990, largely due
to technological improvements as well as increased
recycling of scrap steel.20 Even so, steel is a substantial source of embodied carbon emissions for the built
environment that could theoretically be reduced to zero either through material substitution or through the
production of cleaner steel.

In recent decades, the US steel industry has shifted away from the use of integrated steel mills and the primary
use of blast oxygen furnaces, toward the use of more
efficient electric arc furnaces (EAF), which use scrap steel as a primary input. Of all the US steel made in 2016, 70% was manufactured using efficient electric arc furnaces,21 reflecting a switch that has indeed reduced the carbon
footprint of steel. However, steel production remains an incredibly energy intensive process, and steel destined for the built environment is still responsible for 46 MMT of CO2 emissions annually,22 because EAFs are effectively as “clean” as their energy source.

The most straightforward way to reduce embodied
carbon for structural steel today is to specify steel
produced in facilities that operate using relatively lowemissions (or zero-emissions) energy sources such as hydroelectric, renewable hydrogen, solar, or wind.23
Although zero-carbon steel may not be market-ready
today, specifying steel produced in efficient factories will ensure less energy is used in production. In
combination with cleaner electricity, this step can make a significant difference.24
Structural steel is the predominant structural framing
material used in building construction, holding 46% of
the market share for structural framing materials for
nonresidential and multistory residential construction
in 2017. Concrete and wood held 34% and 10% of the
market share, respectively.25 Steel reinforcing or “rebar,” which is typically embedded in structural concrete, can also be a major use of steel.

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Timber
Timber has been used in building construction for
thousands of years and is still one of the most widely
used building materials. In 2017, building construction accounted for 62% of wood product end use in the
United States. Although conventionally used for
construction of single-family houses and low-rise
buildings, wood is attracting interest worldwide for
the construction of taller buildings as wood products
become an effective alternative to more carbonintensive concrete and steel.

With the introduction of innovative design strategies
and engineered wood products such as cross-laminated
timber (CLT), wood is steadily becoming a more viable
material option for low- and mid-rise buildings. The
cost-effectiveness of wood products has helped drive
interest as costs of steel and concrete rise, and wood
products offer additional benefits for design flexibility, construction speed, and reduced environmental impact.

Although CLT is not yet widely used in the United States, the wood-framed “podium” building design, which
includes several stories of wood over one story of
concrete, is gaining in popularity.

Timber could even be considered a net carbonsequestering material, because the carbon sequestered during a tree’s growth can surpass the carbon emitted
during harvesting and manufacturing. However, this
determination depends on the method of cultivation
and harvest as well as the end-of-life considerations
of the material. Considering wood as a carbonsequestering material is a point of contention among industry experts, with debate largely revolving around
varying forestry and harvesting practices and their
effect on emissions. Nevertheless, timber is typically
seen as a lower-carbon alternative to steel and concrete when used as a structural material.

In order to fully understand the impact of timber
materials, environmental assessments must first
account for variation in forest management and
harvesting practices, because differences in these
practices produce great disparities in the amount
of carbon sequestered. For example, the Forest
Stewardship Council (FSC) certifies that wood
products are responsibly and sustainably produced,
and specifying FSC-certified products is a positive
step toward managing low-carbon wood products.26
However, FSC is not the only source of sustainably
harvested wood, and groups that do not pursue
certification can also have excellent forest management practices. When wood is not harvested sustainably,
the resulting ecological destruction, increased soil
degradation, and use of petroleum-based fertilizers can drastically increase the embodied carbon content of
wood products.

As demand grows for wood products, it will be crucial
to ensure this demand is met with sustainable forestry
management practices. Otherwise, the broader use
of timber as a building product could result in higher
carbon emissions and less ecological diversity.27
Insulation
Insulation products are essential to creating operationally efficient buildings. Although they may represent a relatively small portion of an overall construction cost budget, they can be a significant contributor to a building’s embodied carbon budget. This category of materials has products
with a broad range of embodied carbon impacts, from
carbon-intensive, petrochemical-based contributors to
carbon-negative options. For example, rigid or spray foam products have the greatest associated emissions, whereas biological-based materials (such as cellulose and cotton products) can contribute very little embodied carbon or even be considered as net carbon-sequestering products.

The insulative capacity of a product, measured as thermal resistance, or R-value, varies between material type,
with high values indicating higher performing insulation.

Biological-based materials tend to have lower R-values
than carbon-intensive materials and would require a
thicker application of the product to achieve an equivalent level of performance. Exhibit 3 demonstrates the relative up-front embodied carbon emissions associated with
various insulation materials.

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Moving Forward
Although embodied carbon reduction strategies exist
today, there are several significant barriers to achieving these reductions. Perceptions of high cost, along with
industry resistance to change, have stifled progress.

Misinformation and low product availability have
contributed to misconceptions that low-embodiedcarbon products are more complicated to use or procure, or that they are inferior in strength or quality.

Additionally, most industry decision makers and
developers remain unaware of the embodied carbon
discussion and therefore do not know to request these
products to begin with, or they might not be aware of
tools that can help them identify and track their project’s emissions. Structural engineers, architects, and other
specifiers could significantly reduce embodied carbon in new construction projects at little to no additional cost by using the tools and resources available to them today, detailed in Section 3.

There are many more materials and construction
methods that can deliver substantial carbon reductions
in buildings beyond what is covered in this report. The processes, solutions, and case studies offered in the
following sections can help developers, designers,
and construction professionals achieve low embodied
carbon in buildings based on today’s best practices.

Embodied carbon of insulation materials (kg CO2 Exhibit 3 e) 3,319 Cellulose
Fiberglass 2,053
Mineral Wool 4,730
Closed Cell Sprayfoam (HFC) 17,518
Closed Cell Sprayfoam (HFO) 9,948
22,312 Straw Bale
18,257 Hempcrete
Expanded Polystyrene (EPS) 2,517
Extruded Polystyrene (XPS) 20,205
Net Carbon Emitting
Net Carbon Sequestering
Source: Chris Magwood, Opportunities for CO2 Capture and Storage in Building Materials, 10.13140/RG.2.2.32171.39208, 2019.

Note: The amount of CO2e is based on R-20 at 234 m2.

Section 3
Proven Solutions and Strategies to
Reduce Embodied Carbon
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Proven Solutions and Strategies to
Reduce Embodied Carbon
Building a common understanding of solutions
and strategies to reduce embodied carbon in
buildings is a critical first step to testing the
economic value and technical potential of lowembodied-carbon construction.

Characterizing Low-Embodied-Carbon
Solutions
Today, there are many solutions that can be leveraged
to limit embodied carbon in new buildings. The totality of low-embodied-carbon solutions includes a long list
of offerings that span a wide range of complexity.

Most simply, low-embodied-carbon solutions for
buildings can be broken down into three main
categories: whole-building design, one-for-one
material substitution, and specification. In general,
whole-building design solutions can drive the
greatest embodied carbon savings. However, material
substitution and specification can also result in
substantial embodied carbon savings, especially when
these solutions target carbon-intensive materials such
as concrete and steel. Furthermore, these categories
are not mutually exclusive—they can be combined
or performed in parallel to drive deeper embodied
carbon savings.

The examples corresponding with each strategy
barely scratch the surface of possible low-embodiedcarbon solutions.

As the world becomes more fluent in low-embodiedcarbon construction, new design strategies may prove themselves more impactful, some materials may be
produced more efficiently, and architectural styles may shift—all changing the calculation around designing for low embodied carbon.

Whole-building design
Initial decisions that affect the fundamental design of a building to reduce embodied carbon while meeting the
functional requirements of the project.

These strategies include adaptive reuse of an existing
building, reducing the overall square footage of a project, using more efficient structural systems or alternative building techniques, using prefabricated systems or components, and designing to minimize waste.

Example
Minimizing the overall quantity of material used in a building, especially high-embodied-carbon materials such as concrete, steel, and petrochemical-based insulation products, can significantly reduce the overall embodied carbon of a project.

Impact
Designing for additional levels of structural efficiency and material savings can yield “compounding efficiency,” where lighter structures reduce material quantities as well as requirements for foundations. This can directly result in material cost savings.

Key Considerations
Tracking embodied carbon in terms of kilograms of CO2e
per square foot is key to quantifying the benefit of material quantity reductions. Structural engineers often design for efficiency automatically based on economics, but because they work within the framing scheme shared by the architect, engineers and architects need a collaborative approach to achieve deeper savings.

One-for-one material substitution
Direct replacement of one material with another that will meet the functional requirements of the original design while having a lower global warming potential (GWP).

Example
Choosing cellulose as an insulating material in place of a petroleum-based insulation (e.g., expanded polystyrene) can achieve the same functional need (insulation) while dramatically reducing the embodied carbon of the overall project.

Impact
In some cases, insulation products can lead to near-zero or net negative (sequestering) carbon emissions.

Key Considerations
When considering two materials, it’s important to consider their functional performance. For insulation products, this includes their thermal properties (e.g., R-value) as well as their form factors (e.g., blown product, rigid board, batt) and other performance qualities (whether they also provide an air barrier, resist fire, repel pests, etc.).

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Applying Low-Embodied-Carbon Solutions
to the Design and Construction Process
The most effective path to reducing cost and carbon on
a building construction or renovation project is to set embodied carbon goals and perform analyses early in
the design process. The initial prioritization of embodied carbon will enable the design team to consider wholebuilding design solutions, which can yield substantial reductions in embodied carbon. It’s important that
design solutions are established early in the process
because it becomes more difficult and expensive to
make fundamental changes as the project becomes
more definite.

Other interventions, such as material replacement and
specification, naturally occur later in the design process when the project is more defined. Substituting and
specifying low-embodied-carbon materials alone can
have significant impact on the embodied carbon of a
construction or renovation project.

Strategies to reduce embodied carbon exist for
every stage of the design process, from predesign
and site selection through occupancy (see Exhibit
4). Implementing these strategies falls under the
responsibility of numerous stakeholders and requires
a level of collaboration beyond standard practice. To
foster the strong working relationships needed to
execute these strategies, it is critical that the project owner bring together the architect, engineer, energy
or sustainability consultant, contractor (if possible), and other major stakeholders at the outset of a
project to establish roles and responsibilities and
set frequent check-ins throughout the design and
construction process.

Specification
Establishing a value or limit for a material characteristic that will dramatically reduce embodied carbon content.

Example
A designer can specify a desired percent reduction of GWP in a given concrete mix. To meet this demand, the manufacturer could incorporate changes to the concrete mix design that reduces embodied carbon while meeting the necessary
strength requirements. These changes may include lowering the ratio of portland cement, incorporating supplementary cementitious materials (SCMs), or using aggregate that will result in lower total embodied carbon.

Impact
Cement often drives the embodied carbon of a given concrete mix, and lowering its content will reduce the carbon impact of the project.

Key Considerations
Reducing portland cement content may lead to notable
changes in process, such as longer cure times for a given cement mix. Note that for a given material choice, the
design team can use open-source tools such as EC3 or other databases (see page 19 for more information on these
resources) to identify the lower-carbon, cost-comparable option for their project. Some suppliers may not have
environmental product declaration (EPD) data displaying the embodied carbon content of the material to prove it has a lower embodied carbon content than standard products.

These data limitations are expected to improve as demand grows for low-embodied-carbon materials.

Strategies to reduce embodied carbon throughout the design and development process
Exhibit 4
Predesign &
Site Selection
1 Conceptual &
Schematic
Design
2 Design
Development
& Construction
Documents
3 Bidding &
Procurement
4 Construction
5 Occupancy:

Maintenance,
Renovations &
Tenant Fit-Outs
6 Primary Roles
Consider reusing an existing building before deciding to design a new building.

Assess soil type and determine options for the building’s foundation. Some types of foundations use greater quantities of materials than others.

Consider salvaging or reusing materials from a building that is to be deconstructed.

Set an embodied carbon budget for the project based on LCA calculations for similar buildings or case studies.

Ensure structural systems are compact, efficient, and not oversized.

Design flexible and efficient spaces that allow for long-term changes in use.

Design for future disassembly and reuse.

Consider the embodied carbon trade-offs related to architectural design decisions such as massing, envelope systems, foundations, and landscaping.

Conduct an initial whole-building LCA (WBLCA) or perform an LCA for “hot spot” materials or assemblies with higher carbon intensities.

Select building systems and assemblies that minimize embodied carbon.

Assess availability of local reused and locally sourced materials.

Specify material characteristics that result in low embodied carbon.

Substitute like-for-like materials that offer lower global warming potential Consider the embodied carbon trade-offs related to architectural and structural refinements and changes.

Update WBLCA as needed.

Incorporate clear embodied carbon goals in all procurement language and set building system or material-specific goals.

Include requirements for product substitutions in the specifications.

Request embodied carbon data, including EPDs, from all vendors.

Include previous work, experience, and proposed solutions that address embodied carbon in any procurement selection criteria.

Design a subcontractor selection process that incentivizes bidders to offer lower-embodied-carbon materials and methods.

Establish clear guidelines and targets to reduce construction waste.

Hold contractors accountable for delivering low-embodied-carbon design committed to in previous phases.

Consider offering monetary performance bonuses for additional embodied carbon reductions identified and executed during the construction process.

Document the as-built embodied carbon content of the building and publish the data.

Update WBLCA as needed.

Debrief and apply lessons learned to future projects.

Establish embodied carbon reduction targets for future
renovations and tenant fit-outs.

WholeBuilding
Design
Material
Substitution
Specification &
Procurement
Architect Contractor Manufacturer Owner Structural Engineer Geotechnical Engineer Landscape Architect Source: Partially adapted from Embodied Carbon Quick Guide: A Quick Reference Guide for Teams to Reduce their Project’s Embodied Carbon, International Living Future Institute, 2020.

Reducing Embodied Carbon in Buildings www.rmi.org /19
Current Tools for Implementation
A number of open-source and subscription-based
tools are available to support low-embodiedcarbon design and construction strategies. The following tools can be used to assess and reduce the
environmental impact of projects:
• The Athena Impact Estimator for Buildings is a
free software tool for conducting a comprehensive
life cycle assessment of buildings. It draws on an
embedded database of regionally specific material
life-cycle data. The tool allows for side-by-side
comparisons providing clear visibility into the
impacts of various design choices.
• The Carbon Smart Materials Palette is an
Architecture 2030 project that provides “attributebased design and material specification guidance” intended to connect designers and specifiers with
information about key materials and actionable
information about how to reduce embodied carbon
during the design and construction process.28
• The Embodied Carbon in Construction
Calculator (EC3) is an open-source database that
houses thousands of digitized, third-party verified
Environmental Product Declarations (EPDs). This
tool is most useful in providing transparency of
information and comparing the carbon impact of
different product options across similar material
types. EC3 also allows users to compare the
up-front (A1–A3) embodied carbon impacts of
different building materials for a given project, but
it is not intended as a WBLCA tool.
• One Click LCA is a subscription-based software
product that integrates with building information
modeling (BIM) and an extensive database of
material EPDs to produce a life cycle assessment
in any design stage of a project.
• Tally is an application that allows architects and
engineers to perform highly detailed WBLCAs of
projects directly within the Revit design platform.

Redevelopment and Reuse
When embarking on a building project, the first
consideration should be whether new construction
is needed at all.29 The embodied carbon impact
of redeveloping an existing structure is 50% to
75% lower than the impact of constructing a new
building.30 By repurposing existing assets, both cost
and carbon emissions associated with new building
materials are avoided. Even if the foundation and
structure are the only elements retained, their reuse
will have a significant impact on the embodied carbon
of the project, because these components generally
account for a majority of a building’s carbon footprint.

If redeveloping an existing building is not a viable
option, consider incorporating recycled materials into
the design wherever possible. It is also important
to design with the end of the building’s life in mind,
ensuring the systems can be easily deconstructed and
reused or that the building can be easily reconfigured
to fill another use.

The following section presents case studies that
apply a number of low-embodied-carbon solutions
to achieve substantial embodied carbon reductions
at less than 1% additional cost.

Section 4
Case Studies in the Economics of
Low-Embodied-Carbon Buildings
Reducing Embodied Carbon in Buildings www.rmi.org / 21
Overview
One of the core objectives of the report is to answer
the question: How much can we reduce embodied
carbon in new buildings at no additional cost?
In short, this study shows that embodied carbon
can be reduced by 19%–46% in mid-rise commercial
office, multifamily, and tilt-up-style buildings by
leveraging low- and no-cost measures. Together,
these measures increased overall project costs by
less than 1%, which is within the margin of error for
most construction project budgets.

Skanska, one of the world's leading sustainable
construction firms, provided cost data from
three actual projects in the Pacific Northwest and
conducted an analysis under the guidance of RMI to
generate the results of this study.

Case Studies in the Economics of
Low-Embodied-Carbon Buildings
Exhibit 5 Methodology and assumptions for the report's case study modeling exercises Reducing Embodied Carbon in Buildings www.rmi.org
/ 22
Methodology
Skanska and RMI chose the three building
construction types included in this study based on the
most significant building use types that exist in the
United States today by gross square footage.31 This
includes buildings with a steel-reinforced concrete
slab and steel and concrete above grade (case study
1), buildings with a steel-reinforced concrete slab and traditional timber framing above grade (case study 2),
and buildings with tilt-up construction (case study 3).

Case studies 1 and 2 are representative of traditional
mid-rise office and multifamily residential buildings,
whereas case study 3 represents a construction
methodology commonly used for big-box retail,
warehouses, and data centers.

Skanska chose three representative buildings of
these construction types from its recent construction
portfolio. As a full-service design, cost estimation,
and construction firm, Skanska was able to produce
quantity takeoffs and cost estimates for each of
these buildings. Skanska combined the quantity
takeoff information for these three projects
with environmental performance data from the
Embodied Carbon in Construction Calculator (EC3)
tool to develop a high-level estimate of the up-front
embodied carbon associated with constructing the
structural systems, insulation, glazing, and interior
finish materials within each existing building design.

The original cost and quantity takeoff information,
combined with the up-front (cradle-to-gate, or A1–A3)
embodied carbon data from EC3, established our
baseline case.

Skanska then modified each of these baseline
buildings to develop a “cost-effective embodied
carbon reduction” scenario. The main methodology
for this scenario was to select materials that represent the 80th percentile of carbon dioxide equivalent
established in available environmental product
declarations (EPDs) for the chosen material. EPDs
are essentially independently verified product labels
that approximate embodied carbon and other
environmental impacts. Skanska’s methodology
focused on one-for-one material substitution and
specification strategies, as performing whole-building
Reducing Embodied Carbon in Buildings www.rmi.org / 23
design changes would be difficult to reflect in the
models. Then, Skanska performed a cost analysis to
either affirm that the chosen material would have
no attributable cost increase, or to calculate a cost
premium for the chosen material. The materials that
were chosen for this “cost-effective” scenario were not to increase total project cost by more than 1%.

RMI and Skanska also intended to include additional
embodied carbon reduction measures that would
drive deeper whole-building embodied carbon
reductions. Many of the measures in this category
are under development or not widely available in the
United States; others could not be accurately costed.

As a result, these advanced material solutions are not
included in the scenarios below but are addressed
qualitatively in section 5.

Limitations of This Study
Ideally, this study would incorporate data from
thousands of projects across the United States. Such
a sample would provide a diversity of cost estimates
from construction firms, an understanding of regional
variation in pricing and availability, and a statistically significant sample of costs and quantity takeoffs.

The data and the assertions made in this study
are based on the scenarios that RMI and Skanska
studied. However, they cannot be generalized to all
building typologies, or across every building project,
because they were not drawn from a statistically
significant sample, nor are these construction use
types perfectly representative of their respective
construction types.

Additionally, the case studies only address up-front
embodied carbon, which considers life-cycle stages
A1–A3 (extraction, manufacturing, and transportation
between those processes), or a cradle-to-gate system
boundary. The case studies do not consider the
emissions related to construction, use, or the end of
a product’s life (including any of the considerations in life-cycle stages A4–A5, B, C, or D).

Finally, this study does not include any whole-building design strategy changes. Although these strategies
(e.g., redesigning a building to use different or fewer structural materials) can often achieve significant
reductions at low cost, the scope of this project
limited our analysis to use of the EC3 tool. EC3 can
readily make specification and one-for-one material
substitution comparisons, but it does not have the
capability to inform whole-building design changes.

The following case studies detail our key findings for
each construction use type.

Reducing Embodied Carbon in Buildings www.rmi.org / 24
Case Study 1: Mid-Rise Concrete and Steel Construction
In a five-story, 200,000 ft2, mixed-use office building with a steel-reinforced concrete slab and steel and concrete above-grade construction, we identified a potential 46% reduction in up-front embodied carbon by focusing on a wide array of building components. The cost premium for this reduction in embodied carbon is less than 0.5% of the overall project cost.

Structural systems
Glazing
Roofing
Interior wall materials (unfinished)
Insulation
46% < 0.5% 2,228
Of Total Budget
Up-front embodied carbon
reduction from baseline
Cost premium of lowembodied-carbon
measures
CO2
e reduced
(metric tons)
Building components in
scope
Top no-cost measures (measures that do not add to total project cost) Specify lower-embodied-carbon products:

Ready-mix concrete: optimize ready-mix supplier award selection, procure lower cement mix designs, and allow for 56-day strength obtainment Metal decking
Roofing
One-for-one material substitution:

Gypsum sheathing
Insulation materials: procure lower-embodied-carbon insulation products such as polyiso or mineral wool batt in lieu of materials with higher GWPs, such as XPS
Top low-cost measures (measures that have a small cost premium associated with lower-embodied-carbon alternatives) Specify lower-embodied-carbon products:

Glazing: procure lower-embodied-carbon glazing products Structural steel and rebar: strategically procure steel from mills that incorporate high recycled content steel, electric arc furnace technology, and clean electrical supply
Steel Proposed (excl rebar)Baseline Concrete Rebar Glazing Insulation











Embodied Carbon Reduction by
Material Category




Reducing Embodied Carbon in Buildings www.rmi.org / 25
Case Study 2: Mid-Rise Stick-Built Construction
In a six-story, 125,000 ft2, mixed-use multifamily building with lumber framing above a steel-reinforced concrete slab, we identified a potential 41% reduction in up-front embodied carbon by focusing on a wide array of building components. The cost premium for this reduction in embodied carbon is less than 0.5% of the overall project cost, in line with the results of case study 1.

Steel Proposed
(excl rebar)
Flooring/ Glazing Doors
Paint
Baseline Insulation Concrete Rebar


















Embodied Carbon Reduction by
Material Category
Structural systems
Glazing
Roofing
Interior wall materials
Insulation
Wall/floor finish materials
41% < 0.5% 1,482
Of Total Budget
Up-front embodied carbon
reduction from baseline
Cost premium of lowembodied-carbon
measures
CO2
e reduced
(metric tons)
Building components in
scope
Top low-cost measures (measures that have a small cost premium associated with lower-embodied-carbon alternatives) Specify lower-embodied-carbon products:

Glazing: procure lower-embodied-carbon glazing products Structural steel and rebar: strategically procure steel from mills that incorporate high recycled content steel, electric arc furnace technology, and clean electrical supply
Top no-cost measures (measures that do not add to total project cost) Specify lower-embodied-carbon products:

Ready-mix concrete: optimize ready mix supplier award selection, procure lower cement mix designs for foundation and basement, and allow for 56-day strength obtainment
Moisture barrier: choose lower-embodied-carbon products Wood: procure locally produced and sustainably sourced wood products, including structural wood and sheathing products Gypsum sheathing: procure lower-embodied-carbon gypsum sheathing products Insulation materials: procure lower-embodied-carbon insulation products such as polyiso or mineral wool batt in lieu of materials with higher global warming potential (GWP), such as XPS
Interior and fit-out: choose interior finish and fit-out products with lower embodied carbon content, including interior and exterior doors, carpet tiles, paints, and interior walls
One-for-one material substitution:

Reducing Embodied Carbon in Buildings www.rmi.org / 26
Case Study 3: Tilt-Up Construction
In a 360,000 ft2 tilt-up concrete warehouse, we identified a potential 19% reduction in up-front embodied carbon by focusing on shell and core materials only. The cost premium for this reduction in embodied carbon is less than 1% of the project cost—a slightly higher premium as compared with case studies 1 and 2 but still within the margin of error for most construction projects.

Steel Proposed (excl rebar)Baseline Concrete Rebar Gypsum












Embodied Carbon Reduction by
Material Category
Shell and core materials only:

Concrete
Rebar
Structural steel
Metal decking
Glazing
Metal panels
Roofing
Gypsum sheathing 19% < 1% 2,501 Rigid insulation Of Total Budget Up-front embodied carbon
reduction from baseline
Cost premium of lowembodied-carbon
measures
CO2
e reduced
(metric tons)
Building components in
scope
Top no-cost measures (measures that do not add to total project cost) Specify lower-embodied-carbon products:

Insulation materials: procure lower-embodied-carbon insulation products such as polyiso or mineral wool batt in lieu of materials with higher GWP, such as XPS
Ready-mix concrete: optimize ready mix supplier award selection, procure lower cement mix designs for foundation and basement, and allow for 56-day strength obtainment
Top low-cost measures (measures that have a small cost premium associated with lower-embodied-carbon alternatives) Specify lower-embodied-carbon products:

Glazing: procure lower-embodied-carbon glazing products Structural steel and rebar: strategically procure steel from mills that incorporate high recycled content steel, electric arc furnace technology, and clean electrical supply
Reducing Embodied Carbon in Buildings www.rmi.org / 27
Interior Fit-Out
Although it is commonly understood that the structure
of a typical building accounts for the majority of
the building’s up-front embodied carbon footprint,
examining the recurring cycle of renovation over a
building’s life reveals the importance of interior finish materials.

In some cases, the cumulative impacts of multiple
renovation cycles can surpass the up-front embodied
carbon accumulated during a building’s construction.32
A recent report from architecture and design firm
Hawley Peterson Snyder conservatively estimated
that building interiors are renovated or replaced on a
15-year cycle, adding to the building’s total embodied
carbon each time.33 In cities with high frequency of
tenant improvements, this cycle could be much shorter.

Building typology also plays a key factor in the relative impact of interior fit-outs. For instance, commercial
and residential buildings are renovated at higher
frequencies than other buildings, leading to higher
cumulative impacts of embodied carbon.

In a 2019 study, the Carbon Leadership Forum
measured the impacts of initial construction combined
with mechanical, electrical, and plumbing (MEP) and
tenant improvements (TI), recurring at intervals of 15
years. The results indicated that when replacements
of MEP and TI accumulate over a 60-year building
life span, the combined impacts exceed the initial
construction impacts in certain cases.34
Materials used for interior fit-outs are often made
by companies with highly variable product lines, so
providing EPDs for each product can be time- and
cost-prohibitive.35 In a study conducted by the Carbon
Leadership Forum, the material categories that were
found to carry the highest global warming potential
(GWP) in interior fit-outs, such as aluminum-framed
storefronts, HVAC components, interior partitions, and
wood flooring and underlayment, lacked essential LCA
data.36 These current data limitations are expected to
improve as demand grows for low-embodied-carbon
fit-out materials. Design practitioners should reduce
the quantity of high-embodied-carbon materials if a
low-impact alternative is not available in their region.

Further Opportunities to Reduce
Embodied Carbon in Case Study Buildings
There are several embodied carbon reduction
opportunities that go beyond the specification and
one-for-one material substitution opportunities
included in our analysis. These include:
• Interior finish and fit-out reductions,i including:
• Substituting traditional drywall with lightweight
or alternative (plant-based) drywall materials
• Substituting low-embodied-carbon carpet tiles
made from alternative materials
• Specifying lower-embodied-carbon ceiling tiles
and paint products
• Replacing or redesigning cladding and structural
elements,ii such as:
• Replacing metal decking or light-gauge steel
wall panels with wood-based alternatives
• Redesigning entire structural systems to
leverage lighter-weight materials (such as
wood) and recalculating the size and material
content of slabs and other foundational
structural elements
• Whole-building design considerations,iii including:
• Adaptive reuse of existing buildings
• Reducing floor area for greater occupant
density or more efficient use of floor space
Reducing Embodied Carbon in Buildings www.rmi.org / 28
Discussion
These results lead us to a few powerful observations.

Even though the strategies employed do not include
comprehensive whole-building design strategies,
they still yield a 19%–46% reduction in up-front
embodied carbon through specification and material
substitution measures. Given that these conclusions
are based on three case studies in the Pacific
Northwest, we can note them as strong anecdotal
evidence, rather than broadly applicable conclusions.

We had hoped to draw stronger conclusions from
these case studies about the cost, carbon, and
material impacts of substituting more structural steel
and concrete with wood, but because of the limits of
our study (namely the fact that we were not able to
redesign building structural systems), we were unable
to draw such conclusions.
i Interior finish and fit-out reductions were included to a limited extent in case study 2; they were excluded from the other case studies because interior fit-out and finish materials were not included in the bill of materials for the original projects. ii These changes were not considered in the case studies because they would have required a level of structural redesign beyond the scope of the project.
iii Because this analysis was based on buildings that had already been designed and specified, these changes fell outside the scope of the project.

Key Findings

1. Optimizing the ready-mix concrete design can lead to significant embodied carbon reductions at no cost. Ready-mix concrete design optimization yielded a 14%–33% reduction in project-wide embodied carbon across the three scenarios when compared with the baseline buildings. Depending on the changes to mix design, this measure carries either no cost or a possible cost reduction.

2. Rebar with high recycled content coming from efficient mills, electric arc furnaces, and clean electrical grids can have dramatic impacts at a small cost premium. Rebar contributed up to 10% of total project embodied carbon content in the case study 1 and 2 buildings. For these projects in the Pacific Northwest, the up-front embodied carbon of rebar can be cut in half with minimal impact to the overall project budget, although rebar with high recycled material content may not be available at a low cost premium in other regions.

3. Insulation material selection can drive project-level embodied carbon, but it depends on the baseline material types selected and the quantity of insulation. Case study 2 showed insulation as approximately 20% of the building’s baseline embodied carbon content, leveraging a traditional foam-based insulation board. Rigid and spray foam insulation products utilizing HFO or other low-GWP based foaming agents can reduce embodied carbon impacts significantly. Several emerging products also leverage plant-based materials, which have the potential to store more carbon than is emitted in their production.

4. Glazing remains a critical challenge for reducing embodied carbon, as the process of producing glass requires a significant amount of heat and high-embodied-carbon materials for framing. Products available today can cut embodied carbon in glazing by approximately 25%, but at a 10% cost premium.

5. Finish materials can serve as a key carbon-reduction or carbon-storage opportunity. Case study 2 showed that preoccupancy finish materials (e.g., flooring, carpet tiles, ceiling tiles, and paint) can account for approximately 10% of project-level cradle-to-gate embodied carbon. Some of these elements are capable of >50% reductions at no up-front cost premium, and in some locales, carbon-sequestering materials may even be available.37
3% reduction
Concrete
Optimize concrete mix
14%
33%
14%–33% reduction
None to low-cost premium
See case studies 1, 2, and 3
Rebar
Use high recycled
content rebar
4%
10%
4%–10% reduction
None to low-cost
premium
See case studies 1, 2
Insulation
Select low- or
no-embodied-carbon
insulation products
16%
16% reduction
No cost premium
See case study 2
Finish
Materials
Select low- or
no-embodied-carbon
finish materials (e.g.,
flooring, carpet tiles,
ceiling tiles, paint)
5%
5% reduction
None to low-cost
premium
See case study 2
Glazing
Select
low-embodied-carbon
glazing products
3%
10% cost premium
See case study 2
Reducing Embodied Carbon in Buildings www.rmi.org / 29
The categories in which a project's embodied carbon can be reduced for little to no cost
Exhibit 6
Section 5
Opportunities to Drive Deeper
Savings
Reducing Embodied Carbon in Buildings www.rmi.org / 31
The case studies in Section 4 demonstrate that
the technology and solutions available today can
economically lower the embodied carbon of buildings.

Although not a part of this study, there are several
additional financial levers that could further improve
the economics of low-embodied-carbon buildings:
• Internal carbon pricing: Applying a monetary
cost to carbon via a carbon tax or self-induced
corporate carbon pricing could dramatically
increase the value of low-embodied-carbon
design to the developer. Companies like
Microsoft have implemented an internal cost
of carbon that is used to influence decisions
toward reducing carbon emissions, including
construction carbon emissions.
• Consumer savings: Scaling production of lowembodied-carbon materials could result in cost savings being passed on to the consumer. Savings
from reducing portland cement in a concrete mix,
for instance, may today be realized only by the
ready-mix supplier, but with added transparency
and growing demand for concrete with lower
cement content, these savings may become a
benefit for the purchaser as well.
• Market competition: Increasing the production
of low-embodied-carbon materials is likely
to reduce the cost of the materials. This may
also be accelerated by increased demand from
preferential purchasing policies.
• Developing and reducing embodied carbon
targets: Requiring the measurement of embodied
carbon for new buildings and renovation projects
alone will lead to greater demands for lowembodied-carbon materials and construction techniques. Once embodied carbon is regularly
measured, codes, policies, and standards will
become stronger tools for setting stringent
targets. This will in turn reduce costs as a result
of greater market penetration, familiarity, and
production of critical products.

As the business case for low-embodied-carbon
construction continues to grow and more
practitioners adopt reduction strategies as standard
practice, it is important to acknowledge key factors
that can influence how low-embodied-carbon
opportunities are approached in any given project.

Regional differences and data disparities may
enable certain low-embodied-carbon solutions and
prohibit others. Emerging low-embodied-carbon
materials and techniques can make limiting
embodied carbon simpler, less expensive, or more
impactful as they become available. Finally, lowembodied-carbon building codes and policies are gaining momentum across the United States and will
increase market demand for low-embodied-carbon
materials and construction.

Regional Differences
Regional variations in labor force, material supply
availability, carbon intensity of energy grids, and other factors can significantly alter the economic viability, availability, and workforce capabilities around specific low-embodied-carbon solutions.

Electricity used during manufacturing can come from
regional sources with varying degrees of carbon
intensity. For instance, some steel products made
in factories using electric arc furnaces can be very
low in embodied carbon if the electricity comes
from hydropower or other zero-carbon sources. In
regions using coal and other carbon-intensive fuels
to generate electricity, those same steel products will have much higher embodied carbon.

Opportunities to Drive Deeper
Savings
Reducing Embodied Carbon in Buildings www.rmi.org / 32
The transportation of materials within or across
geographic regions can significantly impact the
embodied carbon of a product. Although the
manufacturing stage typically emits the highest
levels of carbon in the life cycle of a given product,
transportation emissions can be substantial,
particularly when a large quantity of material is
transported across long distances. When evaluating
low-embodied-carbon material options, emissions
associated with transport to the construction site
(lifecycle stage A4) should be considered alongside
the embodied carbon of the given material (lifecycle
stages A1–A3). It is worth noting that many studies,
including this study, do not incorporate lifecycle
stage A4 because the information is not readily
available via tools such as EC3. Additionally, it requires an additional side calculation for each material
depending on its source. In some cases, specifying
local materials that cut down on transportation
emissions will be the better option, whereas in other
cases it will be better to ship materials with low upfront embodied carbon from farther away.

The capability of a local labor force to work with
low-embodied-carbon products varies, affecting a
design and construction team’s ability to implement
certain low-embodied-carbon solutions. Many
products—such as low-embodied-carbon carpet
tiles, thinner wall gypsum boards, and sustainably
sourced sheathing products—look, feel, and are
typically installed like their traditional counterparts.

However, constructing a mass timber structural
system or working with a new cement chemistry may
be a skill set less common to a given region, which
can risk additional time and expense for a project
that specifies these solutions without a trained and
knowledgeable workforce.

The negative impacts of regional differences will
decrease as demand grows for low-embodied-carbon
products, labor forces gain experience with new skill
sets and construction methods, and training becomes
available to work with these materials and solutions.

Source: EC3 Tool
Reducing Embodied Carbon in Buildings www.rmi.org / 33
Regional Data Disparity
Environmental Product Declarations (EPDs) are a key
tool for selecting low-embodied-carbon products.

The availability of EPDs varies by region due to
manufacturers supplying data based on demand from
the local public and private sectors.

The graphs below (Exhibit 13) show the range of
embodied carbon content in ready-mix concrete from
EPDs across California, New York, and Georgia. The
highest value within the colored area indicates that
80% of products represented have less embodied
carbon than the value listed, demonstrating a
conservative target for reduction. A tighter, but still achievable target is demonstrated by the lowest value
within the colored area, indicating that only 20% of
products represented have less embodied carbon
than the value listed. This range is similar across all locales, whereas the extreme minimum and maximum
values vary significantly, indicating that some regions, such as California, have a higher number of EPDs that
show a wider range of products.

California
Min 2
Max 847
Conservative
428
Number of
available EPDs:

Achievable
272
New York
Max 554
Conservative
462
Achievable
240
Min 102
Georgia
21,146 917 473
Achievable
207
Conservative
465
Max 596
Min 54
kg CO2e per yd3 of
ready-mix concrete
Majority
Range
0 200
400
600
800
1,000
Majority
Range
Majority
Range
Embodied carbon range of ready-mix concrete available in California, New York, and Georgia
Exhibit 7
In each location, the "Conservative" value represents that 80% of available EPDs show a lower embodied carbon content per unit of concrete, the "Achievable" value represents that 20% of EPDs show a lower value, and the "Majority Range" captures 60% of available EPDs.

Source: Table S6, Galina Churkina et al., "Buildings as a Global Carbon Sink," Nature Sustainability, 2020 Reducing Embodied Carbon in Buildings www.rmi.org / 34
Advanced Materials to Drive Greater
Change
Emerging low-embodied-carbon materials and
techniques can make limiting embodied carbon
simpler, less expensive, or more impactful as they
become available. Although embodied carbon can be
reduced substantially using widely available products
today, emerging materials and other technologies
may help lower embodied carbon content as they
become available, prove their merit, or come down in
price. Exhibit 8 demonstrates a wide array of building
materials (most of which are readily available today)
that range from high-embodied-carbon materials
to materials with high net embodied carbon storage
potential. Raising awareness around readily available
materials that either reduce or (net) store embodied
carbon alone can dramatically curb building-related
carbon emissions.

The materials outlined in Exhibits 9–11 demonstrate a
variety of embodied carbon reduction measures and
offer alternatives to traditional construction materials with higher embodied carbon. While some materials
are widely available across the United States, others
are emerging and require further testing. It is critical to research the embodied carbon savings offered by
a given material along with specific constructability,
durability, cost, and other factors when choosing
advanced material options.

CO2 Exhibit 8 e emissions and storage capacity of building materials -4.0 -3.5 -3.0 -2.5 -2.0 -1.5 -1.0 -0.5 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 Straw
Dimensioned Lumber
Mass Timber
Laminated Bamboo
Hempcrete
Concrete
Steel (recycled content)
Cement
Gypsum Board
Steel
Polystyrene (EPS)
t CO2e/t material



Exhibit 9 Market-Ready Materials
Reducing Embodied Carbon in Buildings www.rmi.org / 35
Embodied Carbon
Reduction Measure Description Market Readiness
Carbon-negative
carpet backing
By increasing the quantity of pre- and post-recycled
materials, biopolymers, and other bio-based materials,
carpet tile manufacturers can produce products that are carbon negative when measured from cradle to gate.

Products are readily available for
use today.

Plant-based insulation
products
A growing number of plant-based insulation products
are available on the market. These materials are often
considered low in embodied carbon or provide a net
sequestration of carbon in buildings. Cellulose has
been available for decades in the United States but is
being reformulated to work in different form factors.

Hempcrete is another highly sustainable material that
serves as an excellent insulator. Both of these materials are available in the residential market but are not readily available in the in commercial construction market.

Several straw, hempcrete, and
cellulose products are available on
the market today.

Next-gen, low-GWP XPS
insulation products
Low-GWP extruded polystyrene (XPS) insulation
products are made by replacing HFC-134a, a high-GWP
hydrofluorocarbon blowing agent, with a blend of other
blowing agents with lower GWPs. The blends do not
eliminate GWP but offer a lower alternative to traditional XPS products with very high GWP.38
Several products are available in
the United States.

Graphene-infused carbonsequestering paint
Graphene-infused paints are lime-based products with
added graphene for strength and durability. The lime
ingredient absorbs CO2 from the surrounding air as the
paint dries.

Several products are available in
the United States, but their carbon
reduction claims are untested.

Lightweight wallboard
products
Lightweight wallboard products reduce transportation
emissions and are more easily handled on job sites. One example is a lightweight gypsum board that also reduces embodied carbon by requiring less heat and associated
emissions needed to dry the mix. It also uses less water than typical gypsum wallboards.39
Several products are available in
the United States.

Type 1L cement products
The use of limestone as a supplementary cementitious
material (SCM) represents an important, low-cost, highavailability first step toward lowering the embodied emissions of concrete. Limestone is the most readily
available SCM, given that it is already present in
cement and deposits are widely available. The total
emissions abatement potential of limestone is limited
by substitution limits (15% in ASTM), which reflect the reduction in strength associated with use of limestone
as an SCM.

Several products are available in
the United States.

Materials that are readily available but have not yet achieved high market penetration Exhibit 10 Near-Market-Ready Materials
Embodied Carbon
Reduction Measure Description Market Readiness
Alternative
cement
chemistries and
processes
Several emerging cement chemistries and production methods are being pursued, requiring less fuel for cement production and resulting in fewer chemical reaction emissions.

Some of these technologies are currently in use in a limited number of production facilities for ready-mix concrete, others are currently being used only to make precast pavers, and others are earlier in development.

Market readiness varies based on
the technology and the producer.

Most products have undergone
testing and are currently being
offered by one or more ready-mix
concrete suppliers.

Higher
concentrations of
SCMs in concrete
Substituting cement with supplementary cementitious materials (SCMs), such as fly ash, slag, or pozzolanic materials, in higher percentages can drive greater carbon reductions. SCMs from nonfossil fuel sources such as glass pozzolan or rice husks can further enhance carbon reductions. This substitution leads to lower cement requirements in the concrete mix but is dependent on the supply of SCMs, availability of high SCM mix design performance data, and architectural/structural design requirements. Higher concentrations of SCMs than are typically accepted by industry today can increase the time to reach specified compressive strengths, which is why this strategy is typically limited or not used at all for quick vertical construction projects with short timelines.

Producers are consistently looking
for ways to reduce cement content
in concrete mix by increasing the
amount of SCMs, but high (50%-
plus) SCM mixes are not currently
market validated in most regions.

CO2-injected
cement products
These products claim to reduce embodied carbon by directly injecting carbon dioxide into concrete, where it is mineralized and permanently embedded. Since cement naturally carbonates over time, it remains unclear whether this process offers long-term carbon advantages, particularly given the need for high-grade CO2. Some companies are also looking at capturing CO2 from cement kilns.

These products are available in
certain locales, but their embodied
carbon reduction claims are
untested.

Plant-based wall
panels
SIPs and other exterior panels can be made with plant-based materials.

Some carbon accounting systems may consider these materials to be net carbon sequestering, and others would consider them to be low embodied carbon when compared with the petroleum- or gypsumbased traditional materials that they replace.

Straw bale SIPs and prefabricated
straw bale wall panels have
been successfully implemented
in the residential market for
selective projects; however, these
applications are not yet common in
the commercial market.

CO2-sequestered
aggregates for
concrete
This new technology uses CO2 as a raw material for making carbonate rocks. The carbonate rocks produced are used in place of natural limestone rock mined from quarries, which is the principal component of concrete.

Several startups are actively
developing this new technology.

Magnesium oxide
wallboard
Magnesium oxide wallboards can be used in place of traditional gypsum drywall or other sheathing applications. The calcination process required to manufacture this product occurs at lower temperatures compared with that of traditional portland cement or calcium oxide, resulting in reduced manufacturing emissions.

Several US manufacturers
offer products with a variety of
applications and uses, but some
studies have highlighted negative
moisture-absorbing features that
can lead to mold and moisture
damage in certain cases.40
Laminated
bamboo lumber
and structural
bamboo
Bamboo lumber products are a viable alternative to lumber. Bamboo offers some advantageous strength characteristics compared to typical lumber products, but there are outstanding questions about the longevity and general resilience of bamboo lumber products.41 Not tested or produced at scale in
the United States
Reducing Embodied Carbon in Buildings www.rmi.org / 36
Materials that are available on a small- or pilot-project scale but are not yet broadly available on the market Exhibit 11 Materials in Development
Embodied Carbon
Reduction Measure Description Market Readiness
Zero-carbon steel
Using molten oxide electrolysis or renewably
produced hydrogen to produce steel and reducing
the amount of virgin steel through reuse or
recycling can enable a zero-carbon steel product.

Currently, lower-embodied-carbon steels are
available, but there is not a market-ready zerocarbon steel.42 This product is not yet available on the market,
but many producers are improving the embodied
carbon of available steel year-over-year, and there
are active efforts to produce zero-carbon steel in
the United States and Europe.

Glass pozzolan SCMs
SCMs can be made from recycled glass products,
which proponents claim improves performance of
the ultimate concrete mix.

There are several emerging companies working in
conjunction with local recycling centers to bring
glass pozzolan SCMs to market. The greatest limits
are due to economics and availability of the SCMs.

Cement production
powered by alternative
fuels
Using alternative fuels for the heating process
during the production of clinker for ordinary
portland cement would address approximately
40% of the current up-front embodied carbon of
cement production. This is technically achievable
but has not been tested at a large scale. The
process would not address the emissions related
to chemical processes.

This is still in the early stages of development.

Self-healing and living
materials
Self-healing materials, including concrete, can
reduce embodied carbon by increasing the
longevity of certain materials with lives that
are limited by material failure. Some living
materials can further reduce embodied carbon
by sequestering carbon dioxide from the
atmosphere in the process of forming.43
Most self-healing and/or living materials are in
early stages of laboratory development.

Materials that are under development and that could provide significant embodied carbon reductions for critical building materials
Reducing Embodied Carbon in Buildings www.rmi.org / 37
Reducing Embodied Carbon in Buildings www.rmi.org / 38
Codes and Policy
A growing number of codes and policies are targeting
embodied carbon reductions across city, state, and
federal levels. Codes, standards, regulations, and
incentive programs can all be effective tools for
driving change by promoting and establishing best
practices to reduce embodied carbon in construction.

Already we have seen several low-embodied-carbon
policies put into effect, including the Buy Clean
California Act. The policy drives low-embodiedcarbon procurement by requiring contractors bidding on state infrastructure and construction
projects to disclose the Environmental Product
Declarations (EPDs) of certain materials and
mandates a preference for lower-carbon products.

Buy Clean California has inspired several other state
legislatures to pursue similar policies.

Further, in 2021 the US General Services
Administration approved an advice letter
recommending two key strategies to limit embodied
carbon in the federal government:44

1. The first strategy, a material approach, applies
to all projects. This approach requires EPDs for
75% of materials used in a project and requires
that their emissions rank in the best-performing
80% in terms of global warming potential among
functionally equivalent products.

2. The second strategy is a whole-building life
cycle assessment (WBLCA) approach, applicable
to larger projects over $3.095 million. The
WBLCA approach requires that the life cycle
assessment of a building’s design shows at
least a 20% carbon reduction, as compared
with a baseline building.

These policies aim to reduce demand for highembodied-carbon products through preferential purchasing of low-impact materials. The Athena
Sustainable Materials Institute highlights a number
of other approaches to limiting embodied carbon
through codes and policies,45 including:
• Other financial incentives, such as bid incentives
or tax credits
• Transparency initiatives such as requiring or
incentivizing the measurement and disclosure of
embodied carbon data for building projects
• Performance approaches such as requiring or
incentivizing the reduction of embodied carbon
for building projects relative to:
• A customized performance target defined by a
benchmarking system
• A fixed performance target related to the GWP
of a building or material
• Prescriptive approaches such as requiring or
incentivizing the use of specific materials or
design measures
While these code and policy solutions have shown
to be effective in select contexts, this is not an
exhaustive list. A report by the Carbon Neutral
Cities Alliance, City Policy Framework for Dramatically Reducing Embodied Carbon, demonstrates the
wide-ranging scope of embodied carbon reduction
policies by outlining 52 policies spanning five
categories: zoning and land use, building regulations,
procurement, waste and circularity, and financial
policies.46 New proposals for these types of
legislation, as well as governmental commitments
such as C40 Cities’ Clean Construction Declaration,
are gaining momentum across the United States.

In addition to governmental policies, corporations
are issuing policies on a monthly basis that limit
embodied carbon.

Section 6
Conclusion
Reducing Embodied Carbon in Buildings www.rmi.org / 40
Reducing embodied carbon is an urgent and
critical issue, because the trajectory of embodied
carbon emissions is not currently aligned with global
climate targets. Since 2010, as global emissions
from building operations have decreased slightly,
construction-related emissions have actually increased
by 1.5%.47 It is imperative that practitioners employ
the strategies and solutions available today to
accelerate the adoption of low-embodied-carbon
construction. These changes are necessary to deliver
the unprecedented action required to meet the goal of
the Paris Climate Agreement and limit global warming
to 1.5°C.

This report demonstrates that midsized
commercial building projects can reduce embodied
carbon by up to 46% at less than a 1% cost premium
using materials that are widely available today. The
reductions highlighted by our three case studies are
backed up by methods and materials that are widely
available and simple to implement. Reductions can
go well beyond 50% by considering whole-building
design strategies, incurring a higher cost premium,
or leveraging some of the advanced materials that
are coming down the R&D pipeline. The technologies
that enable low-embodied-carbon construction will
continue to evolve, and regional nuances will continue
to influence the efficacy of individual products or
solutions. But the design methods and high-level
considerations highlighted in this report can
be applied to any project today, offering lasting
solutions to eliminate and sequester carbon
emissions in our buildings.

Conclusion
Appendix
Additional Case Studies
Construction
Type Study Name Location
Building
Typology Size (ft2) Link
Mid-rise steel and
concrete
Tally case study Seattle, WA Residence halls at
the University of
Washington
size not listed https://choosetally.
com/casestudy/
Mid-rise steel and
concrete
Case study 1 from
“Mass Timber
Optimization and
LCA,” Carbon
Leadership Forum
(CLF)
WA 9-story commercial
building
size not listed https://
carbonleadershipforum.
org/mass-timberoptimization-and-lca/
Concrete tilt-up
Panelized
Roof Systems,
Woodworks
CA, WA, OR, HI Commercial
buildings
various https://www.
woodworks.org/wpcontent/uploads/ISPanelized-Roofs.pdf Mid-rise mass
timber (CLT)
LCA of Katerra’s
CLT and Catalyst
Building, CLF
Spokane, WA 5-story office
building
168,800 https://
carbonleadershipforum.
org/katerra/
Mid-rise mass
timber (CLT and
glulam)
Comparative LifeCycle Assessment
of a Mass Timber
Building and
Concrete Alternative
Portland, OR 12-story mixed-use
apartment/office
building
89,986 https://www.fpl.
fs.fed.us/documnts/
pdf2020/fpl_2020_
liang001.pdf
Mid-rise wood
frame
Luxury WoodFrame Apartment
Community
Completes Dense,
Mixed-Use Urban
Development,
Woodworks
Atlanta, GA 5-story, wood-frame
apartment buildings
(3 buildings)
275,000 https://www.
woodworks.org/wpcontent/uploads/
CrescentTerminus_
CaseStudy.pdf
Reducing Embodied Carbon in Buildings www.rmi.org / 42
The case studies below were compiled while conducting research for this report and are included here for additional insight into the impacts of various approaches to lowering the embodied carbon content of low- and mid-rise buildings.

APPENDIX: Additional Case Studies
Exhibit A1 Additional Case Studies
Endnotes
Reducing Embodied Carbon in Buildings www.rmi.org / 44

1. Bringing Embodied Carbon Upfront: Coordinated
Action for the Building and Construction Sector to
Tackle Embodied Carbon, World Green Building
Council, 2019, https://www.worldgbc.org/sites/
default/files/WorldGBC_Bringing_Embodied_
Carbon_Upfront.pdf; and Robert James Pratt,
“A Common Ask: Collecting ESG Data on Building
Materials, Starting with Embodied Carbon,” Urban
Land, January 31, 2021, https://urbanland.uli.
org/sustainability/a-common-ask-collectingesg-data-on-building-materials-starting-withembodied-carbon/.

2. Kathrina Simonen, Barbara X. Rodriguez, and
Catherine De Wolf, “Benchmarking the Embodied
Carbon of Buildings,” Technology | Architecture +
Design 1, no. 2 (2017): 208–218, https://doi.org/10.1
080/24751448.2017.1354623.

3. Sustainability of Construction Works—Assessment of
Buildings, Part 2: Framework for the Assessment of
Environmental Performance, European Committee
for Standardization, 2011.

4. “New Buildings: Embodied Carbon,” Architecture
2030, accessed April 1, 2021, https://
architecture2030.org/new-buildings-embodied/.

5. Lizhen Huang et al., “Carbon Emission of Global
Construction Sector,” Renewable and Sustainable
Energy Reviews 81 (January 2018): 1906–1916,
https://doi.org/10.1016/j.rser.2017.06.001.

6. Bringing Embodied Carbon Upfront, World Green
Building Council, 2019.

7. The Critical Role of Buildings, IEA, 2019, https://
www.iea.org/reports/the-critical-role-ofbuildings#highlights.

8. Embodied Carbon in Building Materials for Real Estate, Urban Land Institute, 2019, https://americas.
uli.org/wp-content/uploads/ULI-Documents/
Greenprint-Embodied-Carbon-Report_FINAL.
pdf.

9. Centering Equity in the Sustainable Building
Sector: Comprehensive Summary: CESBS Launch
Summit NAACP, 2018, https://naacp.org/wpcontent/uploads/2020/04/CESBS-SummitComprehensive-Summary_July-2019.pdf.

10. Paula Melton, “The Urgency of Embodied Carbon
and What You Can Do about It,” BuildingGreen,
September 10, 2018, https://www.buildinggreen.
com/feature/urgency-embodied-carbon-andwhat-you-can-do-about-it.

11. Colin R. Gagg, “Cement and Concrete as an
Engineering Material: An Historic Appraisal
and Case Study Analysis,” Engineering Failure
Analysis 40 (May 1, 2014): 114–140, https://doi.
org/10.1016/j.engfailanal.2014.02.004.

12. Inventory of U.S. Greenhouse Gas Emissions and
Sinks: 1990–2018, US Environmental Protection
Agency, 2020, https://www.epa.gov/sites/
production/files/2020-04/documents/us-ghginventory-2020-main-text.pdf; and “Manufacturing Energy and Carbon Footprint,” US Department of
Energy, https://www.energy.gov/sites/prod/
files/2018/10/f56/2014_mecs_cement_energy_
footprint.pdf.

13. Gagg, “Cement and Concrete as an Engineering
Material,” 2014; and Inventory of U.S. Greenhouse
Gas Emissions and Sinks, US Environmental
Protection Agency, 2020.

14. “Supplementary Cementitious Material:

An Overview,” ScienceDirect, https://www.
sciencedirect.com/topics/engineering/
supplementary-cementitious-material.

15. Embodied Carbon: A Clearer View of Carbon
Emissions, Walter P. Moore, 2020, https://www.
walterpmoore.com/sites/default/files/wpm_
embodied_carbon_report_2020.pdf.

Endnotes
Reducing Embodied Carbon in Buildings www.rmi.org / 45

16. “Supplementary Cementitious Material,”
ScienceDirect.

17. Thomas Czigler et al., “Laying the Foundation for
Zero-Carbon Cement,” McKinsey & Company,
May 14, 2020, https://www.mckinsey.com/
industries/chemicals/our-insights/laying-thefoundation-for-zero-carbon-cement.

18. 2019 U.S. Cement Industry Annual Yearbook,
Portland Cement Association, 2019, https://www.
cement.org/morereports/2018-us-cementindustry-annual-yearbook.

19. Inventory of U.S. Greenhouse Gas Emissions and
Sinks, US Environmental Protection Agency, 2020.

20. “Manufacturing Energy and Carbon Footprint,” US
Department of Energy; and ibid.

21. Ali Hasanbeigi and Cecilia Springer, How Clean Is
the U.S. Steel Industry? Global Efficiency
Intelligence, 2019,
https://www.globalefficiencyintel.com/ussteel-industry-benchmarking-energy-co2- intensities.

22. Profile of the American Iron and Steel Institute,
American Iron and Steel Institute, 2019, https://
www.steel.org/industry-data/reports/;
Inventory of U.S. Greenhouse Gas Emissions and
Sinks, US Environmental Protection Agency,
2020; and “Manufacturing Energy and Carbon
Footprint,” US Department of Energy.

23. Jeffrey Tomich, “U.S. Readies First Wind-Powered
Steel Plant,” E&E News, November 15, 2019,
https://www.eenews.net/stories/1061552453.

24. “ENERGY STAR Focus on Energy Efficiency in Iron
and Steel Manufacturing,” Energy Star, https://
www.energystar.gov/industrial_plants/
measure-track-and-benchmark/energy-starenergy-5.

25. Structural Steel: An Industry Overview, American
Institute of Steel Construction, August 2018,
https://www.aisc.org/globalassets/aisc/
publications/white-papers/structural_steel_
industry_overview_2018.pdf.

26. “Forest Management Certification,” Forest
Stewardship Council, https://fsc.org/en/forestmanagement-certification.

27. James L. Howard and Shaobo Liang, “United
States Forest Products Annual Market Review
and Prospects, 2015–2019,” US Department of
Agriculture, https://unece.org/fileadmin/DAM/
timber/country-info/statements/usa2018.pdf.

28. “About – Carbon Smart Materials Palette,”
Architecture 2030, accessed March 30, 2021,
https://materialspalette.org/about/.

29. The Greenest Building: Quantifying the
Environmental Value of Building Reuse, National
Trust for Historic Preservation, 2011, https://
forum.savingplaces.org/HigherLogic/
System/DownloadDocumentFile.
ashx?DocumentFileKey=5119e24d-ae4c-3402-
7c8e-38a11a4fca12&forceDialog=0.

30. Larry Strain, “10 Steps to Reducing Embodied
Carbon,” AIA, https://www.aia.org/
articles/70446-ten-steps-to-reducingembodied-carbon.

31. Data from 2018 Commercial Buildings Energy
Consumption Survey, US Energy Information
Administration, 2020, https://www.eia.gov/
consumption/commercial/data/2018/index.
php.

32. Estimates of Embodied Carbon for Mechanical,
Electrical, Plumbing and Tenant Improvements:

Summary Document, Carbon Leadership Forum,
April 2019, https://carbonleadershipforum.
org/lca-of-mep-systems-and-tenantimprovements/.

Reducing Embodied Carbon in Buildings www.rmi.org / 46

33. Designing for the Future: Interior Life Cycle Analysis, Hawley Peterson Snyder, February 7, 2020,
https://www.oneworkplace.com/assets/files/
HPS-ONEder-Grant.pdf.

34. Estimates of Embodied Carbon for Mechanical,
Electrical, Plumbing and Tenant Improvements:

Summary Document, Carbon Leadership Forum,
April 2019.

35. Designing for the Future, Hawley Peterson Snyder,
2020.

36. Life Cycle Assessment of a Commercial Tenant
Improvement Project: Summary Document, WeWork
and Carbon Leadership Forum, October 2019,
https://carbonleadershipforum.org/lca-of-awework-tenant-improvement-project/.

37. “Carbon Storing Carpet. It’s a Thing,” Interface,
accessed March 17, 2021, https://www.interface.
com/US/en-US/sustainability/climate-takeback/carbon-storing-carpet-en_US.

38. “Transitioning to Low-GWP Alternatives in
Building/Construction Foams,” US Environmental
Protection Agency, 2011, https://www.epa.gov/
sites/production/files/2015-07/documents/
transitioning_to_low-gwp_alternatives_in_
building_and_construction_foams.pdf.

39. “Gypsum Board – Carbon Smart Materials Palette,”
Architecture 2030, accessed March 30, 2021,
https://materialspalette.org/gypsum-board/.

40. Marina Gravit et al., “Problems of Magnesium
Oxide Wallboard Usage in Construction,” IOP
Conference Series: Earth and Environmental Science
90 (2017): 012103, https://iopscience.iop.org/
article/10.1088/1755-1315/90/1/012103/pdf.

41. Lilly Cao, “How Effective is Laminated Bamboo
for Structural Applications?” ArchDaily, February
29, 2020, https://www.archdaily.com/934274/
how-effective-is-bamboo-for-structuralapplications.

42. “MOE Technology,” Boston Metal, accessed March
30, 2021, https://www.bostonmetal.com/
moe-technology/; and Frédéric Simon, “Swedish
Steel Boss: ‘Our Pilot Plant Will Only Emit Water
Vapour,’” EURACTIV, May 10, 2018, https://www.
euractiv.com/section/energy/interview/hybritceo-our-pilot-steel-plant-will-only-emit-watervapour/.

43. Amos Zeeberg, “Bricks Alive! Scientists Create
Living Concrete,” New York Times, January 15,
2020, https://www.nytimes.com/2020/01/15/
science/construction-concrete-bacteriaphotosynthesis.html.

44. “GSA Green Building Advisory Committee Advice
Letter: Policy Recommendations for Procurement
of Low Embodied Energy and Carbon Materials
by Federal Agencies,” US General Services
Administration, February 17, 2021, https://www.
gsa.gov/governmentwide-initiatives/federalhighperformance-buildings/policy/greenbuilding-advisory-committee/advice-lettersand-resolutions.

45. Jennifer O’Connor and Matt Bowick, “Reducing
Embodied Environmental Impacts of Buildings:

Policy Options and Technical Infrastructure,”
Athena Sustainable Materials Institute, December
2019, http://www.athenasmi.org/wp-content/
uploads/2019/12/Policy_white_paper_
December_2019.pdf.

46. City Policy Framework for Dramatically Reducing
Embodied Carbon: 52 Detailed Policies to Reduce
Embodied Carbon, Carbon Neutral Cities Alliance,
One Click LCA, and Architecture 2030, 2019,
https://www.embodiedcarbonpolicies.com.

47. “Delivering the Paris Agreement: The Role of the
Built Environment,” World Green Building Council,
https://www.worldgbc.org/sites/default/
files/2050%20Letter%20Final.pdf.

Matt Jungclaus, Rebecca Esau, Victor Olgyay, and Audrey Rempher, Reducing Embodied Carbon in Buildings: Low-Cost, High-Value Opportunities, RMI, 2021, http://www.rmi.org/insight/reducing-embodied-carbon-in-buildings.

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