2023 CLF North American Material Baselines Report

Developed by the Carbon Leadership Forum (CLF), this report provides an overview of the state of building product EPDs in North America. The CLF baselines are industry-wide GWP estimates for all building products manufactured in North America, most of which are based off of IW-EPDs, if available. The appendix includes a list of all the domestic EPDs available for each product category, and a summary of embodied carbon impacts.

AIA-CLF Embodied Carbon Toolkit for Architects

Written by the Carbon Leadership Forum, this extensive three-part toolkit provides architects and other interested stakeholders with an introduction to embodied carbon, how to measure embodied carbon, and strategies to reduce it.

Hines Embodied Carbon Reduction Guide

This guide was developed by Hines and Magnusson Klemencic Associates (MKA) to provide an overview of embodied carbon for building designers, contractors, and other building professionals. The guide describes how to measure the embodied carbon of materials and how to conduct a whole building life cycle assessment (WBLCA), as well as what strategies to use to reduce embodied carbon in various building systems.

Mythbusting Mass Timber

This report debunks four common myths about using wood in construction: that mass timber buildings are carbon neutral, that wood is always more sustainable than concrete, that mass timber buildings absorb carbon emissions, and that all wood is good wood. The report is written by architecture firms LEVER and Atelier Ten.

Roadmap to Reaching Zero Embodied Carbon in Federal Building Projects

This report is published by RMI, and it provides a pathway for federal projects to achieve zero embodied carbon by 2050. The main strategies discussed in the report are passing a robust Buy Clean procurement program, requiring and/or incentivizing low-embodied carbon materials, incorporating whole-project embodied carbon performance standards, and creating a portfolio planning framework that incorporates the value of reducing embodied carbon.

The Hidden Climate Impact of Residential Construction

Written by RMI, this report describes the significant embodied carbon impact from low-rise residential construction in the US, and what can be done to mitigate it. The report provides the steps needed for builders and designers to achieve 30 to 50 percent reductions in embodied carbon at cost parity and with readily available materials.

Transformative Carbon-Storing Materials: Accelerating an Ecosystem

The Carbon Leadership Forum examines six carbon-storing materials for their potential to be scaled and adopted in future markets and building material supply chains with a focus on data center construction. This report also presents a methodology for evaluating a new material's impact in the carbon-positive buildings space.

Carbon-Storing Materials

The Carbon Leadership Forum investigates the technical, economic, and social considerations of low-carbon materials in this Microsoft-funded summary report. The authors identified three time horizons for implementation of low-carbon materials ranging from 20% reduction strategies available immediately to 100% reduction strategies available in the next 5 years.

Embodied Carbon Building Code Overlay

This document provides amendments to the International Building Code in the form of side-by-side edits to existing code language. The overlay encourages policymakers to focus on optimizing carbon savings in materials, leveraging EPDs to set benchmarks for products.

Low Carbon Concrete in Residential Construction

This Portland-based pilot project is part of an ongoing effort to better understand the behavior of low-carbon concrete in light of the city's recently passed concrete carbon limits. In this case study, several concrete mixes were tested in a residential setting and analyzed with respect to technical performance, workability, and cost.

City of Vancouver LCA Embodied Carbon Guidelines

The City of Vancouver offers technical assistance on modeling embodied carbon to prove compliance with the city's embodied requirements outlined in Section 10.4 of the VBBL passed in May 2022. This document can be referenced in other policies or programs to encourage the measuring or reducing of carbon, such as re-zoning policies.

Embodied Carbon Reduction Roadmap

Arup outlines several pathways for reducing embodied carbon in buildings and proposes policy strategies for implementation. California was chosen as a case study for this research because of its history of progressive climate targets and policy actions.

Advancing the LCA Ecosystem

The Carbon Leadership Forum describes their vision for an ideal LCA ecosystem—the network of data, tools, standards, and organizations that contribute to the creation of LCAs for products and projects—in the context of both policy and private sector action around decarbonization.

Whole Life Carbon Assessment for the Built Environment

This UK-based standard presents a methodology for assessing whole life carbon (WLC) in buildings, which includes operational carbon, embodied carbon, and user carbon. WLC assessors must meet the requirements outlined in the report for the WLCA to be considered compliant with the standard.

Addressing Embodied Carbon in Building Codes

This factsheet shows how the building code can address embodied carbon from buildings as we aim to reduce national GHG emissions 50% by 2030. Building codes have been one of the most influential tools to address climate change: The energy code addresses operational emissions, and the building code address resiliency. The document illustrates cost considerations and the market’s readiness to address both prescriptive and performance-based embodied carbon requirements. Jurisdictions can use existing policies, processes, and fee structures to present, confirm, and enforce these requirements.

Sector Supplement for Measuring and Accounting for Embodied Emissions in the Built Environment

Compiled by Brightworks Sustainability and WAP Sustainability, this Sector Supplement seeks to propel accounting for embodied emissions in corporate Greenhouse Gas (GHG) accounting efforts by providing clarity on how to measure, account and report for embodied emissions as Scope 3 emissions under the GHG Protocol Scope 3 Standard.

Lifecycle GHG Impacts in Codes

NBI’s report presents language to incorporate embodied carbon requirements in building codes. Researchers explain the need to address the embodied carbon of the highest emitting materials and the carbon emission benefits for jurisdictions. This report works to address the current lack of understanding of what a regulation on embodied carbon would look like in a U.S. base code. The code acknowledges the importance of building materials in the construction industry and aims to achieve practical reductions in climate impact by selecting lower embodied carbon materials. Example code language can be adopted by jurisdictions starting with EPD reporting to target GWP limits for specific materials, and finally moving to whole building lifecycle analysis.

Achieving Real Net-Zero Emission Homes: Embodied carbon scenario analysis of the upper tiers of performance in the 2020 Canadian National Building Code

This report investigates the relative impacts of operational carbon emissions and material carbon emissions in low rise Canadian homes. Three housing archetypes were provided by Natural Resources Canada (NRCan), along with HOT2000 energy modeling data for these all-electric homes.

Refrigerants & Environmental Impacts, A Best Practices Guide

Refrigerants' operational carbon is an essential consideration in carbon neutral buildings. Integral Group's guide can support teams make well-informed decisions in the design of refrigerant-based systems. Early consideration of refrigerants can impact ta building's emissions for years to come. The guide reviews currently available refrigerants for common system types, with advice on how to reduce refrigerant charge, leakage, and enhance recovery at end of life. It should be considered ‘live’ and will be updated periodically to reflect the latest industry data.

Decarbonizing construction: Guidance for investors and developers to reduce embodied carbon

The WBCSD and One Click LCA report provides a resource to companies who want to set requirements for embodied carbon reductions in projects they finance and develop in a performance-based way. It also references a selection of emerging national regulations focusing on embodied carbon. And it provides examples of how to include circular solutions in the design phase of projects, which is an important economic, environmental and social opportunity to catalyze innovation and new business models to reduce embodied carbon. We encourage investors, developers, asset managers, lenders and tenants to use this resource to set requirements for carbon performance and pursue sustainability strategies in the earliest phases of project planning and development.

Reducing Embodied Carbon Isn’t all About Materials

Make Architects explores the case for building reuse and how designers can design for future reuse. Topics address the building form, structure, façade, and material section. The document includes case studies and compelling graphics.

Framework for Design Excellence: Design for Resources

AIA's Framework for Design Excellence represents the defining principles of good design in the 21st century. Comprised of 10 principles and accompanied by searching questions, the Framework seeks to inform progress toward a zero-carbon, equitable, resilient, and healthy built environment. The Design for Resources section is focused on material selection, health, embodied carbon, and waste diversion.

Building the Case for Net Zero UK GBC

This UK Green Building Council report presents the findings of a feasibility study that shines a light on the real-world implications for achieving new net zero buildings. It illustrates how new buildings can be designed to reach net zero performance targets and the effect this has on cost. The findings are intended to improve the collective understanding for the buildings sector and help build the case for new net zero buildings.

Embodied Carbon in Building Materials for Real Estate

ULI's report prepares the real estate market for a low-carbon materials future, makes the business case for why real estate should pay attention, highlights smart steps to reduce embodied carbon, and showcases peers already addressing the issue.

Bringing Embodied Carbon Upfront: Coordinated Action for the Building and Construction Sector to Tackle Embodied Carbon

WBCSD's report emphasizes that it's critical to create a conversation around the value and importance of embodied carbon, with the aim of creating and stimulating market demand for transparency, improvements, and verification of embodied carbon reductions. To be successful, the industry needs radical cross-sector coordination to revolutionize the buildings and construction sector towards a net zero future, and tackle embodied carbon emissions.

2021 Material Baseline Report

CLF's material baselines provides information about the high, median, and low embodied carbon impacts of a material category. Designers and policy makers alike can use the baseline numbers as a starting point from which to develop carbon caps or reductions.

Concrete Solutions Guide

RMI's Concrete Solutions Guide provides a user-friendly overview of proven and scalable solutions to reduce concrete’s contribution to climate change. This guide highlights six key opportunities to reduce embodied carbon in concrete products without compromising financial or material performance. Based on decades of research, the solutions are market-ready and based on real-world trials. In addition to helping advance the environmental goals of concrete purchasers, these solutions offer opportunities for producers to reduce costs and establish a leadership role in a changing industry.

Reducing Embodied Carbon in Buildings

RMI's report highlights low-cost and no-cost solutions for reducing upfront embodied carbon in buildings during a project’s design and construction phases. In case studies of three common building types, applying these solutions demonstrates an embodied carbon savings potential of 24 - 46% at cost premiums of less than 1%.

Net-zero Buildings Where do we Stand?

This report from WBCSD and Arup details the results of six whole life cycle assessment (WLCA) case studies to illustrate some of the challenges, barriers, and opportunities relating to the building industry’s carbon footprint. The case studies are presented in easily digestible graphics that present the upfront and whole life embodied carbon emissions. The report aims to provide an insight into the industry’s current performance and compare it to possible net-zero trajectories.

Clean Construction Policy Explorer

C40's Clean Construction Policy Explorer is an interactive dashboard showing how cities around the world are supporting the transition towards a resource-efficient and low- to zero-emissions construction sector. Use the map to explore and learn about the actions cities are taking to tackle the embodied emissions of their built environment. The map is frequently updated.

EPD Requirement in Procurement Policies

Carbon Leadership Forum's analysis of environmental product declaration (EPD) definitions in Buy Clean and other North American procurement policies. The document presents when to use EPDs within policy development and when EPDs are not a helpful tool and how they can be improved.

CLF Policy Toolkit

Carbon Leadership Forum's Carbon Policy Toolkit provides a variety of educational resources to support those who are drafting policies on reducing embodied carbon. The website also includes a frequently updated policy map and additional policy resources.

City Policy Framework for Dramatically Reducing Embodied Carbon

Developed by the Carbon Neutral Cities Alliance, Bionova Ltd, and Architecture 2030, this policy framework is for cities and other government bodies to develop a strategy, action plan and policies they can adopt to reduce the embodied carbon in transportation, transport, use and end of life of construction materials.

Embodied Carbon of Buildings and Infrastructure – International Policy Review

The Forestry Innovation's report is of interest for any jurisdiction that has responsibility for the development and construction of buildings and/or for sustainability and climate change issues. The report provides a review of global best practices and the assessment of the current domestic policy environment could provide insights into the development of an embodied carbon initiative.

Embodied Carbon in Construction Policy Primer for Ontario

This policy primer is intended for design teams and policymakers interested in addressing embodied carbon, emissions associated with construction material extraction, manufacture, and transportation, and building and infrastructure construction, maintenance, and decommissioning in the Ontario context. The primer provides an overview of the concept of embodied carbon and describes how life cycle assessment (LCA) can be used to calculate and minimize life cycle GHG impacts from construction projects.

Bay Area Low-Carbon Concrete Codes Project

The County of Marin developed standards around practical requirements for the composition of concrete that maintains adequate strength and durability for the intended application and at the same time reduces greenhouse gas emissions associated with concrete composition. This code includes pathways for compliance with either reduced cement levels or lower-emission supplementary cementitious materials.

CAL Green: California Green Buildings Standards Code

CAL Green is the first-in-the-nation mandatory green building standards code. Section 5.409 of the 2017 Intervening Code Supplements details a pathway to compliance through Life Cycle Analysis. In 2007, the California Buildings Standards Commission developed green building standards in an effort to meet the goals of California’s landmark initiative AB 32, which established a comprehensive program of cost-effective reductions of greenhouse gases (GHG) to 1990 levels by 2020.

Buy Clean California Act

The Buy Clean California Act, AB262, states the Department of General Services (DGS) is required to establish and publish the maximum acceptable Global Warming Potential (GWP). It targets embedded carbon emissions of structural steel (hot-rolled sections, hollow structural sections, and plate), carbon steel rebar, flat glass, and mineral wool board insulation. These materials must have a GWP that does not exceed the limit set by DGS.

Tool for Reduction and Assessment of Chemicals and Other Environmental Impacts (TRACI)

TRACI is an environmental impact assessment tool created by the US Environmental Protection Agency. The tool provides characterization factors for Life Cycle Impact Assessment (LCIA), industrial ecology, and sustainability metrics.

Embodied Carbon in Construction (EC3 LCA Tool)

This open source tool to help construction professionals efficiently quantify, report, and reduce embodied carbon. Through BuildingTransparency.org professionals can find and compare materials, plan and compare buildings, declare products, and verify and audit EPDs for incorporation into full LCA.

Life Cycle Assessment of Buildings: Technical Guidance

The Carbon Leadership Forum's Technical Guidance provides detailed recommendations for conducting life cycle assessments of buildings and is directed towards seasoned LCA practitioners and LCA tool developers in North America.

Life Cycle Assessment of Buildings: A Practice Guide

The Carbon Leadership Forum published this guide to introduce the concept of life cycle assessment to building professionals. The Practice Guide is divided into two parts: 1. an introduction that addresses how buildings impact the environment and how LCA can be used to quantify environmental impact and 2. an implementation section that describes the five key steps to conducting an LCA of a building.

Critical Issues When Comparing Whole Building & Building Product Environmental Performance

MIT Concrete Sustainability Hub's paper aims to address critical issues and make recommendations to practitioners and those developing guidance to enable more robust comparisons of building products and whole buildings. The paper classifies critical issues when comparing building and building product environmental performance into two categories: system boundaries and analytical approach. The paper recognizes the desire to perform comparisons today that cannot be put off until methodologies advance further and offers two kinds of recommendations: current practice and future advances.

Enhancing the Value of Life Cycle Assessment

Deloitt's paper outlines how LCA can be used to assess the end-to-end environmental impacts of a business decision on overall value creation. The paper evaluates several value-creating business objectives, and shows how the LCA methodology can help companies achieve these goals.

USDA Mass Timber Material Quantities Final Report

This study explores how mass timber buildings can be optimized for material efficiency and support a regionally-specific life cycle assessment case study of a mass timber office building in the Pacific Northwest. The University of Washington Architecture team defined a reference commercial office building using heavy timber/cross-laminated timber (CLT) to substitute for conventional construction. The School of Forest Resources Team developed regionally-specific LCA models to evaluate the environmental impact of potential CLT production in the Olympic Peninsula.

Life Cycle Assessment of Residential Buildings: A Case Study in Canada

The World Academy of Science, Engineering and Technology published this Life Cycle Assessment in the International Journal of Energy and Environmental Engineering. LCA methodology was employed to study the primary energy uses and associated environmental impacts of different phases (i.e. product, construction, use, end of life, and beyond building life) for residential buildings. Four different alternatives of residential buildings in Vancouver (BC, Canada) with a 50-year lifespan have been evaluated, including High Rise Apartment (HRA), Low Rise Apartment (LRA), Single family Attached House (SAH), and Single family Detached House (SDH). Life cycle performance of the buildings is evaluated for embodied energy, embodied environmental impacts, operational energy, operational environmental impacts, total life cycle energy, and total life cycle environmental impacts.

A Life Cycle Approach to Prioritizing Methods of Preventing Waste from the Residential Construction Sector in the State of Oregon

The purpose of this project by Oregon Department of Environmental Quality was to evaluate the environmental benefits of potential actions aimed at reducing material use and preventing waste during the design, construction, maintenance, and demolition of residential buildings within the state of Oregon. Within this report, the phrase waste prevention practices is used to describe practices that reduce material use or reuse materials - and subsequently reduce waste generation.

Buy Clean Washington Study

The Buy Clean Washington Study presents embodied carbon policies and proposes methods to categorize structural materials and report structural material quantities and origins.

LCA for Low Carbon Construction: Estimates of Embodied Carbon for Mechanical, Electrical, Plumbing, and Tenant Improvements

This study is an extension of the Life Cycle Assessment (LCA) for Low Carbon Construction Project. The Oregon Department of Environmental Quality selected mechanical, electrical, and plumbing (MEP) and tenant improvement (TI) as research topics of interest to investigate because there is very little data on these environmental impacts. This study presents estimates of material quantities and environmental impacts for commercial office buildings in the Pacific Northwest. This study is funded by the Charles Pankow Foundation, the Oregon Department of Environmental Quality, and Skanska USA.