Research Project:

CLF WBLCA Benchmark Study v2

The Carbon Leadership Forum is pleased to announce the beginning of a multi-year project to develop a robust and harmonized database of WBLCA benchmarks. The pilot phase of this project is officially underway.


In 2017, the CLF published the Embodied Carbon Benchmark Study for North American buildings. Since then, WBLCA has grown rapidly in the AEC industry, and it has become clear that more robust and reliable benchmarks are critical for advancing work in this field. This new CLF WBLCA Benchmark Study (Version 2) will build upon research and insights from the 2017 study. The project will expand our research methodology and result in geographically and typologically-specific benchmarks for buildings, systems, and assemblies modeled with consistent scope and background data. This will allow designers and decision-makers to set reliable embodied carbon targets and understand the potential for reduction throughout the design and construction processes.


Problem Statement

Currently, it is difficult to set robust targets or benchmarks for the embodied carbon of buildings, components, or materials due to the lack of a robust collection of WBLCA models. Existing studies have been based on a very small number of calibrated models, or large low-quality and non-harmonized datasets, making it difficult to understand whether variability stems from modeling practice, background LCI data, or actual design decisions.

Over the last 5 years, there has been rapid adoption of WBLCA by architecture and engineering firms. However, there is currently no centralized repository of WBLCA models from which to conduct research.

This project will fill a critical gap in the AEC industry and help enable architects, engineers, policy makers, and the entire design community to work towards realistic and measurable embodied carbon reductions at the building scale.

The pilot phase of this project is officially underway, and the CLF is actively seeking collaborators from both practice and academia to ensure that the data gathered for the study is sound, that the results are properly analyzed, and that the findings are communicated in ways that best support the AEC community in effectively driving decision-making and decarbonization in the built environment. 

CLF WBLCA Benchmark Project Logo

Pilot Phase

In order to develop a future high-quality and harmonized dataset of WBLCA models, the pilot phase of this project will refine WBLCA modeling guidelines, establish reporting standards, and build infrastructure for the first round of data collection. This first round of collection will be used for research purposes, and will—by design—be small and focused. The study will examine the variability of collected LCA results by building characteristics (use, location, height, construction type, etc.) design strategies employed, and materials selected. This pilot dataset will be used to inform upcoming stages of a multi-year CLF WBLCA Benchmark Study V2 and data repository.

The pilot dataset will be assembled from buildings that have been modeled and documented using Revit, with material assignments and quantities calculated using the Tally LCA plug-in. All models collected will be harmonized in their modeling practice, nomenclature, structure, background data, scope, and QA-ed by the research team and pilot phase collaborators. This consistency of modeling practice will allow the researchers to focus on trends and insights in the model results, explore modeling practice realistic to architecture firms working on real projects, set preliminary WBLCA benchmarks with uncertainty ranges, and explore and reprocess model results using a range of methods, software, and background data.


Research Questions

  • What is the availability of WBLCA models produced by firms during design?
  • How do the GWP results of this pilot dataset compare to existing, coarse WBLCA benchmarks?
  • What are typical preliminary EC figures per building element and component (structure, envelope, interiors, site, etc.)
  • How can the CLF support collection and analysis of WBLCA data while respecting the need for privacy and sensitivity in sharing building models and other articles of service?
  • What additional resources and questions are appropriate for future phases and more reliable benchmarks?



This benchmark study aims to pair rigorous, academic research and data analysis methods with WBLCA models of real projects, produced by architects and engineers in realistic conditions. This will not be a collection of theoretical reference buildings, but a relatively small sample of realistic building projects that can be used to gain insight into how a harmonized, database of WBLCA models could be collaboratively produced, assessed, published, and maintained over time.



  • WBLCA Study modeling guidance and reporting templates
  • Feedback on WBLCA practice from pilot firms
  • Pilot dataset of aligned LCA models and model results
  • Material quantity estimates and detailed building attributes for each building model
  • Gap analysis and goal definition for Phase 2 Research


Preliminary Schedule

The CLF officially started the pilot phase of this project in March of 2022. This phase is expected to run for 6 months. It will be a critical step in developing the necessary framework and infrastructure for future phases of the project. The CLF is presently seeking funding and support for future phases of this multi-year effort to develop a larger and more rigorous WBLCA dataset, publish benchmarks, and create a North American reporting database.


Open Call for Participants

The CLF is actively seeking collaborators to help support this project. If you are interested in participating in the study or simply want to stay up to date on its progress, please fill out this Participant Questionnaire. The questionnaire asks for basic information about your organization, your level of interest, and your capabilities for participating in the study. Responses from the questionnaire are confidential and will be used internally by the CLF to help inform the scope and structure of the project.

For general inquiries about the project please email

Project Updates

October 2022

The project team has recently wrapped up our initial pilot phase of the WBLCA Benchmark Study which focused on reviewing existing literature and building internal data infrastructure.

During the pilot phase, we:

  • Developed a process for architecture or engineering firms to easily submit detailed Tally models, Bill of Materials, and other project information.
  • Developed infrastructure to enable robust data analysis at a building, assembly, and material scale.
  • Conducted extensive background research on WBLCA benchmarking and benchmark development in the US and Europe.
  • Tested data collection templates and reporting processes.
  • Identified stakeholders and interested parties for future participation.

In the next phase of the project we will expand the project to:

  • Include a larger sample set of firms, projects, and WBLCA tools.
  • Build upon the work completed in the Pilot Phase.
  • Establish stakeholder working groups for technical advisory, communications, harmonization, and more.

If you’d like to get involved, our Participant Questionnaire remains active. You can also reach out to with any project-specific questions. We will continue to provide project updates through our website – stay tuned for more information!