The U.S Green Building Council (USGBC) recently closed the public comment feedback period for LEED v5. With decarbonization elevated as one of three focus areas of impact for next version of LEED (the other two being quality of life along with ecological conservation and restoration) and a newly proposed prerequisite requiring teams to assess projects for embodied carbon (optimization currently drafted as being separate, optional credit), the rating system draft for Building Design and Construction (BD+C): New Construction (NC) promises to bring embodied carbon calculations from niche optional exercise to mainstream practice much in the way the rating system has already accomplished with building energy modeling, mechanical commissioning, and building enclosure commissioning. 

The marketplace of tools for measuring embodied carbon has blossomed recently, but only because leaders across the AEC industry have been hard at work for years. From leading architecture firms, to world-class engineering teams, to coalescing efforts across academia, a variety of platforms are being launched that will change the way we assess our buildings for global warming potential. 

The following is an exhibit of over twenty tools (many of which are free) that can help your team examine, disclose, and optimize your next building project for embodied carbon. 


Athena EcoCalculator

Developed by the non-profit Athena Sustainable Materials Institute (ASMI), the EcoCalculator is a structured Microsoft Excel workbook that provides instant LCA results for hundreds of common building assemblies. Results are displayed for embodied fossil energy use and several other impact measures including global warming potential, acidification potential, eutrophication potential, and smog potential. This simple, preliminary analysis tool is equipped with predefined building assemblies (for commercial or residential construction) that have previously been assessed in the more robust Athena Impact Estimator for Buildings. (


Athena Impact Estimator for Buildings

The Impact Estimator for Buildings is a stand-alone program from ASMI that allows users to model their own custom assembly and envelope configurations, with flexibility to handle proposed designs and existing buildings. A more advanced platform than the EcoCalculator, the Impact Estimator allows the user to input energy simulation results to calculate their operating effects alongside the embodied effects. The software was developed specifically for the North American construction industry. Its inherent LCA methodology, cradle-to-grave system boundary, and inventory datasets are compatible with requirements for LEED, Green Globes, IgCC, and CALgreen. (



Developed by the Embodied Carbon Lab at Thornton Tomasetti and leveraging the firm’s embodied carbon calculations on over 600 projects, Beacon is a Revit plug-in designed for structural engineers that provides quick, high-level feedback on the anticipated embodied carbon of a building’s structural system. The tool rates a model’s embodied-carbon figures against the Carbon Leadership Forum’s (CLF) Embodied Carbon Benchmark Study results. Beacon is free via open-source license through the Massachusetts Institute of Technology (MIT). (


BEES (Building for Environmental and Economic Sustainability)

Developed by the National Institute of Standards and Technology (NIST), an agency of the U.S. Department of Commerce, BEES assists in the selection of environmentally-preferable building products by generating a simple overall score. It weighs environmental and economic life-cycle performance scores with relative scales specified by the user. Global warming, acidification, nitrification, natural resource depletion, indoor air quality, and solid waste impacts are included. (


Buildings and Habitats Object Model (BHoM)

Buro Happold launched BHoM in 2016 as a collaborative computational development project and collective. The collective co-creates and shares code. Among various initiatives, BHoM offers an open-source computational toolkit for integrated building performance analysis. The free toolkit includes a module that focuses on WBLCA and facilitates comparison of building systems, assemblies, and materials. This open coding initiative supports analysis via Grasshopper/Rhino, Excel, and other formats. It also supports BIM integration and allows the direct import of material quantities. BHoM connects BIM quantities to LCA data from various other open-source databases including EC3 and the Inventory of Carbon and Energy (ICE) database from the University of Bath's Sustainable Energy Research Team (SERT). (


Building Life-Cycle Cost (BLCC) Programs

Developed by NIST for the Federal Energy Management Program (FEMP), BLCC provides a computer-based structure for life-cycle cost analyses in conformance with the Whole Building Design Guide (WBDG) Handbook 135: Life-Cycle Costing Manual for the Federal Energy Management Program. (


Carbon Avoided: Retrofit Estimator (CARE) Tool

Developed by the non-profit Architecture 2030, the CARE Tool is a free, cloud-based platform that allows users to quickly estimate and compare the embodied and operational carbon impacts of reusing an existing building, retrofitting the structure, or replacing it with new construction. Avoided carbon impacts and benefits are conveyed through graphic outputs that lend to early-stage project decision-making. (


Construction Carbon Calculator

The Construction Carbon Calculator is a free, simple web-based carbon calculator for high-level estimates of whole-building carbon impacts using only minimal project inputs. The calculator is hosted on the BuildCarbonNeutral website. Both the calculator and website were developed in a cooperative effort led by Mithun and the Lady Bird Johnson Wildflower Center at the University of Texas at Austin with assistance from the University of Washington Program on the Environment. (


Cove.Tool Carbon Feature

The developers at cove.tool have added the carbon feature to its cloud-based automated building performance analysis platform. Design teams can explore a variety of design inputs to assess their project's lifecycle carbon profile (embodied and operational). This feature permits a whole building embodied carbon assessment and exhibits a breakdown per component system (i.e., superstructure, substructure, enclosure, and interior). Teams may baseline a project's total carbon emissions using generic values from the Carbon Leadership Forum (CLF) and the Embodied Carbon in Construction Calculator (EC3). However, users may optimize design solutions using a project assembly browser or utilize specific products from the EC3 tool's growing EPD library. (


Embodied Carbon in Construction Calculator (EC3)

Originally developed by Skanska and C Change Labs, today the EC3 tool is the flagship service of the nonprofit Building Transparency. EC3 is a free, open-source, online database of construction EPDs along with an integral building impact calculator. The EC3 tool can be utilized during the design and procurement phases of a construction project to assess a project’s overall embodied carbon emissions, facilitating the specification and procurement of the low carbon options. (


Early Phase Integrated Carbon (EPIC)

The EPIC assessment tool allows users to examine the lifecycle carbon impact of building materials options. Developed by the architecture firm EHDD, this free cloud-based tool is meant to support early design decision-making. This east-to-use program combined regionally-specific data, methodical projections, peer-reviewed findings, and sensible assumptions to provide users with a quick and graphically-rich assessment of the relative impact of a variety of design strategies on embodied, operational, and landscape carbon footprints. (


Hawkins Brown Emission Reduction Tool (H\B:ERT)

Hawkins/Brown (H/B) partnered with the University College London (UCL) Institute for Environmental Design and Engineering (IEDE), through their Engineering Doctorate program, to develop their Emissions Reduction Tool (ERT). The H\B:ERT is an open-source tool available as a Revit plug-in. The program facilitates quick analyses of the life cycle emissions of whole buildings, building structures, enclosures, and/or materials. (


i-Tree Calculator

i-Tree is a free, cloud-based software platform provided by the United States Department of Agriculture (USDA) Forest Service that allows users to assess the environmental services that trees may provide on a specific project. Design teams can use i-Tree to quantify the aggregate lifecycle carbon sequestration of trees on a project. i-Tree is in the public domain through the i-Tree website. (



Payette designed the Kaleidoscope web-based resource to supplement (not replace) whole-building LCA modeling exercises in the earliest design phases. The resource allows designers to quickly compare the embodied carbon impacts of various building materials and systems to make better-informed design decisions. (


One Click LCA

The global parent tech company, One Click LCA Ltd. (formerly Bionova Ltd.), offers a range of accessible, cloud-based life cycle assessment tools that draw upon more than 200,000 construction LCA datasets, supports a wide range of international standards and certifications, and is compatible with most BIM software platforms including Revit and iTwin. Their premiere and eponymous all-in-one building design and construction tool is subscription-based and offers a range of tools to assist in early design decisions, procurement, and green building certification. (


One Click LCA Planetary

Planetary is a free cloud-based tool from One Click LCA Ltd. That allows users to calculate and benchmark embodied carbon impacts and material efficiency of building designs. The major limitation for Planetary is that it only assesses the ten most carbon-intensive and significant materials categories in construction. (



Climate Positive Design, a nonprofit research initiative founded by CMG Landscape Architecture principal Pamela Conrad, launched the free cloud-based Pathfinder tool in 2019 to help design teams estimate the carbon footprint and time to carbon neutrality for landscape designs based on particular parameters. The tool uses data from the Athena Impact Estimator for Buildings and the U.S. Forest Service to determine a Climate Positive score, which indicates when the project’s carbon sinks will offset its embodied and operating carbon footprint. (


Tally Climate Action Tool (tallyCAT)

Developed by Building Transparency, tallyCAT serves a free and open-access Revit plug-in that facilitates the export of material quantities from Revit to EC3 and enables synchronization between the platforms. tallyCAT allows users to select materials from the EC3 database and explore embodied carbon reduction opportunities and export figures and reports to communicate to project teams and stakeholders. (


Tally Life Cycle Assessment (tallyLCA)

The product of a joint development project between KierranTimberlake’s research affiliate KT Innovations, Sphera (formerly thinkstep), and Autodesk, Tally was acquired by the Building Transparency in 2021 and rebranded as tallyLCA in order to distinguish it from the tallyCAT platform. Tally is a Revit plug-in that allows a user to quantify the environmental impact of building materials for whole-building analysis as well as comparative analyses of design options. A user can define relationships between BIM elements and construction materials from the Tally database. The result is LCA on-demand, which can provide important decision-making information within the same timeframe, pace, and environment that building designs are generated. The outputs can be configured to support LEED compliance. (



Developed by ZGF in collaboration with the University of Washington’s Applied Research Consortium, the UpStream Forestry Carbon and LCA Tool is a free, Excel-based open-source life cycle calculator focused on wood, allowing users to assess biogenic carbon storage, forest carbon sequestration, and custom end-of-life scenarios. (


ZGF's Concrete LCA Tool

ZGF as released a free, Excel-based calculator for generating and comparing the LCA results of specific concrete mix designs using data from the National Ready Mixed Concrete Association (NRMCA) regional benchmark information and WBLCA data from TallyLCA. (