FAQ ·
TallyLCA was the first LCA app that allowed designers to calculate the environmental impacts of their buildings directly in Revit®. It was originally developed by the architecture firm KieranTimberlake in the mid-2010s; then, in 2021, KieranTimberlake gifted tallyLCA to Building Transparency for its continued management, hosting, and development. It is focused on empowering higher-level design and material type choices that become the critical first step toward reducing environmental impact. Today, tallyLCA has approximately 3,500 users in the AEC industry.
As demand for embodied carbon accountability increases, driven by policy, client expectations, and firm commitments, design teams need a continuous workflow from concept through construction. This acquisition allows C.Scale to deliver that end-to-end capability at a critical moment for market adoption.
200+ architecture and engineering firms are using C.Scale to engage with decarbonization efforts at the earliest stage of a project; setting robust climate goals and testing strategies to identify the most impactful pathways for building decarbonization on every project. C.Scale’s lightweight, accessible cloud interface enables a diverse set of design actors to engage with carbon accounting and develop insights without getting bogged down with a detailed BIM model. C.Scale’s predictive modeling approach enables users to identify and evaluate strategies much earlier in the design process, so teams can focus their energy and resources on decarbonization efforts that really make a difference.
But designers looking to convert the ambition represented in their models into material outcomes are universally frustrated by the lack of continuity in the current workflow. Tally continues to be the best way to intelligently extract a “bill of materials” from a Revit model and apply environmental attributes such as carbon intensity to the elements. Linking C.Scale and Tally addresses this major gap in the industry: disconnected workflows between early-stage carbon modeling and detailed material-level analysis.
It reflects the broader shift of WBLCA becoming standard practice. Voluntary programs like LEED v5 are increasingly weighted towards whole life and embodied carbon reductions, while regulatory frameworks in states like California and Massachusetts, and cities like Toronto and Vancouver, are ratcheting up their LCA requirements at the time of permit. With over 1,000 architecture firms committed to carbon-neutral design through AIA 2030, the industry is moving toward integrated, data-driven decision-making across the full building lifecycle.
Tally 2.0 is the next generation of TallyLCA. Version 2.0 will include a comprehensive update of background LCA data across the tool to support long-term maintainability, improve data access, and align with industry standards. The tool will maintain Tally’s intuitive interface for defining quantity survey methods and associating Revit materials with LCA datasets.
In addition to traditional static Excel and PDF exports, the new version will enable users to preview tabular and graphical results through an interactive in-tool interface, providing rapid feedback and interpretation. Tally 2.0 will continue to support all of the main features of TallyLCA, including bill-of-material exports to EC3. A wide range of new features is planned, including expanding access to industry and product EPDs through EC3, direct connections to the C.Scale platform, and offering greater flexibility for comparative studies.
Existing Tally 1.0 licenses remain fully valid and unaffected by the transition. BT remains committed to supporting 1.0 license holders through this period. BT will continue to collect and retain all current and new license fees for Tally 1.0 until the release of Tally 2.0, so renewing your license is business as usual.
Active Tally 1.0 license holders at the time of Tally 2.0's release will receive complimentary access to Tally 2.0 for the remainder of their 1.0 license as a thank-you for their continued engagement. Staying current on your license is the best way to ensure you're positioned to take advantage of that.
Tally 1.0 remains distinct from C.Scale; please visit https://choosetally.com/ to sign up for a demo or full license. Meanwhile, C.Scale is eager to get its users into Tally 2.0 as soon as it is ready for BETA and will be announcing access options soon.
Work to complete the development of Tally 2.0 has already begun. We aim to release Tally 2.0 by the end of Q3 2026, in time for Greenbuild in October. More updates will be forthcoming as we get closer to completion.
Building Transparency is concentrating resources on EC3 2.0 development to expand global coverage, improve data quality, and support emerging standards, procurement programs, and regulations. These efforts will help to advance peer tools like C.Scale and Tally. Rather than competing feature-for-feature with commercial tools, EC3 2.0’s release this year will strengthen Building Transparency’s role as the neutral, nonprofit backbone supporting governments, enterprises, researchers, and software platforms.
EC3 2.0 will include:
AI-Enabled Data Quality and Ingestion Systems
Cloud-Agnostic Architecture Modernization
Expanded Global EPD Coverage and Interoperability
Strengthened Material Comparison and Benchmarking
Assembly Builder and Structured Workflow APIs
Expanded Environmental Impact Categories
Improved Life Cycle Stage Coverage
Learn more about the goals and scope of EC3 2.0 here.
No. The new version of the tool will maintain integration with EC3, supporting the export of material quantities from Revit to EC3 and enabling synchronization between the two. This allows users to see in real time the impact of their decisions on a project’s overall carbon footprint.
They are different, but complementary tools. Together, they support low-carbon decision-making across the whole building lifecycle, from concept through construction:
EC3: Open-access data infrastructure (EPDs, product benchmarking, project planning)
Tally: BIM-based LCA tool for detailed analysis
C.Scale: A whole life carbon assessment platform connecting design intent from the earliest stages to material outcomes through construction.
For C.Scale: The immediate focus is developing and launching Tally 2.0 and deepening integrations with C.Scale’s platform. Longer term, the focus is on expanding capabilities, supporting more users, and advancing industry-wide adoption of low-carbon design.
For BT: Building Transparency is concentrating resources on EC3 2.0 development this year to expand global coverage, improve data quality, and support emerging standards, procurement programs, and regulations.