For embodied carbon calculations, CIBSE TM65 will be updated to incorporate the new IC+ Database embodied carbon factors for materials, replacing the ICE Database factors currently referenced.
The IC+ database is the new commercial embodied carbon database launched by Circular Ecology. It is being rolled out to replace the commercial usage of the widely used Inventory of Carbon and Energy (ICE) Database.
CIBSE recognises that this is an important change to the factors used in CIBSE TM65. We are working with Circular Ecology to make the transition as smooth as possible for CIBSE TM65 users.
Stay tuned for how the new factors will be incorporated into CIBSE TM65 guidance and tools.
CIBSE TM65 transition to IC+ Database - FAQs
By 13 November 2026, CIBSE will have updated all CIBSE TM65 publications in line with the new IC+ Database material factors.
Potentially, yes - if a material's generic carbon factor is revised upward or downward in the update, a product's calculated embodied carbon could shift without any change to the product itself.
Existing users who have already purchased the tool will be able to download updated versions at no extra cost.
Users of CIBSE's official CIBSE TM65 content will not need a license from Circular Ecology for IC+. You will be able to use CIBSE's content to carry out calculations using the most up-to-date material carbon factors.
CIBSE Certification offers the embodied carbon verification (ECV) scheme for manufacturers wishing to get their CIBSE TM65 calculations verified. As part of this service, CIBSE Certification will support its ECV customers during the IC+ database transition, and ensure certified data is updated annually (if needed) as part of its annual surveillance activities.
It is recommended that existing CIBSE TM65 assessments are updated following the transition to the new IC+ database, as the update to the carbon factors is considered a material change.
CIBSE will be releasing a new version numbering system for CIBSE TM65. The current version is 1.6; CIBSE will be moving to 1.7.0 with the most recent alignment with IC+ Database material factors. The new version number will follow the pattern X.Y.Z where:
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X – Methodology version
Applied when changes affect fundamental comparability:
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Revision to the CIBSE TM65 calculation methodology
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Y – Input Factors version
Applied when changes alter embodied carbon results without changing the overall methodology structure:
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Update to carbon emission factors for materials
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Update to carbon emission factors for energy sources
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Update to refrigerant Global Warming Potential (GWP) factors or leakage rates.
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Z – Patch
Applied when a bug is fixed within the TM65 methodology, or associated calculation engine:
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Bug fix in the CIBSE TM65 calculation engine or methodology
No. The updated material factor name will be visible in the new Excel tool, but not the values, as per the terms of use from Circular Ecology.
Continued commercial/non-educational use of ICE data past the 30th of September 2026 is not licensed. If your CIBSE TM65 workflow, calculator, or internal tool pulls ICE factors, you'll need to migrate to IC+.
CIBSE is continuing to advance the CIBSE TM65 offering with the following projects being actively pursued:
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Development of a CIBSE TM65 software engine, which will be available via API and CIBSE hosted software. With the changes to the backend material carbon factors used in CIBSE TM65, CIBSE hopes to offer automatic updates to factors across its software suite for those using official CIBSE TM65 tools in the future.
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Aligning CIBSE TM65 product taxonomy with the Aligned Data Specifications Alliance, and CIBSE's Guide M.
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Processing CIBSE TM65 Data in the pursuit of benchmarking.
Impact on CIBSE Certification's embodied carbon verification (ECV) scheme
The Embodied Carbon Verification (ECV) scheme is CIBSE Certification's ISO 17065-based scheme that independently verifies manufacturers' TM65-based embodied carbon claims where EPDs aren't available. It's separate from the database question, but not unaffected — ECV certificates are built on CIBSE TM65 calculations, which draw on the same generic factors. CIBSE Certification will be working with all its ECV customers to update CIBSE TM65 calculations to be in line with the new IC+ database.
No - ECV is about independent verification of a claim, not about which database underlies it.
CIBSE Certification maintains a public ECV register of verified products (launched in October 2025), which remains the authoritative source regardless of the database transition.
Alongside CIBSE Certification's ECV Register, CIBSE hosts verified products on industry-recognised design and calculation software platforms. CIBSE has recently announced a partnership with Cerclos, enabling verified CIBSE TM65 data to be hosted within eTool, see more here