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Real-Time LCA aligns with three families of ISO standards: the parent LCA methodology in ISO 14040:2006 and ISO 14044:2006, the building-level framework in ISO 21931-1:2022, and service-life planning in the ISO 15686 series. All are available for purchase from ISO.org. The European calculation method EN 15978 operationalises these for buildings in Europe.

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ISO 14040 and ISO 14044 — LCA principles

ISO 14040 sets out the principles and framework of life cycle assessment; ISO 14044 specifies the requirements and guidelines. Together they define the four LCA phases used implicitly across every calculation in Real-Time LCA:
  • Goal and scope definition — captured per project (functional equivalent, reference study period, system boundary).
  • Life cycle inventory analysis — built from the Building Component Inventory and the linked EPD or generic dataset for each material.
  • Life cycle impact assessment — characterisation per EN 15804+A2 indicator factors.
  • Interpretation — presented through the project dashboard, emissions-over-time view, and report exports.

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ISO 21931-1:2022 — framework for buildings

ISO 21931-1 provides the international framework for environmental performance assessment of buildings and civil engineering works. It defines what a building-level assessment must cover (functional equivalent, system boundary, modules, indicators) without prescribing the calculation rules themselves. EN 15978 is the European calculation method that conforms to this framework. Real-Time LCA implements EN 15978, so projects produced in the platform are simultaneously consistent with ISO 21931-1. The 2022 revision of ISO 21931-1 aligns more closely with the EN 15804+A2:2019 indicator set; the in-progress revision prEN 15978-1 is expected to bring EN 15978 into the same alignment.

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ISO 15686 — service life planning

The ISO 15686 series covers service life planning for buildings and constructed assets. The data relevant to Real-Time LCA is the reference service life (RSL) of each construction product, which drives module B4 (replacement) calculations: a product with an RSL shorter than the project’s reference study period is replaced one or more times within the study period, and each replacement event re-emits the embodied carbon of the new product. Real-Time LCA uses national lifetime tables — for example the BR18 lifetime table for Denmark — as the source of RSL values. See Assumptions and defaults for how overrides work at project level.