Module B: The Use Phase Carbon Hot Zone
Most EPD chats orbit raw materials, yet for many products the bigger climate bill arrives after the ribbon-cutting. Module B captures every kilowatt, filter swap, and late-night maintenance call across decades of service life. Nail this slice of the LCA and specifiers see a product that keeps emissions low long after installation.
Module B in plain English
Module B tracks what happens during a product’s working life: routine upkeep, repairs, energy, water, even a future facelift. EN 15804 labels it the use stage and splits it into seven sub-modules, B1 through B7 (EN 15804, 2024). Think of it as the season-by-season stat sheet after the transfer window closes.
Why the spotlight matters
Operational carbon still delivers roughly 27 % of global building emissions (GSA, 2025). Owners chasing science-based targets scrutinise those numbers, and project teams reward products that keep the meter spinning slower. A tidy Module B can tip a bid when LEED v5 or BREEAM credits hinge on use-phase impacts.
The B1–B7 lineup
- B1 Use: normal operation (no extra inputs).
- B2 Maintenance: cleaning, inspections, consumables.
- B3 Repair: fixing minor failures.
- B4 Replacement: swapping components at end of service life.
- B5 Refurbishment: planned upgrades that reset the clock.
- B6 Operational energy: electricity, fuels, on-site generation yields.
- B7 Operational water: potable, grey, treatment energy. This table-stakes detail shows buyers you have logged the hidden costs they hate discovering later (Circular Ecology, 2024).
Forecasting fifty years without a crystal ball
PCRs let you anchor scenarios to a reference service life. Pick peer-reviewed data or field records, then document every assumption so reviewers can follow your math. Reliable consumption benchmarks are improving fast, yet gaps remain for niche products; flag them rather than fudging numbers.
Data capture without the spreadsheet drag
Pull energy curves straight from BMS exports, round up maintenance SOPs from the service desk, and re-use the bill of materials already prepared for warranty docs. Centralising those feeds early means your LCA consultant spends hours interpreting, not chasing, data.
When can you skip it?
If the product uses no energy, water, or consumables, and requires zero planned maintenance, Modules B2–B7 may default to zero. You still need to state that explicitly so verifiers do not assume an oversight. Being silent is risky.
The takeaway
Module B turns a static EPD into a living projection. Handle it with the same rigor you devote to sourcing recycled steel, and your spec sheet reads like a promise, not a guess. Your future-self—and future clients—will thank you, eventualy.
Frequently Asked Questions
Which Module B sub-modules are mandatory for a non-energy using product?
B1 must always appear. B2–B7 can be reported as zero only when the PCR and justified scenarios show no maintenance, repair, replacement, refurbishment, operational energy, or water demand.
How do I choose a reference service life (RSL) for Module B calculations?
Lean on field data, component warranties, or peer-reviewed literature. Document the source and rationale; auditors look for traceability more than a perfect number.
Can smart-meter data reduce Module B uncertainty?
Yes. Hourly or sub-hourly readings allow load profiles that beat generic benchmarks, cutting variance and strengthening the EPD’s credibility.
Does refurbishing a facade count under B5 if it alters energy use?
Yes, include material and labor impacts and any operational energy shift triggered by the refurbishment.
About the Author
Eric works at the intersection of sustainability, regulation, and business strategy, helping manufacturers navigate the evolving landscape of EPDs and LCAs. Having spoken with hundreds of teams across North America, brings a deep understanding of what drives ROI, what regulators are asking for, and how companies can stay ahead with smart, scalable approaches to environmental reporting.
