Module B: The Use Phase Reality Check
Manufacturers often obsess over A1–A3 raw-material numbers yet forget that specifiers keep scrolling to Module B. If you cannot show how a product behaves in the messy middle of a building’s life, you risk losing on bids that score whole-life carbon. The seven sub-modules track every kilowatt, gasket swap, and drop of rinse water once your product is installed. Nail them, and you turn an LCA line item into a powerful proof of performance.
Module B in One Sentence
Module B measures what happens after the product is bolted in place and before it heads for recycling or the landfill, capturing maintenance work, energy use, and tiny but costly leaks the owner pays for.
Why Module B Is Suddenly Non-Negotiable
EN 15804 +A2 made B1–B7 disclosure mandatory for most construction products published in Europe in 2024, and US specifiers have started asking for the same data to align with the new RICS whole-life carbon standard (RICS, 2024). Ignore these lines and you risk disqualification even if your upfront carbon shines.
The Seven Sub-Modules at a Glance
- B1 Use: direct emissions or substances released during normal operation.
- B2 Maintenance: routine cleaning, repainting, lubrication.
- B3 Repair: fixing damage or faults without full replacement.
- B4 Replacement: swapping the whole product or a key component.
- B5 Refurbishment: major upgrade that restores performance beyond simple repair.
- B6 Operational energy use: electricity, gas, or other fuels consumed by the product in use.
- B7 Operational water use: water required for function, cleaning, or humidification.
Energy vs Water: The Carbon Tug of War
Buildings still consume 32 percent of global energy and pump 34 percent of CO₂, with operational emissions alone hitting 9.8 gigatonnes in 2023 (UN Buildings Status Report, 2024). Even high-efficiency HVAC coils or low-pressure piping can shift the balance by several tonnes of CO₂e over a 60-year reference period. Water matters too: a recent Dutch study found that hot-water circulation pumps can add 4–6 kg CO₂e per square meter across B6 and B7 for multifamily projects (TNO, 2025).
Data Problems That Stall Projects
Operational profiles are rarely logged at the product level. Field meters aggregate whole systems, and maintenance schedules sit in PDF manuals no one reads. That gap forces LCA teams to plug generic values, which can inflate impacts by 15 percent or more compared with real-world measurements (World Economic Forum, 2025). We all seen how auditors react when defaults sneak in—suspicious looks, extra queries, time lost.
Quick Wins to Nail Module B Data
- Embed a QR code on the product that links to a digital logbook. Facility teams can upload work orders and energy readings in minutes.
- Specify test-bench energy draw during product certification. Those lab figures become defensible B6 inputs.
- Add sensor-ready ports even if clients rarely order them today. Retro-fits are ten times more expensive.
Specifiers Care, and They Check
Major contractors in the UK now apply a 10-point scoring bonus for products that prove B6 values are below 3 kWh per year per kilogram of material (BCIS, 2024). In the US, LEED v5 draft language rewards accurate Module B disclosures with up to two Innovation points. That is a free nudge onto the shortlist.
Take Module B Seriously, Beat the Market
Front-load the grunt work, capture real use-phase data, and your next EPD will read like a crystal-clear service manual. Bid teams love that clarity, owners save on utilities, and everyone avoids last-minute spreadsheet drama. Module B is not a footnote, its your mid-life badge of honor.
Frequently Asked Questions
What sub-modules fall under Module B in an EN 15804 compliant LCA?
Module B covers B1 Use, B2 Maintenance, B3 Repair, B4 Replacement, B5 Refurbishment, B6 Operational energy use, and B7 Operational water use.
Is Module B information mandatory for product-specific EPDs in 2025?
Yes. EN 15804 +A2 and the RICS WLCA 2nd edition both require B1–B7 reporting for most construction products, except where the PCR explicitly states otherwise (RICS, 2024).
How can manufacturers collect reliable B6 energy data without field meters?
Include certified test-bench measurements during product qualification or integrate low-cost IoT plugs that log kWh at the circuit level. These values are acceptable to most program operators because they come from calibrated equipment.
Does Module B impact LEED points?
LEED v5 (draft) proposes Innovation credits for accurate in-use carbon reporting, effectively rewarding robust Module B data.
About the Author
John brings a clear, research-driven perspective on the EPD, LCA and HPD space and keeps a close pulse on environmental trends and standards in North America, helping clients understand where the industry is heading and how to get there.
