EN 15804 divides a construction product’s life into information modules: the product stage A1 to A3, the construction stage A4 to A5, the use stage B1 to B7 and the end of life stage C1 to C4. Module D reports benefits and loads beyond the boundary. Cradle to gate covers A1 to A3, cradle to grave modules A, B and C.
The modules and the four stages
An Environmental Product Declaration to EN 15804 does not report a single number. It splits a construction product’s life into information modules, grouped into four life cycle stages, so buyers can compare like with like and see where impact falls.
| Stage | Modules | What they cover |
|---|---|---|
| Product stage | A1 to A3 | A1 raw material supply, A2 transport to the manufacturer, A3 manufacturing |
| Construction process stage | A4 to A5 | A4 transport to the site, A5 installation into the building |
| Use stage | B1 to B7 | Use, maintenance, repair, replacement, refurbishment, and operational energy and water use |
| End of life stage | C1 to C4 | C1 deconstruction and demolition, C2 transport, C3 waste processing, C4 disposal |
Module D and the boundaries
Beyond those four stages sits Module D, benefits and loads beyond the system boundary, which reports the potential from reuse, recovery and recycling of materials once they leave the product system. Module D is always reported separately, and modules A to C are never added into it, because it rests on a different system boundary. The modules also map onto the boundary terms an LCA uses: cradle to gate is A1 to A3, and cradle to grave is modules A, B and C together, with Module D outside that total. The LCA guide sets out the cradle to gate and cradle to grave boundaries in full.
Upfront, embodied and whole life carbon
The modules give precise meaning to terms that are often used loosely. Upfront carbon is modules A1 to A5, the impact before the product is in use. Embodied carbon is the material related impact across modules A to C, excluding the operational energy and water of modules B6 and B7. Whole life carbon is modules A, B and C together, with Module D reported alongside. Under the A2 revision the minimum an EPD declares is the product stage, the end of life stage and Module D. The life cycle assessment service builds the study to ISO 14040 and ISO 14044 and prepares the EPD to ISO 14025 and EN 15804, verified by an independent programme operator, and a LCA discovery session scopes the modules a product needs.
Sources: ISO 14025 · ISO 14040 · RICS Whole Life Carbon Assessment