How do I calculate the carbon footprint of a steel door?
Weigh the steel sheet and frame in one door, including cutting scrap, and apply your steel supplier's factor. Add infill such as honeycomb paper or rockwool, powder coating and oven fuel, welding and press electricity, hardware and packing. Divide by doors dispatched. Steel is usually most of the total.
Materials
- Galvanised or cold rolled sheet for leaves and frames.
- Infill: honeycomb paper, PU foam or mineral wool for fire doors.
- Hinges, locks, vision glass and gaskets.
Process
- Shearing, punching, press brake and welding electricity.
- Pretreatment and powder coating, with oven LPG, PNG or electricity.
- PU foam injection where used.
Per door
Report each size and type separately: a fire-rated door carries more steel and infill than a standard one.
Worked example: steel door plant per door (one month)
- Electricity: 25,000 kWh x 0.710 = 17,750 kg CO2
- Powder oven PNG: 3,000 SCM x 2.05 = 6,150 kg CO2
- Doors dispatched: 1,500
- Plant total: 23,900 / 1,500 = 15.93 kg CO2 per door
- Add sheet steel, infill and hardware for the full figure
Inputs are illustrative; use your own bills and production records.
What Senseible does here
Senseible reads the plant's electricity bills (CEA grid factor 0.710 kg CO2 per kWh, CO2 Baseline Database version 21.0) and fuel invoices (IPCC 2006 defaults) into a fingerprinted Scope 1 and 2 record, the plant-level input to a per-unit figure. Bought-in materials go to the supplier evidence trail; product reports are self-declared drafts.
Sources: GHG Protocol Product Standard, ISO 14067:2018, Carbon footprint of products (iso.org), IPCC 2006 Guidelines, Volume 2 Energy (fuel defaults), CEA CO2 Baseline Database, version 21.0
Last reviewed 2026-10-20.