Team Floor renovation

Door reuse in renovation

Building waste, including your doors

Door reuse is not a CSR initiative: it is a technical and economic trade-off that becomes profitable beyond 25 removable doors, under NF S 31-080:2006 and the AGEC law since 2022. Below this threshold, the fixed cost of auditing and laboratory requalification exceeds the price of a new EI30 door. Careful removal, workshop restoration and reinstallation after PEMD diagnosis make it possible to retain the EI30 or EI60 fire-resistance and Rw 32 to 38 dB acoustic performance on a large share of the audited doors. Kytom, founded in 2006, deploys this protocol with a workshop less than 80 km from the site and unit-level traceability enforceable against inherent-defects (dommages-ouvrage) insurers. This report details technical thresholds, requalification costs, carbon savings based on INIES and regulatory points of caution.

The building sector generates 42 million tonnes of waste per year in France (ADEME, Building waste – key figures 2023), a significant portion of which comes from commercial fit-outs, renewed every 7 to 10 years. Since 2022, the AGEC law has required a Products Equipment Materials Waste (PEMD) diagnosis for operations larger than 1,000 m² or for demolitions, placing reuse at the heart of the renovation strategy.

Interior doors weigh 25 to 45 kg each and concentrate a high carbon load per kilogram of material, linked to wood species, glazing and hardware:

a limited but recurring share of the total mass of a commercial fit-out
25 to 60 kg CO2 equivalent avoided per reused door (EPD for interior wood doors, INIES database, 2023 data)
several hundred kilograms of landfilled waste avoided on a typical operation of 800 to 1,200 m²

For the architect and the IRB: reuse becomes an argument for the building permit application. Beyond the carbon assessment, retaining existing joinery feeds the project’s heritage narrative in ZPPAUP, AVAP or ABF perimeters, where the regional heritage commission values material continuity. Real estate departments see it as a combined lever to reach the -40 % milestone in 2030 of the tertiary decree, to feed CSRD reporting and to capture BREEAM In-Use, HQE and WELL credits that now reward the reused-material rate.

From how many doors does reuse become profitable?

The Kytom break-even threshold is at least 25 removable doors on a single site. Below this, the fixed cost of auditing (2 to 4 days), of transport to the workshop and of laboratory requalification (800 to 1,500 EUR per type) exceeds the price of a new EI30 door (380 to 550 EUR including installation). Beyond 25 units, the unit cost drops and the carbon saving, documented on the INIES database, becomes an argument in the building permit application.