Eco-design of offices: designing low carbon from the very first sketch

For the majority of commercial projects we support in renovation or lease fit-out, the enforceable framework is not the 2020 environmental regulation but the triptych + CSRD + Article 29 of the Energy and Climate Law. This distinction changes the documentary scope and the material decisions from phase 1 onwards.

The tertiary decree imposes -40% energy consumption by 2030 and -60% by 2050 on buildings over 1,000 m². Interior fit-out now falls within the scope via CSRD obligations and Article 29 of the Energy and Climate Law. Three texts structure your compliance:

• NF EN 15978: life cycle analysis across 5 phases (production, transport, installation, operation, end of life).
• 2028 regulatory thresholds: the 2028 regulatory thresholds require new low-carbon construction solutions, set out in the BBCA Renovation label for existing buildings.
• Usable floor area and quality of use standards: linked to articles R4211 to R4217 governing workplaces.

The EPDs hosted on the INIES database remain the only reference enforceable for CSRD reporting. The majority of new commercial leases now include ESG clauses. Below 300 m² outside a lease, with no CSRD commitment or targeted certification, a simplified bio-based materials scoping is generally sufficient. The full approach is justified from 500 m², or where an asset is targeting a recognised environmental certification such as HQE.

Our method produces quantifiable effects at four levels: a markedly reduced fit-out carbon footprint, contained supply costs thanks to reuse, enhanced rental value on certified assets, and significantly improved employee satisfaction.

In practice at Kytom, the rental premium linked to certification is not an automatic given. It materialises on assets in high-demand areas (Paris CBD, Lyon Part-Dieu, La Défense, tier-1 metropolises) and subject to effective certification, not merely an eco-designed approach. On secondary assets, the real lever lies elsewhere: avoided carbon enforceable for sustainability reporting, employer brand, compliance with the 2030 tertiary trajectory.

The reuse of partitions, suspended ceilings and furniture offsets the occasional additional costs of bio-based materials. Indoor air quality, handled according to our standards of comfort and workplace health, contributes to improved employee satisfaction in eco-designed spaces. Timelines remain identical to a conventional project, provided sourcing is anticipated from the programming stage.

Commercial honesty requires us to name the situations where our 5-phase method consumes more value than it produces.

Project under 300 m² outside a lease. Phase 1 of carbon diagnostic, life cycle analysis and verified environmental product declarations absorbs a large share of the consulting budget on these formats. The carbon ROI remains low. We recommend a lighter approach centred on bio-based materials and furniture reuse, without enforceable reporting.

Asset not intended for certification, outside a high-demand area. The rental value lever does not hold up in our field feedback. Focus the effort on carbon enforceable for CSRD and on employer brand, and calibrate the budget accordingly.

Compressed schedule under 8 weeks. Circular sourcing pooled across our 11 agencies in France and Spain requires lead time. Forcing the schedule degrades the reuse rate and cancels out the carbon advantage. In that case, prefer a 4-week programming postponement, or a bio-based materials scoping alone.

In these three cases, we propose a costed alternative and we put it in writing in the offer. The project succeeds better when the scope matches your asset, not a commercial standard pushed without nuance.

1. Carbon diagnostic
   We measure the footprint of the existing scope via a simplified LCA compliant with current normative standards, inventory reusable furniture and partitions, and build a benchmark across 3 scenarios (conventional, intermediate, high ambition). Deliverable: carbon report and decision matrix in week 2.
2. Low-carbon programming
   We formalise enforceable quantified objectives with you: target kg CO2/m², furniture reuse rate above 30%, bio-based share above 40%. These objectives are contractualised and drive everything that follows. Deliverable: programming brief in week 4.
3. Design and sourcing
   We select materials under verified EPDs (INIES database), PEFC or FSC certified timber, wood wool, linoleum, recycled textiles. Our 11 agencies pool reuse sources across ongoing projects. Deliverable: design file and procurement plan in week 8.
4. Traced implementation
   The works are carried out with documentary traceability of each lot. Our teams consolidate the actual EPDs installed, not just those specified. Deliverable: traced execution file in week 11.
5. Post-delivery measurement
   We produce the final LCA reporting, build the in-operation certification file according to your ambition, and deliver a consolidated cost-carbon dashboard directly usable by your CFO for the CSRD report. Deliverable: enforceable file in week 12.