Team Energy efficiency

Commercial energy efficiency: technical management and compliance with the French tertiary decree

Q: What is the ROI of an LED relamping on a commercial floor?

Between 24 and 36 months for an open space occupied at 70%, with an energy saving generally observed of 50 to 70% per light point depending on the configuration. Under 200 m² or at occupancy below 40%, the payback exceeds 5 years: we recommend postponing the operation to a lease renewal in order to pool the operating shutdown costs.

Q: What regulatory obligations to reduce energy consumption apply to a commercial floor?

Tertiary decree no. 2019-771 of 23 July 2019 applies to buildings used for tertiary purposes with a floor area ≥ 1000 m², with mandatory annual reporting via the OPERAT platform to measure energy savings under the tertiary decree and a target of reducing final energy consumption by 50% by 2040 compared with the reference year (ADEME, 2024). Non-compliance exposes you to publication and to a fine of up to 7,500 EUR (article L174-1 CCH). The real risk remains the 15% rental discount on a non-aligned asset.

Q: When should you not undertake an energy investment?

Under 200 m² occupied at less than 40%, LED relamping has a ROI greater than 5 years: we recommend postponing it to the lease renewal. VRV/VRF air conditioning is counterproductive below 500 m², in which case we steer towards inverter splits (additional cost 30 to 40% lower). A BMS is only justified above 1000 m² or where there are several distinct thermal zones.

Q: What deliverables do you provide at acceptance?

A complete DOE within 15 days, Consuel certification issued by an approved inspection body, the general acceptance report, traced NF C 15-100 compliance, and the initial energy declaration for the floors concerned (>1000 m²). The three key indicators (lighting density, HVAC ratio, cost per workstation) are tracked over 12 months and form your contradictory baseline with the landlord.

The 7,500 EUR fine is not your real problem: the 15% rental discount on a non-aligned asset represents 80 to 120 times that amount on an 850 m² floor.

Paris-region commercial floors typically post an electricity bill in the range of 25 to 35 EUR/m² per year, to which a green discount, now documented by real estate observatories, must be added. We handle all technical levers under a single contract: LED lighting, reversible air conditioning, high and low voltage systems, glazed envelope, with Consuel certification and NF C 15-100 inspection systematically provided at delivery. Our combined reading avoids blind trade-offs between lots and holds the average lead time of 12 weeks across the 1200+ projects delivered since 2006.

The tertiary decree sets the framework, we set your asset’s trajectory.

Our offer

From audit to energy declaration: what a Kytom assignment covers

A Kytom assignment covers all technical levers under a single contract: LED lighting, reversible air conditioning, high and low voltage systems, automation and glazed envelope. You deal with a single point of contact, who manages five lots usually handled separately and compresses your overall lead time to 12 weeks for an 850 m² floor. We deliver a complete DOE within 15 days, the Consuel certification issued by an approved inspection body, the general acceptance report and the initial energy declaration for floors larger than 1000 m².

On recently delivered floors, we aim for a controlled post-delivery energy cost, across all utilities, thanks to our technical choices made from the design stage. The ROI of an LED relamping is generally between 24 and 36 months, with significant savings on consumption per light point, confirmed by feedback from our recent projects. Quote within 5 days of the technical visit.

The Kytom method

Prioritisation by decreasing payback, not by energy weight

Four steps aligned with your occupancy:

Audit and sub-metering (4 to 6 weeks): retrieval of the last three readings and installation of a reference electrical sub-meter, a contradictory baseline to measure savings.
Prioritisation of levers by ROI: we rank by decreasing return rather than by weight in the energy balance. LED relamping accounts for less than 20% of total consumption but offers the fastest payback and finances the heavier HVAC actions.
Works on occupied sites (12 weeks): zoning with protective partitions, interventions outside business hours in sensitive areas, daily cleanliness.
Acceptance and compliance: Consuel certification, NF C 15-100 compliance, DOE delivered within 15 days, initial energy declaration for the floors concerned.

Reversing the order of the levers stretches the financing debt and weakens your tenant works budget. This honesty about the scope has been part of our method since 2006.

Your benefits

Measured indicators and a secured trajectory according to the reduction targets set for 2030, 2040 and 2050

Three indicators are tracked over the 12 months following delivery and feed into your annual energy declaration.

Lighting density: 8 to 10 W/m² after LED relamping, versus 18 to 22 W/m² in an older fluorescent installation, with illuminance maintained between 300 and 500 lux and a colour temperature aligned with the NF X 35-103 grid (< 3300 K if illuminance 5300 K above 1000 lx).
HVAC ratio: 100 to 130 W/m² in cooling, control via presence sensors and CO2 sensors triggering at 800 ppm.
Energy cost per workstation: below 350 EUR per workstation per year, across all utilities.

Beyond the direct savings, alignment with the regulatory trajectory protects you against the growing rental discount observed on non-compliant assets, a risk documented by commercial real estate barometers. The stranded asset effect is being confirmed on offices not aligned with the decarbonisation trajectory.

Method

Preliminary energy audit
We retrieve your last three readings and install an electrical sub-meter over 4 to 6 weeks. This contradictory baseline is used to measure post-delivery savings and to arbitrate between levers according to your target payback.
Prioritisation by ROI
We rank levers by decreasing return on investment rather than by energy weight. LED relamping (ROI 24 to 36 months) finances the heavier HVAC actions. You validate the 5-year investment trajectory before launch.
Works on occupied sites
We align the phases with your occupancy: interventions outside business hours, zoning with protective partitions, daily cleanliness. Average lead time of 12 weeks for an 850 m² floor, standard on our commercial projects.
12-month post-delivery monitoring
Sub-metering maintained over 12 months to measure lighting density, HVAC ratio and energy cost per workstation. These indicators feed into your annual energy declaration and form a contradictory baseline with your landlord or asset manager.

Frequently asked questions

What is the ROI of an LED relamping on a commercial floor?

Between 24 and 36 months for an open space occupied at 70%, with an energy saving generally observed of 50 to 70% per light point depending on the configuration. Under 200 m² or at occupancy below 40%, the payback exceeds 5 years: we recommend postponing the operation to a lease renewal in order to pool the operating shutdown costs.

What regulatory obligations to reduce energy consumption apply to a commercial floor?

Tertiary decree no. 2019-771 of 23 July 2019 applies to buildings used for tertiary purposes with a floor area ≥ 1000 m², with mandatory annual reporting via the OPERAT platform to measure energy savings under the tertiary decree and a target of reducing final energy consumption by 50% by 2040 compared with the reference year (ADEME, 2024). Non-compliance exposes you to publication and to a fine of up to 7,500 EUR (article L174-1 CCH). The real risk remains the 15% rental discount on a non-aligned asset.

When should you not undertake an energy investment?

Under 200 m² occupied at less than 40%, LED relamping has a ROI greater than 5 years: we recommend postponing it to the lease renewal. VRV/VRF air conditioning is counterproductive below 500 m², in which case we steer towards inverter splits (additional cost 30 to 40% lower). A BMS is only justified above 1000 m² or where there are several distinct thermal zones.

What deliverables do you provide at acceptance?

A complete DOE within 15 days, Consuel certification issued by an approved inspection body, the general acceptance report, traced NF C 15-100 compliance, and the initial energy declaration for the floors concerned (>1000 m²). The three key indicators (lighting density, HVAC ratio, cost per workstation) are tracked over 12 months and form your contradictory baseline with the landlord.

05 — Inspirations