Kytom integrates the tertiary eco-energy trajectory right from the programming phase of the fit-out project, rather than at the end of the chain. Our teams cross-reference the building's energy audit, the target occupancy scenario (density, hours, remote working) and the technical levers (controlled LED lighting, BMS, free cooling, pipe insulation). On 850 m² on average, we identify 18 to 32% of savings potential that can be activated without structural work. The regulatory declaration is prepared with the landlord, the reference year is justified, and each action is costed in CAPEX, OPEX, and kWhFE/m²/year gain. Since 2006, more than 1200 clients have been supported on this type of real estate decision-making.