space planning: calibrating density and flexibility to your usage patterns

Kytom structures space planning in measurable phases. Ratios follow observed use and are cross-checked with workplace references and the Kytom Observatory (€/m², CC BY 4.0). Floor acoustics targets draw on NF S31-080 and ISO 3382 orders of magnitude.

Kytom also documents m² trade-offs via the Kytom Observatory (CC BY 4.0), INSEE and ADEME tertiary guidance; floor air quality and acoustics draw on ISO 3382 and NF S31-080 orders of magnitude.

Kytom rejects sizing on declared HR averages alone: peak-hour saturation and over-sized floors cost more than the initial audit.

A high-performing floor plate constantly balances four conflicting dimensions, and that is where usage value is won or lost.

Occupancy density is measured in m²/person: the former standard recommended a minimum of 10 m²/person in individual or shared offices (Source, 2023). Usage flexibility assesses the ability to reconfigure without major works. Circulation flows determine travel times between work zones, meeting rooms and common areas. Acoustic comfort relies in particular on the CERFF standard, which sets a minimum acoustic attenuation of 38 dB for glazed partitions.

Our field observations on tertiary floor plates of over 500 m² bring out three recurring constants: occupancy peaks concentrate at the start and middle of the day, HR self-reports systematically overestimate the actual measured occupancy rate, and a significant share of work interactions takes place outside formal meeting rooms.

In practice at Kytom, average occupancy is never our calibration reference. Common practice consists of sizing to the average rate (often 75%); we model three distinct scenarios (minimum, median, peak occupancy) and calibrate to the 80th percentile. Designing the organization according to the geometry of the building means guaranteeing lasting usage dysfunctions.

Three pitfalls systematically recur on the projects we take over, with a direct impact on occupancy cost and asset value.

1. Starting from the geometry of the building rather than from usage. Floor plates are designed according to column grids and facades, with no correlation to job profiles. The result: enclosed offices along the facade while the functions concerned favor open collaboration. For the Asset Manager, this translates into a floor plate that is difficult to market when tenants change.

2. Undersizing technical networks. Resizing electrical, low-voltage or HVAC networks after delivery costs several times more than anticipating it at the design stage. For the CFO, this is non-amortizable CAPEX and several weeks of avoided rent lost. The regulatory framework applicable to the tertiary stock requires a 40% reduction in consumption by 2030, which reinforces the need for HVAC/electrical anticipation.

3. Neglecting acoustics in open spaces. Beyond 12 to 15 workstations per untreated zone, the sound level exceeds the acceptable acoustic thresholds in open offices, degrading productivity and well-being. The HR impact (absenteeism, turnover) is rarely quantified in the initial business case.

Our response consists of reversing the logic: a behavioral audit of the existing setup, flow modeling by persona, then sizing the infrastructure to absorb a comfortable margin for evolution without disruption.

Since 2006, Kytom has delivered more than 1200 projects whose lessons feed our calibration benchmarks by sector. For the Architect and the Asset Manager, these benchmarks frame the programming assumptions within 2 to 3 days before the instrumented audit.

These ratios come from our sensor measurements and our behavioral audits conducted sector by sector, not from generic copy-pasted standards. A consulting floor plate calibrated on insurance ratios quickly loses efficiency; the reverse generates acoustic saturation and usage conflicts. The right calibration is the one that anticipates the 80th percentile of your sector, not the all-sectors average.

We regularly decline to impose the full approach when the project economics do not justify it. Three typical cases.

Floor plates under 300 m² with a single team. The behavioral-audit-to-geometry reversal is not relevant: the statistical variability of sensor measurements remains too low (n users below 25) to justify the instrumentation cost. We apply our persona benchmarks directly, without an audit phase.

Building intended for resale within 24 months. Oversizing networks to absorb future evolution has no ROI for the Asset Manager: strict calibration is sufficient, and we steer the trade-off toward short-term marketability rather than long-term usage performance.

Projects below 800 m² or with an overall timeline of less than 4 months. The instrumented prototyping step then represents a disproportionate share of the fit-out budget, with no measurable marginal benefit. We apply our persona benchmarks directly.

The Kytom method finds its optimum between 600 and 5000 m² with an occupancy horizon of more than 5 years. Outside this zone, we adapt (and sometimes we recommend a better-positioned peer). This transparency is part of the service we sell.

1. Behavioral audit
   We instrument your current floor plate with occupancy sensors for 2 to 3 weeks, complemented by targeted interviews with managers and users. Deliverable: a mapping of actual usage, identification of peaks, the measured gap between HR self-reports and effective occupancy. This phase grounds all subsequent decisions on verifiable data, not on assumptions.
2. Flow modeling
   Over 2 weeks, we build three occupancy scenarios (baseline, median, peak) and model circulation flows by job persona. We calibrate to the 80th percentile, not to the average. Deliverable: a master plan of zones, target ratios by function, sizing of collaborative spaces (informal and formal) based on measured usage.
3. Integrated technical sizing
   Within 3 to 4 weeks, our design and build team simultaneously validates the spatial intent and the technical feasibility: cable trays, HVAC terminals, floor loads, acoustic treatments compliant with the requirements applicable to office spaces, anticipation of the energy-consumption-reduction obligations applicable to the tertiary sector. Deliverable: a summary of partitions, electrical, HVAC and data with a 20 to 30% margin for evolution.
4. Prototyping and measurement
   Before rollout, we instrument a representative test zone for 2 weeks to adjust density, furniture and acoustic treatments based on post-installation measurements. This iterative loop reduces post-delivery rework by 60 to 80% on floor plates > 1500 m². Deliverable: adjustments validated by proof before full deployment.