Post-Occupancy Evaluation: measuring the real effectiveness of your workspaces

A structured POE builds its measurement around 3 interdependent dimensions, each supported by specific metrics.

• Real spatial effectiveness: occupancy rate per zone (target 60 to 75% in flex office, an operational benchmark commonly observed on our projects), observed versus theoretical circulation flows, spontaneous misuses (meeting room used for solo focus work, phone box turned into storage).
• Behavioural impacts: adoption of new ways of working measured by job profile, user satisfaction by space typology, unanticipated resistance (rejection of flex, attachment to an assigned desk).
• Energy performance in use: actual consumption versus design thermal simulations, over-use of AHUs, deviations from regulatory targets for reducing consumption in the tertiary building stock.

Typological segmentation distinguishes sales/collaboration zones (dynamic clusters, sound level tolerated up to 55 dB(A)) from engineering/concentration zones (workstations with acoustic partitions, a configuration to monitor since a surface area per person below 7 m²/person characterises an unfavourable situation in open space). The central trade-off balances immediate corrective measures (furniture, signage, light partitioning) against behavioural adjustments (training, usage charter). This tension between adapting the space and supporting people determines the final ROI.

When POE is not justified. Below 800 m² or 60 workstations, the cost of IoT instrumentation and analysis relative to the number of corrective measures identified rarely exceeds the value of the gains achieved: a short 3-week qualitative audit is sufficient. Likewise, for a workspace delivered less than 6 months ago, POE is premature because routines have not stabilised; for a workspace older than 36 months with no organisational change, the measured gaps relate more to wear and tear than to design.

4 methodological mistakes that invalidate a tertiary POE

Experience accumulated over several years of POE highlights 4 pitfalls that undermine the reliability of conclusions:

1. Evaluating too early: limiting measurement to the first 3 months, a period when behaviours have not stabilised and novelty biases feedback.
2. Measuring perception alone: capturing subjective satisfaction without cross-referencing it with objective usage data (presence sensors, access badges, Wi-Fi readings) produces an incomplete diagnosis.
3. Ignoring seasonality: overlooking the impact of seasons on outdoor spaces, air conditioning and natural lighting distorts the energy reading.
4. Forgetting transition spaces: circulation areas, airlocks and waiting zones, under-dimensioned at the design stage, regularly concentrate the bottlenecks we observe on large floor plates.

Kytom’s position, at odds with common practice. The facility management doxa favours the satisfaction questionnaire as the foundation of POE. Our experience reverses this hierarchy: stated satisfaction and actual occupancy rate frequently diverge, which leads us to treat the questionnaire as a control variable, never as the main variable. Best practice combines 3 families of data: quantitative metrics (occupancy rate, flows, average dB(A)), qualitative feedback (targeted interviews by profile), behavioural observations (shadowing, heat maps). This multi-source approach to evaluating working conditions enables targeted corrective measures rather than costly generalist adjustments.

Explicit limit of triangulation. With a headcount below 30 people, shadowing and heat maps produce statistically unstable results: individual variance overwhelms the collective signal. In this case, Kytom replaces them with 6 to 8 in-depth interviews and badge tracking over 8 weeks, without claiming statistical representativeness.

Kytom POE methodology in 4 stages over 10 to 12 weeks

The POE methodology runs over 10 to 12 weeks, aligned with the 8-14 month post-delivery window.

• Stage 1, baseline data collection (2 weeks): gathering design assumptions, layout plans, thermal simulations and initial usage objectives.
• Stage 2, behavioural measurements (4 weeks): questionnaires segmented by job profile (administrative, engineering, sales, management), ethnographic observations during peak and off-peak hours, 12 to 20 individual interviews depending on total headcount.
• Stage 3, gap analysis (2 to 3 weeks): mapping of over-used and under-used zones, identification of new emerging flows, distinction between quick adjustments (furniture, signage) and structural modifications (acoustic partitioning, lighting).
• Stage 4, optimisation plan (2 weeks): prioritisation of corrective measures by usage impact and required investment, implementation schedule, follow-up metrics at 6 months.

The design and build approach mobilises the same design and delivery teams on the corrective phase, which reduces rework lead times and avoids loss of information between successive contributors.

For the CFO and Asset Manager: budget ratios and investment trade-offs

A business reading of the subject: POE is not a quality audit, it is an asset management tool. For a CFO, it frames the decision to reinvest 80 to 600 EUR/m² in a recent workspace rather than enduring degraded usage trade-offs over 5 to 7 years. For an Asset Manager, it documents the usage performance of the tertiary asset, a metric required in ESG reporting and in the valuation of leased buildings.

The POEs we conduct produce ratios consistent from one operation to the next, useful for framing rework budgets and arbitrating between light corrective measures and structural modifications.