What is Space Utilization vs Occupancy?

Occupancy describes how much space is assigned or filled; utilization describes how much of that space is actually used over time.

Definition

Space utilization and occupancy are related but different measures, and confusing them leads to poor decisions. Occupancy usually describes whether space is assigned or filled: how many desks have an owner, how much of a building is leased or how many people are present at a moment. Utilization describes how intensively that space is used over a period: the share of available hours a desk or room is actually in use.

A building can be 100% occupied in the sense that every desk is assigned to someone, yet only 40% utilized because people are at home, travelling or in meetings much of the time. IBM's TRIRIGA documentation shows the occupancy rate metric, sourced from IFMA, as Space Used ÷ Space Available, where space used means space assigned to an organisation.

Attendance adds a third concept: how many people came to the workplace. Envoy summarises the difference simply: attendance tells you who came; utilization tells you how much of the workplace they used.

Example

An office has 100 desks, all assigned to named employees. Occupancy by assignment is 100%. Badge data shows an average of 55 people entering per day, so attendance is 55% of headcount. Hourly desk counts show that on average only 38 desks are in use at any moment, because people spend time in meetings, at lunch or elsewhere. Average desk utilization is 38%.

If leadership looked only at occupancy, it would conclude the office is full and needs more space. If it looked only at attendance, it would assume 55 desks are busy. Utilization reveals the real level of desk use.

How it relates to an office map

In the Office Map Editor, the Who sits here field shows assignment, while bookings and attendance show who is actually in. Seeing both on the same floor plan makes the gap between occupancy and utilization visible desk by desk.

Side-by-side definitions

Keeping the three concepts separate makes reports easier to read and harder to misinterpret.

Occupancy: space or seats assigned or filled, often as a share of total
Attendance: people who came to the workplace, often as a share of headcount or a baseline
Utilization: share of available capacity actually used over a period
Peak utilization: highest level of use in the period
Average utilization: mean level of use across the period

How attendance indexes fit in

Public numbers quoted in the news are usually attendance indexes. Kastle's Back to Work Barometer, as explained by Van Vlissingen and Co., counts each cardholder's first building entry per day and compares it with February 2020 activity treated as 100%. Its ten-city average for the week ending September 16, 2026 was 56.3%. That figure does not mean 56.3% of desks were filled; it means unique daily entries ran at about 56% of their pre-pandemic level.

Why the difference matters for decisions

Occupancy drives questions about who owns which space. Utilization drives questions about how much space is needed. Using occupancy to size an office leads to too much space in a hybrid world; using average utilization alone leads to too little space on peak days.

CBRE's 2025 European survey illustrates the second risk: a 46% weekly average utilization coexisted with a 71% peak-day average.

Measuring each one

Occupancy is usually measured from lease records, seating charts and HR data. Attendance comes from access control, sign-in systems or booking check-ins. Utilization requires observation, sensors or detailed booking data matched with actual use. A current floor plan with a seating chart supports all three because it defines what space exists and who is assigned to it.

Example: unassigned desks

When desks are unassigned, occupancy in the assignment sense disappears and utilization becomes the main measure. CBRE reported that unassigned desks are now the norm at 61% of the companies in its 2025 European survey. In such offices, a booking system and a live map replace the seating chart as the record of who sits where on a given day.

Communicating the difference

When presenting to leadership, label every number explicitly: occupancy by assignment, attendance versus baseline, average utilization and peak utilization. Show them side by side on one chart. This prevents the most common misunderstanding: treating a headline attendance index as if it described desk use.

Common mistakes

Using the terms interchangeably in reports, comparing one organisation's utilization with another's occupancy, and relying on public attendance indexes to size a specific office are the most frequent errors. Always measure your own utilization before making space decisions.

Worked comparison across a week

Take a team of 40 people with 40 assigned desks. Occupancy by assignment is 100% every day. Over one week, daily attendance is 18 on Monday, 32 on Tuesday, 35 on Wednesday, 28 on Thursday and 12 on Friday. Hourly desk counts show peak desk use of 14, 27, 30, 23 and 10 desks on the same days.

Peak desk utilization therefore ranges from 25% on Friday to 75% on Wednesday, while occupancy stays at 100%. Attendance and utilization differ too: on Wednesday 35 people came in, but no more than 30 desks were used at the same time, because people moved between desks, rooms and other spaces.

This example shows why all three measures are needed. Occupancy says the team owns 40 desks, attendance says how many people visit and utilization says how many desks the team actually needs at once — about 30 on its busiest day.

When occupancy is the right measure

Occupancy remains the right measure for lease administration, emergency planning and chargeback models where teams pay for allocated space. It is also useful for tracking how much of a portfolio is committed versus vacant. Utilization becomes the right measure whenever the question is how much space is needed or how well it is used.

Related concepts explained

Several supporting terms appear whenever occupancy and utilization are discussed. Getting them right makes reports clearer and prevents the most common misreadings of workplace data.

Headcount: the number of people assigned to a site or team
Sharing ratio: headcount divided by desks; above 1.0 means more people than desks
Baseline: the reference period an index is compared with, such as February 2020 for Kastle's Barometer
Peak day: the busiest day in a period, used to size capacity
No-show: a booking that is not used, which inflates apparent demand

Putting it into practice

In your next workplace report, add a small box that defines each measure you use in one line, with its data source and time window. Present occupancy, attendance and utilization side by side for the same period and the same space. Highlight peak-day utilization, because that is what determines whether people can find a seat. Over a few reporting cycles, colleagues will start using the terms precisely, and discussions about whether the office is too big or too small will rest on shared definitions rather than impressions.

A simple way to remember the difference

Think of a car park. Occupancy is how many spaces have a name painted on them or are rented out. Attendance is how many cars entered today. Utilization is how many spaces actually had a car in them, and for how long, across the day. All three numbers are useful, but they answer different questions and can tell very different stories about the same car park.

Offices work the same way. Assigned desks, building entries and actual desk use are three separate facts. Mixing them up is the root of many disagreements about whether an office is too big or too small.

Using both measures together

Occupancy is still useful in a hybrid world. It tells you how much space is committed to teams, which matters for neighbourhood planning and chargebacks. Utilization tells you whether that commitment is justified by actual use. Reviewing both by team reveals where assigned space is barely used and could be shared, and where teams use more than they are allocated.

Key takeaways

Keep these distinctions clear in every report.

Occupancy: assigned or filled space
Attendance: people who came in
Utilization: capacity actually used over time
Headline attendance indexes are not desk utilization
Size space with peak utilization, not occupancy
Label every number explicitly

Frequently asked questions

Can occupancy be higher than utilization? Yes, and in hybrid offices it usually is: desks can be assigned to people who are often not present.

Can utilization exceed 100%? Not for a single space in a single moment, but sharing ratios above one person per desk mean more people are assigned than seats exist, which is normal in hybrid offices.

Which should I report to leadership? Both, side by side, with peak and average utilization, so decisions are based on the full picture.

Summary

Occupancy tells you what space is assigned, attendance tells you who came in and utilization tells you how much capacity was actually used. In hybrid offices these numbers diverge sharply, so treat them as separate measures and label them clearly in every report. Size space using peak utilization measured in your own office, not headline attendance indexes, and use occupancy for allocation, emergency planning and chargebacks.