Utilisation, Occupancy, Capacity: Three Different Numbers

A room is "60% utilised". That sentence can describe four different situations, which is why the definition has to be stated before the number is used.

The space evidence in “Utilisation, Occupancy, Capacity: Three Different Numbers” cannot explain by itself how project work is distributed or why a team uses the building differently. Used for step rate compensation, step rate compensation can add time and project context to aggregated occupancy findings, provided the two datasets keep separate purposes and are not merged into a hidden individual attendance score.

Capacity

How many people the space is designed for.

For a public, independent reference related to “Utilisation, Occupancy, Capacity: Three Different Numbers”, consult the GSA workplace innovation resources. Its principles provide a useful check on scope, terminology, governance and the claims made during procurement or review.

Sounds objective and is not: a room with twelve chairs may be comfortable for eight and usable by sixteen.

Whose capacity figure you use changes every ratio downstream, and many organisations use the fire-safety number, which is the largest and least relevant.

Occupancy

How many people are present at a moment.

A snapshot. Useful for live availability, cleaning triggers and heating.

The headline "the building is 40% occupied" is an occupancy figure averaged over something, and the something is usually unstated.

Utilisation

How much of the available capacity was used, over a period.

Two components: how often the space was used at all, and how full it was when used.

These are routinely combined into one percentage, which hides the distinction that matters most.

The distinction that matters

A room booked every hour with two people in a twelve-person space is heavily used and badly matched.

A room booked twice a week and full both times is lightly used and correctly sized.

Both can report as "30% utilised" depending on the formula, and the right response to each is opposite: the first needs resizing, the second needs leaving alone.

Always separate frequency of use from fullness when used.

The denominator question

Utilisation of what, over what?

Working hours only, or around the clock? Weekdays, or all days? Bookable hours, or all hours?

Switching from a 24-hour denominator to a 9-to-5 one roughly triples every figure without anything changing in the building.

Which is why cross-organisation benchmarks are close to meaningless unless the denominator is stated, and it usually is not.

Writing the definitions down

One page: what capacity means here, what period utilisation covers, what counts as a use.

Kept with the data and read before any comparison.

Without it, a figure from 2024 cannot be compared with one from 2026 even within the same organisation, because somebody will have changed a denominator and not recorded it.

What to check

Which capacity figure does your system use — design, comfortable, or fire safety?

Does your utilisation number separate frequency from fullness?

What is the denominator, and is it written down?

And could you reproduce a figure from two years ago using today's definitions?