If you own or manage a building, lift availability is the number every maintenance report leads with — and the one most likely to be misread. It's also the one contractors are happiest to leave vague. Here's what it means, what "good" looks like, and how to hold a contractor to it.
Lift availability is the proportion of time a lift is in service and available to passengers over a given period. Across the agreements we administer, 98% or higher is the common contractual floor, and in a well-maintained modern building we would expect 99% and above. But the target alone is meaningless without two things beside it: the period it is measured over, and who did the measuring.
What lift availability actually means
The same measure scales from a single lift over a month to a whole portfolio over a year — only the scope changes. It's the clearest measure of whether the equipment, and the contractor maintaining it, are keeping the lifts running.
How is lift availability calculated?
The arithmetic is simple — in-service time divided by total time in the period. The argument is never about the arithmetic. It's about the denominator.
Measure a lift against every hour of the year and an overnight fault that nobody witnessed still counts against it. Measure it only against the building's operating hours and the same fault disappears entirely. Both conventions are defensible, and they produce materially different numbers from identical equipment. What is not defensible is leaving the choice unstated — because an unstated denominator is decided later, by whoever is reporting the result.
The same applies to what gets excluded. Planned shutdowns for modernisation are usually carved out, and reasonably so. But the carve-out is a door: if the agreement doesn't say precisely what qualifies as planned, how much notice makes it so, and who approves it, downtime has a way of migrating into the excluded column. Settle the denominator and the exclusions when you write the agreement, not when you first dispute a report.
What counts as good?
Across the agreements we administer, 98% or higher is the usual floor. That sounds close to perfect — but small percentages hide real downtime. Per lift, across a year, measured against all hours:
| Availability | Roughly equals downtime of… |
|---|---|
| 95% | ~18 days a year |
| 98% | ~7 days a year |
| 99% | ~3.5 days a year |
| 99.5% | ~1.8 days a year |
The gap between 98% and 99% is about three and a half days of downtime per lift, per year. Between 95% and 99% it's a fortnight. Which is why the exact target — and how it's measured — matters more than it first appears.
Why the headline number can mislead
- Averages hide outliers. A portfolio at "98%" can still contain one chronically unreliable lift dragging a whole building down.
- Planned vs unplanned. Scheduled downtime for a modernisation is not the same as repeated unplanned breakdowns.
- When it happened. An outage at morning peak in a busy tower matters far more than the same minutes overnight.
Who measured it — and how would you know?
Most availability reporting rests on an assumption worth examining: that the party being measured is also the party doing the measuring. A contractor's monthly report is a statement about their own performance, compiled from their own records of their own attendances.
That is not an accusation of bad faith. It is a structural problem, and it would exist even if every contractor were scrupulous. Downtime that nobody logs is downtime that never happened. A fault cleared by a building manager before anyone raised a call, an outage that began on a Friday evening, a unit returned to service without a record of when it left — none of it necessarily reaches the report that lands on your desk.
Independent monitoring closes the gap by observing the equipment directly rather than reading a summary of it. The discipline that follows is to hold two numbers beside each other: what was declared, and what was independently detected. Where they agree, you have confidence in both. Where they diverge, the divergence is itself the finding — and it is a far more productive conversation to have with a contractor than an argument about a single headline figure.
What drives availability down
- Slow callout response — the lift is down, but help is hours away.
- Recurring faults left unresolved rather than fixed at the root cause.
- Ageing equipment past its reliable service life.
- Missed or rushed preventive maintenance visits.
What availability doesn't tell you
A lift can be available and still be failing the people using it. Availability measures whether the lift is in service. It says nothing about whether the service is any good.
A bank of lifts can report 99.5% availability while tenants queue through the morning peak, because every unit was technically running the entire time. Availability is a reliability measure, not a performance one. How long people wait, whether the lifts can clear the morning arrival, whether the building simply has enough of them — those questions belong to traffic analysis, and they are graded against different benchmarks entirely.
Both numbers matter, and they fail in different directions. A building with poor availability has a maintenance problem. A building with excellent availability and long waits has a design or dispatch problem — and no amount of maintenance will fix it. Reading the first number as though it answered the second is among the more common mistakes in vertical-transport reporting.
How to hold your contractor to it
Good availability isn't luck — it's specified, measured and reviewed:
- Write a target into the agreement — an explicit service floor, set when you run the tender. We call ours a Minimum Service Delivery Threshold; the name matters less than the fact that it is written down.
- Define the denominator with it. A threshold without a stated measurement period is only half a clause. Say whether it runs against all hours or operating hours, and say it in the agreement.
- Pin down the exclusions. What counts as planned, how much notice makes it so, and who approves it — settled in writing, before the first dispute rather than during it.
- Measure it independently — don't rely on the contractor's own report of their own performance.
- Review it monthly — per unit, not just portfolio-wide, so a single failing lift can't hide in the average.
- Agree what a miss triggers. A threshold with nothing attached to it is a statement of hope. A rectification plan, a review, an escalation — something should follow, and both parties should know what.
Common questions
Is 98% availability good? It is the floor we most often see written into agreements rather than a mark of excellence — measured against all hours, roughly seven days of downtime per lift per year. Whether that is acceptable depends on the building: seven days spread across a large bank of lifts in a low-rise office is a nuisance, while the same figure on the only lift serving a residential tower is a serious problem.
Does planned maintenance count against availability? Usually not, and sensibly so — but only if the agreement defines what qualifies as planned. Where the definition is loose, the exclusion tends to widen over time.
Can availability be measured without the contractor's reports? Yes. Monitoring the equipment directly produces an independent record of when each unit was in service, which can then be compared against what was declared.
Seeing it for real
That's what MAPLE Ascent is built to do — it tracks availability across every unit in your portfolio, to the minute, measured against the threshold written into your contract. "Good availability" stops being a claim in a report and becomes something you can see, compare and act on.
Related reading
More from the MAPLE Ascent Insights series.
Lift modernisation vs replacement: how to decide
Modernisation renews selected subsystems; replacement renews the whole lift. The decision usually turns on obsolescence rather than wear. A framework across condition, obsolescence, disruption and capital — and how to place your own building on it.
Read article →
How much energy do lifts and escalators use?
Lift energy consumption explained: running versus standby energy, what each modernisation technology step actually saves, and how ISO 25745 turns it into an energy class and a payback period.
Read article →
What does a lift maintenance contract actually cover?
What a lift maintenance contract actually covers — comprehensive versus basic scope, the exclusions that generate the extras, and the clauses that quietly decide cost and risk. A guide for building owners and asset managers.
Read article →
How to run a lift maintenance tender in Australia
Lift maintenance tenders in Australia — when to tender, what to prepare, how the process runs and the pitfalls to avoid, for building owners and managers.
Read article →
How many lifts does a building need?
Lift traffic analysis explained — waiting time, handling capacity and demand profiles, benchmarked against PCA, CIBSE Guide D and ISO 8100-32.
Read article →