KONE CTU Elevators Explained: Construction Time Use Solutions for Builders and Project Managers

A construction time use lift, or builder's lift, changes that sequence.

CTU stands for Construction Time Use. A CTU lift is the building's own permanent lift, fitted with temporary fixtures and protective materials so it can be put to work during the build rather than waiting until the end of it.

That is the whole idea in one line. You are not hiring a temporary machine. You are bringing forward an asset you have already paid for.

On site you will hear it called a builder's lift. Same thing. CTU is the term that turns up in specifications and tender documents, builder's lift is what most people actually say, and both describe putting the building's permanent lift to work during construction rather than relying on an external hoist bolted to the facade.

The best known version is KONE JumpLift, a self-climbing system that runs in the permanent shaft and grows with the building.

CTU meaning in construction comes down to sequencing, so it is worth walking through what actually happens.

Once the shaft can be weatherproofed, permanent components go in at the base. A temporary machine room, sometimes called a cathead, is installed in the shaft, typically once the structure reaches somewhere between the fifth and tenth floor. From that point, the lift starts carrying people and equipment to the floors below it.

Above the lift sits a protection deck. Below it, the lift runs. Above it, your crews keep installing guide rails, entrances and doors on the upper levels. The two activities happen in the same shaft at the same time, separated by the deck.

When the structure reaches the next trigger floor in the jump plan, the machine room climbs. Jumps usually cover three floors at a time, up to about five, and each one can be scheduled around whatever else is happening on site. Moving the machine room does not need a crane, which is the detail most project managers care about, because it means the jump does not have to be negotiated with every other trade competing for lifting capacity that week.

This is the comparison that matters, and it is worth being specific rather than general.

Speed and capacity: A CTU construction lift can run at speeds well beyond a rack-and-pinion hoist, with materially higher load capacity. On a tall building, that difference compounds across every trade, every day, for the length of the programme.

Weather: The hoist is bolted to the outside of your building. The CTU lift is inside it. Wind that shuts down an external hoist does not stop a lift running in an enclosed shaft, and on an exposed Australian site that is a meaningful number of days across a year.

Safety: Workers travel inside a permanent lift car in a permanent shaft, rather than in an external cage exposed to weather and to the risks that come with equipment attached to a facade.

The facade: This is the one that gets underweighted. An external hoist needs tie-ins, and those tie-ins hold open a section of your facade until the hoist comes off. Take the hoist out of the equation, and you can close the building envelope earlier, which pulls forward every internal trade that was waiting on a weathertight building.

Everything above turns into the same currency, which is time.

Less queueing at the base of the building. Fewer weather days lost. Earlier facade closure, and therefore earlier start for internal fitout. Fewer crane movements tied up in relocating hoisting equipment. KONE's own figure for what queueing costs on a tall site is up to an hour of shift time per worker per day, spent waiting for transport to the upper floors. Multiply that across your trades and the number gets uncomfortable quickly.

For the builder, that shows up as programme certainty. For the developer behind you, it shows up as earlier practical completion, earlier occupancy and a shorter run of interest payments on the construction facility. Those are different conversations with different people, and the CTU case is easier to make when you separate them.

Not every project needs one, and pretending otherwise would waste your time.

The case is strongest on tall buildings with a long vertical transport task, where the permanent shaft can be weatherproofed reasonably early, and where the programme is tight enough that vertical logistics sits on the critical path. Residential and hotel towers, large commercial cores, mixed-use developments over roughly fifteen levels.

It is weaker on low-rise work, on projects where the core goes in late, and on buildings where the shaft cannot be enclosed until well into the structure. A hoist is sometimes simply the right answer.

It is also not always either-or. A CTU lift can complement an external hoist rather than replace it outright, taking the people movement while the hoist keeps the bulk materials.

At the end of the structural programme, the lift does not come out. It gets finished.

The permanent machinery goes in, the temporary protective materials come off, and the car surfaces, remaining landing doors, fixtures and signalisation are completed. The shaft, the car sling, the counterweight and the guides have been in place the whole time. Details of that sequence sit on the KONE elevator installation process page.

Compare that to dismantling a hoist, patching the facade, then starting a lift installation from scratch in a shaft that has been empty for two years, and the handover picture looks very different.

The one thing that determines whether a CTU works on your project is when the conversation happens. Shaft design, weatherproofing sequence and the jump plan all need to align with your structural programme, and that is a design-stage discussion rather than a procurement one.

If you have a project in early planning, the detail on KONE Construction Time Use elevators sets out the options and where they fit. Bring us in while the core is still on paper and the answer is usually better than it would be six months later.