How to reduce preliminaries cost on a commercial build

The cost of a slow week

Time-related preliminaries — crane hire, scaffolding, site supervision, security, site sheds, insurances — bill whether work is happening or not. They do not care if your concrete pump was late. They do not care if three trades were waiting on the same crane slot.

On a mid-size commercial build, time-related prelims run to $25,000–$40,000 per week. An 8-week programme overrun burns $200,000–$320,000 that produced nothing.

Most of that is not caused by bad weather or ground conditions. It is caused by disorganisation — specifically, by coordination delays that compound week after week until the programme is unrecoverable.

Where the prelims leak actually happens

Crane idle time. The crane is hired by the day or week. Every idle hour because a booking was not confirmed, or because two crews showed up for the same slot, is hired time you will never recover.

Waiting time between trades. The electricians cannot start second fix until the plasterers are signed off. When the plasterer handover is not confirmed and coordinated, the electricians stand idle. Their day rate bills to the project.

Abortive deliveries. A delivery that arrives when the loading bay is occupied, or when the crane is committed elsewhere, either waits at cost or returns at double cost — rescheduling fee plus a second delivery.

Supervisor time on coordination. A site manager spending 3 to 4 hours per day chasing confirmations by phone is a prelims cost. That time is not recoverable, not billable, and not on the programme.

The coordination changes that reduce prelims

Confirm bookings before the week starts, not on the morning. A booking not confirmed by Thursday afternoon for the following week is a risk. If you cannot confirm it, you need to know on Thursday — not at 06:00 Monday.

Give subbies a shared view of the week. A subbie who can see the whole week's programme will self-manage conflicts. "I can see the crane is tied up until 10, I'll start on the west elevation." That is information, not project management.

Record actual arrival and departure. When you know the pump operator arrived at 07:15 instead of 07:00, you can have a productive conversation about what that 15 minutes cost. Without the record, it is guesswork.

Surface clashes before they become delays. The most expensive clashes are the ones nobody saw coming. A crane booking that conflicts with a concrete pump on the same slot does not need to cause a delay — it needs to be resolved in the planning phase.

The commercial case

Reducing prelims cost by 10% on a $300,000/week prelims budget saves $30,000. On a 50-week project, that is $1.5M. The coordination tools that enable it cost a fraction of that.

SiteLive coordinates bookings, confirmations and arrivals on one live board. The cost-of-delay calculator at sitelive.group shows the prelims impact for your site size.