The Impact of Site Possession Case Study: Assumptions on Project Outcomes

Background

This case study examines a road project involving the construction of foundations for lane user guide gantries at 22 locations along a major highway, both northbound and southbound, with Southbound being done on night shifts. The works were Formworks, Reinforcement and concrete placement (FRP) activities delivered under lane closure site possessions.

At tender stage, the subcontractor relied on lane closure schedules and site times provided in the tender documents. These were interpreted to mean site access would run from 8:00pm prestart through to 4:30am hand back. No explicit assumptions or departures regarding possession times were included in the subcontract submission.

The Problem?

Once works commenced, it became clear that the assumed possession times were not achievable in practice.

• Crews would arrive at 8:00pm, but actual possession was consistently delayed until around 10:30pm.

• All works had to cease by 3:30am for road reopening.

• Light tower issues further cut into usable working time.

This meant subcontractors were achieving only 4.5-5 productive hours per shift while paying for 10-hour shifts in labour costs once all was considered. The result was a compounding cost and program impact: margins were under immediate threat, and the delivery program became unachievable under the original conditions.

Objectives

The subcontractor’s primary objectives were to:

• Recover excess labour costs caused by reduced site possession.

• Demonstrate the cause-and-effect relationship between possession delays and program impact.

• Protect the commercial relationship with the client by resolving the issue without escalating to formal dispute.

How did we approach it?

The approach taken focused on converting raw site information into clear, demonstrable evidence.

• Data collection: Daily dockets, site diaries, and photographs were compiled to show consistent delays in possession handover and early hand back.

• Pattern analysis: These records were structured to demonstrate a recurring loss of possession across every shift, not isolated incidents.

• Contract review: Tender lane closure schedules were cross-checked against actual possession to show the disconnect between assumptions and reality.

Findings

Analysis confirmed the scale of the problem:

• Average nightly possession of 4.5-5 hours, versus the tender assumption of 8-9 hours.

• Crews of 4-8 workers were under utilised due to restricted access.

• Labour costs escalated sharply, with over $100,000 in excess man-hours incurred.

• The shortened possession also compounded program delays, proving the delivery schedule was unachievable under actual site conditions.

Analysis

The strength of the claim came from demonstrating cause and effect. Reduced possession was not presented as a subcontractor inefficiency but as a direct variance from tendered information.

By aligning daily records with the tender lane closure schedules, it was possible to prove that the subcontractor’s pricing and program assumptions were reasonable and that actual site conditions caused the overrun. This reframed the discussion from a dispute to a reconciliation of expectations versus reality.

Outcome

Through structured evidence and professional negotiation, the subcontractor successfully recovered over $100,000 in labour charges. The resolution:

• Was achieved without legal escalation or formal dispute.

• Preserved the working relationship with the client.

• Reinforced the subcontractor’s credibility by demonstrating disciplined site management and commercial acumen.

Lessons Learned

This case illustrates risks and opportunities that apply to all construction projects.

1. Always articulate assumptions at tender stage.
   Many disputes don’t come from what’s written, but from what’s assumed. Clearly state in your contract departures what possession times, access arrangements, or work windows your price is based on.

2. Differentiate access from productive time.
   Being on site does not equal working time. Mobilisation, late possession, or early hand back erode productivity. Programs and pricing must reflect usable hours, not just access windows.

3. Good records transform assumptions into evidence.
   Daily diaries, dockets, and photos are essential to turn possession gaps into demonstrable cost impacts. Without them, subcontractors are left carrying the risk.

4. Strong possession drives efficiency.
   The flip side is just as important. When site possession is reliable and well-managed, crews achieve more in a shift, resources can be redeployed effectively, and margins are strengthened. Every additional productive hour increases the return on labour and plant.

5. Clarity reduces disputes and builds trust.
   Explicit assumptions protect subcontractors, but they also give clients confidence that programs are achievable. Projects run smoother, disputes are fewer, and relationships improve when possession is clear from the outset.

Conclusion

Poor site possession nearly cost a six-figure sum in this project. But the lessons go far beyond roads. Across all sectors, civil, building, rail, and infrastructure, your assumptions, access, and records are critical levers that determine profitability and delivery success.

By making assumptions explicit at tender, keeping disciplined site records, and understanding the link between possession and productivity, subcontractors can protect margins, strengthen delivery, and build more collaborative relationships with their clients.

PillarPoint continues to support subcontractors with tender reviews, contract departures, and project record management, ensuring that site possession never becomes the silent factor that makes or breaks a job.