Park Change Order, Delay, and Unsafe Utility Excavation
A park renovation contract is valued at $1.85 million with 180 calendar days and liquidated damages of $1,500 per day. At day 60, the contractor reports 20% complete. The owner then directs a 300 m² permeable paver plaza after submittals. The contractor submits a change order for $96,000 and 21 days. Contract unit rates are $180/m² for permeable pavers installed, $35/m² for base aggregate, and $6/m² for geotextile. The schedule shows 12 days of float on the plaza predecessor. Paver lead time is 42 days and installation is 6 days. Separately, a 1.8 m-deep utility excavation near the playground has no protective system, no daily inspection log, and a spoil pile within 1 m of the edge. The owner wants to avoid delay and asks you to approve the change order quickly.
1. Calculate a reasonable direct cost for the change and evaluate the $96,000 proposal.
Read the worked answer
Direct cost: pavers 300 x $180 = $54,000; base 300 x $35 = $10,500; geotextile 300 x $6 = $1,800; subtotal = $66,300. Add 10% overhead and profit = $6,630, giving $72,930 before tax and any removals. The $96,000 proposal is $23,070, or about 32%, above that total, so it needs a detailed breakdown. Allow added costs only if documented: demolition, edge restraint, drainage connections, testing, permits, or winter conditions. Do not approve a lump sum. Request a quantity takeoff, unit rates, and subcontractor quotes. If the owner directed the change after submittals, the contractor is entitled to reasonable cost plus overhead and profit, not a windfall.
2. How many days of time extension, if any, should be approved? Explain the schedule logic.
Read the worked answer
Time extension depends on the critical path. New work duration = 42 days lead time + 6 days installation = 48 days. The predecessor has 12 days of float, so the delay to completion is 48 - 12 = 36 days, assuming no concurrent delay and that the work becomes critical after float is consumed. The contractor requested 21 days, which is less than the calculated 36 and could be accepted if the updated schedule confirms 21 days is the actual critical delay; do not approve by negotiation alone. Require a fragnet and updated CPM. If the contractor can early-order pavers or work concurrently, entitlement may be less. Owner-caused delay should not trigger liquidated damages for that period; document notice and avoid directing acceleration without a cost agreement.
3. What immediate safety and regulatory actions are required at the utility excavation?
Read the worked answer
Stop work in that area until it is controlled. The 1.8 m excavation is a hazard: no protective system, no daily inspection log, and spoil near the edge. Require a competent person to inspect and classify the soil, then install sloping, benching, or shoring for the full depth. Provide safe access within 7.5 m, barricade the excavation, and keep spoils and equipment back from the edge. Verify utility locates and underground lines, control water, and test for hazardous atmosphere if the excavation meets confined-space criteria. Notify the safety officer and document the correction. Resume only after the protective system is in place and inspected. Do not let the owner's schedule pressure override the stop-work decision; if a permit is required, obtain it before work resumes.