Rock at Six Feet: Differing Site Conditions and Late Written Notice
A $9.2 million elementary school is under construction on a site where the geotechnical report showed bedrock at 10–12 ft below grade. While excavating an interior footing, the contractor encounters weathered rock at 6 ft. The superintendent gives verbal notice to the architect on Day 3 and written notice on Day 12. The contract requires written notice within 7 days of the condition. The contractor submits a change order for $148,000 and 18 calendar days, claiming the rock was not foreseeable and that the footing crew was delayed. The owner wants to deny the change order solely because the written notice was late and direct the contractor to “keep moving.” The architect has daily reports, photographs, and the excavation subcontractor’s equipment log.
1. Is the contractor entitled to a change order? Analyze the differing-site-condition claim and the effect of the late written notice.
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The condition is likely a differing site condition: rock at 6 ft is materially different from the geotechnical report’s 10–12 ft, and the contractor could not reasonably have anticipated it from the contract documents. The late written notice is a contract-compliance issue, but it does not automatically destroy entitlement. The architect should determine whether the owner was prejudiced-for example, whether the owner lost the chance to inspect, mitigate, or direct a different solution. Verbal notice on Day 3 gave early knowledge; written notice on Day 12 is five days late. The architect should request the contractor’s actual cost records, the geotechnical interpretation, and the daily reports, then recommend entitlement for the differing condition while reserving the owner’s rights on notice. Denying solely on the technicality invites a claim and may be inconsistent with the architect’s duty to evaluate fairly.
2. How should the architect evaluate the 18-day time request?
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The architect should not accept the 18 days as a lump sum. The contractor must show that rock removal affected the critical path, not merely the footing crew. The architect should request a CPM fragnet or a time-impact analysis showing the excavation activity’s original duration, the actual rock removal duration, and the effect on project completion. If the footing crew was delayed but had float, there may be no time extension. If the rock removal delayed subsequent foundations and steel erection on the critical path, the extension may be valid in whole or part. The equipment log and daily reports can establish actual duration. The architect should also check whether the contractor mitigated by working other areas. The recommendation should tie days to the schedule analysis and should separate owner-caused delay from contractor-caused inefficiency.
3. The owner directs the contractor to proceed and says it will “settle later.” What should the architect advise?
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The architect should advise that a verbal direction to proceed on disputed work creates a constructive-change risk. If the owner wants the work to continue, the architect should recommend a written directive that reserves the owner’s rights on cost and time, requires the contractor to keep daily records, and states that the work is proceeding under protest or pending resolution. The architect should not certify payment for the disputed amount without a change order or owner approval. The architect should also remind the owner that delaying the work to resolve notice could itself cause delay. A practical path is a temporary authorization with a not-to-exceed amount, separate cost codes, and a deadline for the formal determination. The architect’s role is to document the decision, not to become the owner’s advocate for denying a valid claim.