Differing Site Conditions Claims: What Contractors Need to Prove

Every contractor has a story about the ground that did not match the plans. You price a job from the soil report and site drawings, break ground, and hit buried debris, groundwater, or solid rock that nobody mentioned. Suddenly the schedule slips and the budget bleeds. A differing site conditions claim is how a contractor asks for added time or money when that happens, but winning one takes proof, not just frustration.

Two Types of Differing Conditions

Most contracts recognize two categories. A Type I condition is a subsurface or hidden physical condition that differs materially from what the contract documents indicated, such as plans showing sandy soil when the crew finds limestone. A Type II condition is an unknown physical condition of an unusual nature that differs materially from what a contractor would ordinarily expect on that kind of work. Type II claims are tougher because there is no document to point to.

Both definitions track the clause required on federal-aid highway projects under 23 C.F.R. § 635.109, and the federal clause at FAR 52.236-2 uses the same language. Plenty of private contract forms borrow it too.

What You Have to Show

Your contract controls the details, but most claims turn on the same building blocks:

• The condition was a real physical condition at the site, not just a delay or a design disagreement.
• It differed materially from the contract documents or from what was reasonably expected.
• You relied on the contract information and performed a reasonable investigation before bidding.
• You gave written notice on time, normally before the area was disturbed.
• The condition caused added cost or delay, and you can document the amount.

Reliance Is Not a Formality

Florida’s Third District Court of Appeal has explained that a differing site conditions clause is triggered by an inaccurate representation that the contractor relied on, not by the absence of any representation. If the owner never said anything about a particular condition and the contractor leaned on its own thin investigation, recovery may be off the table. On the other hand, when bid documents were wrong, a clause telling you to inspect the site does not automatically wipe out your claim.

Notice Is Where Claims Go to Die

Late notice sinks more claims than almost anything else. The federal rule calls for prompt written notice before the site is disturbed, and it bars a contract adjustment that benefits the contractor if that notice was not given. Private contracts often set their own deadlines, sometimes measured in just a few days.

When you hit something unexpected, stop work in that area if it is safe to do so. Take photos and video, note depths and measurements, and send written notice right away. Verbal updates on the jobsite will not carry much weight later.

Prove the Money

Even a valid condition does not guarantee full payment. You need daily logs, equipment and labor records, and a clear link between the condition and your added cost. Keeping those records separate from your general job costs makes your claim far easier to defend.

Hit something the plans never promised? Our Fort Lauderdale construction attorneys at Sweeney Law, P.A. can review your contract language and notice deadlines before they pass. Call us at 954-440-3993 and we will help you decide the best path forward.

Sources:

ecfr.gov/current/title-23/chapter-I/subchapter-G/part-635/subpart-A/section-635.109

acquisition.gov/far/52.236-2