“I need a rock clause.”

I got that request earlier this month. I think you need a rock clause too. Here’s why.

The name ”rock clause” comes from a common construction problem – rock where no one expected rock. If you do much excavation, you understand the problem: a ledge of rock or hard pan, or boulders, or a high water table, or unstable soil. All can increase your costs.

But a rock clause can cover more than excavation. It sets up recovery for site conditions not anticipated by the owner and the contractor. A rock clause is protection from any type of unforeseen site condition. And it makes good sense — a benefit to both the contractor and the owner. You can bid jobs based on what’s known and expected, not on the worst possible contingency. If site conditions are different from what was expected, you get paid for work actually done. The owner gets more competitive bids with smaller contingency allowances.

Here’s a typical rock clause (from Construction Contract Writer):

Contractor shall promptly, and before the conditions are disturbed, give a written notice to owners on encountering unforeseeable conditions adversely affecting the work. Owners shall investigate the site conditions promptly after receiving notice. If the conditions cause an increase in cost to contractor or the time required for performing any part of the work and were not reasonably foreseeable by an experienced contractor, an equitable adjustment shall be made under this clause and the contract modified in writing accordingly.

This clause is essentially the same as Federal Acquisition Regulation § 52.236-2, used routinely on federal construction projects.

Courts in some states recognize two types of unforeseen site conditions. Type I is any hidden condition materially different from what the contractor is entitled to rely on. Type II is a hidden physical condition consistent with the contract documents but very different from anything normally encountered. For example, in an excavation contract, Type II differing site conditions may exist if the rock is much more extensive and much denser than expected.

Both Type I and II conditions are harder to substantiate if:

(1) The owner offers no information about site conditions or disclaims the accuracy of any information offered; and

(2) The contractor doesn’t visit the site or doesn’t investigate all information available; and,

(3) A reasonably prudent contractor would have anticipated the conditions actually found; and

(4) The contract specifically makes the contractor responsible for unexpected site conditions.

In home improvement work, “unexpected site conditions” cover far more than excavation. Nearly any surprise found on site can be covered by a rock clause: wiring or venting where not expected, substandard framing, foundation, plumbing or electrical work — anything unanticipated that’s found after construction begins.

Collecting under a rock clause is always a matter of proof (and negotiation): Would a reasonably experienced contractor have expected a problem like this? Still, you’ve got a leg up and more leverage if your contracts include a rock clause. For better protection against the unexpected, have a look at Construction Contract Writer. The trial version is free.