The first risks a contractor takes on are the ones baked into the bid — long before a shovel touches dirt.

Every construction project carries risk, but few phases concentrate it as sharply as the bid. The estimate a contractor submits is a promise made under uncertainty: about quantities that may shift, about ground no one has fully seen, and about subcontractors whose performance is still hypothetical. Once the bid is accepted, most of those assumptions harden into obligations. Understanding where bidding risk lives — and how to price or transfer it — is the difference between a profitable job and a money-loser that looks fine on paper.

Subsurface conditions are among the largest single risks in heavy-civil and transportation work, where excavation, foundations, and tunneling dominate scope. The default legal rule has historically been unforgiving: on a fixed-price job, absent a contractual mechanism, the contractor bears the cost of unforeseen or unusual subsurface conditions. That default is exactly why the differing site conditions clause matters so much.

A standard DSC clause recognizes two categories. Type 1 conditions are those that differ materially from what the contract documents indicated. Type 2 conditions are unknown or unusual and differ materially from what a reasonable bidder would ordinarily expect. Where a DSC clause is present, it converts a hidden risk into a defined, compensable event — provided the contractor documents the condition and gives timely notice.

When bidding, contractors should confirm whether a DSC clause exists, review all geotechnical data the owner has made available, and be wary of exculpatory language that attempts to disclaim the reliability of that data. Where owners permit supplementary subsurface investigation before bid, taking advantage of it can be far cheaper than litigating a condition later.

A general contractor's bid is only as sound as the subcontractor pricing beneath it. A single quote on a major trade package is, in effect, an assumption dressed up as a number. On higher-risk projects, prudent contractors solicit multiple leveled bids for critical trades before committing, so that the sub price in the bid reflects a tested market rather than a hopeful guess.

Subcontractor risk extends beyond price. Availability, financial stability, and capacity all bear on whether a sub can actually deliver — particularly in a market strained by mega-projects and large backlogs. Vetting subcontractors, confirming their bonding and insurance, and building default remedies into subcontracts are all ways of managing exposure that would otherwise land on the prime when a key sub fails to perform.

Unit-price and quantity-based contracts assign contractors the job of pricing work whose true scope is not yet fixed. When actual quantities diverge materially from the estimates in the bid documents, the economics of the job can change overnight. Variation-in-quantity clauses exist to reallocate that risk equitably, adjusting compensation when increases or decreases result from conditions not reasonably apparent when the parties signed. Federal contracts address the same problem through changes-and-changed-conditions provisions requiring notice when quantities or conditions differ materially from what the contract indicated.

The practical lesson for contractors is twofold. First, read the quantity assumptions in the solicitation critically rather than accepting them at face value. Second, understand the mechanism the contract provides for adjustment — and the notice obligations that come with it. A right to a quantity adjustment is worth little if the contractor fails to flag the variance in time.

Bid risk is the aggregate of everything that could make a project cost more, take longer, or generate disputes beyond what was anticipated at submission. The contractors who manage it best treat the estimate not as a sales document but as a risk allocation exercise — scoring owner payment history, contract terms, design completeness, and subcontractor coverage before deciding whether, and at what price, to pursue the work.

Next issue: Project Management Risks