Bid-Day Mistake, Missing Addendum, and Unit-Price Trap
Halstead Construction submits a lump-sum bid of $3,860,000 for a 90,000-square-foot warehouse. Two days before bid opening, the owner issues Addendum 2, which increases exterior metal flashing from 8,000 linear feet to 20,000 linear feet and requires a 10% bid bond. Halstead's estimator acknowledges Addendum 2 in the bid form but prices only 8,000 linear feet at $9 per linear foot. The same bid contains a roofing line of $180,000 that should have been $810,000 because of a transposition error. The engineer's estimate is $4,050,000; the next-lowest bid is $4,120,000. After opening, Halstead discovers both errors and asks to withdraw its bid. The owner refuses and states that it will award to Halstead and pursue the bid bond. The bid documents state that the unit prices in the schedule govern over the lump sum and that addenda are part of the contract.
1. Can Halstead withdraw its bid based on the roofing transposition and the flashing omission?
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Halstead has a possible but difficult unilateral-mistake claim. To withdraw, it must show a material clerical error, clear and convincing evidence of the mistake, prompt notice after discovery, and that the owner would not be unfairly prejudiced. The roofing transposition is the stronger ground: a $630,000 difference in one line item, inconsistent with the engineer's estimate and the next bid, is objective evidence of a clerical error rather than a business risk. Halstead should promptly provide its original estimate sheets, vendor quotes, and internal calculations.
The flashing omission is weaker. Halstead acknowledged Addendum 2, and the addendum plainly changed the quantity. An acknowledged addendum is part of the contract, and a bidder generally bears the risk of failing to price it. Halstead may argue that the unit price of $9 per linear foot will govern and that the quantity will be corrected at award, but that argument helps the owner more than Halstead: it may convert the omission into a $108,000 adjustment rather than a basis for withdrawal.
The bid bond is a separate exposure. If the owner accepts the bid and Halstead refuses to sign, the surety may be liable, although a timely mistake claim can support relief. Halstead should notify the surety immediately and preserve all bid documents.
2. If the owner awards the contract, how should the flashing quantity and the unit price be handled?
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The addendum controls. Addendum 2 increased the flashing quantity to 20,000 linear feet, and the bid form acknowledged it. If the contract includes a unit-price schedule stating that unit prices govern, the owner will likely adjust the lump sum using the $9 unit price for the actual quantity. That means Halstead may receive an increase of 12,000 linear feet times $9, or $108,000, but it cannot simply ignore the added scope.
The lump-sum figure and the unit price may conflict. Halstead should compare the bid form, the schedule of values, and the contract's order-of-precedence clause. If the unit price governs, the adjustment is mechanical. If the lump sum governs and the quantity was merely estimated, Halstead may argue that the 8,000-foot quantity was a estimate and that the actual quantity should be measured. That argument is weaker where the addendum expressly changed the quantity before bid.
Halstead should not proceed with ambiguity. Before signing, it should request a written clarification of the contract quantity, unit price, and adjustment mechanism. If the owner insists on the lower lump sum with no quantity adjustment, Halstead may face a $108,000 margin loss on top of the roofing error. That combined exposure supports a renewed mistake/withdrawal discussion.
3. What are the risks if Halstead's bid is unbalanced, and how should it respond?
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An unbalanced bid can arise from front-loading, loading a line item that may increase in quantity, or underloading a line that may decrease. Here, the flashing line at $9 per linear foot may be scrutinized because the quantity just increased by 150%. If Halstead deliberately underpriced the base flashing and planned to recover through a quantity adjustment, the owner may characterize the bid as materially unbalanced and reject it or require verification.
Halstead should first determine whether the bid is mathematically or materially unbalanced. Mathematical unbalance exists when a bid is based on prices that do not reasonably reflect costs. Material unbalance exists when the imbalance would result in the owner paying more than the lowest responsive bid over the life of the contract. A single low flashing unit price may not be material, but the combination of the roofing transposition and the flashing omission creates a credibility problem.
Halstead should prepare a cost breakdown proving that its unit prices reflect actual cost plus reasonable markup, and it should be prepared to correct the flashing line if the owner permits. It should not submit a revised bid after opening; that would be improper. Instead, it should use the mistake claim, request withdrawal or correction under the bid documents, and preserve its bid bond rights. If the owner awards the contract, Halstead should seek a written unit-price adjustment and avoid performing disputed extra work without a change order.