Bid Security and Bonds: Bid Bonds, Performance Bonds, Payment Bonds, Surety, and Penal Sums

How bid bonds, performance bonds, and payment bonds protect the owner, the role of the surety, penal sum amounts, and the architect's advisory responsibilities during the bidding phase.

ARE · Construction & Evaluation

Overview

Construction bonds are three-party agreements between the owner (obligee), the contractor (principal), and a surety company (guarantor). They serve as financial guarantees that the contractor will fulfill specific obligations. Three types appear in virtually every competitive bid scenario: bid bonds, performance bonds, and payment bonds.

A bid bond guarantees the owner that the low bidder will execute the contract if selected. If the winning bidder walks away, the surety pays the owner the difference between that bid and the next lowest bid, up to the bond's penal sum (typically 5-10% of the bid amount). AIA Document A310 is the standard bid bond form.

A performance bond guarantees the owner that the contractor will complete the work according to the contract documents. If the contractor defaults, the surety must either complete the work or compensate the owner up to the penal sum, which is typically 100% of the contract price. AIA Document A312 is the standard performance and payment bond form.

A payment bond guarantees that the contractor will pay subcontractors, suppliers, and laborers. It protects the owner's property from mechanic's liens by giving unpaid parties a claim against the bond instead of the property. On federal projects, the Miller Act requires both performance and payment bonds for contracts over $150,000.

The architect does not select or approve the surety. The architect's role is to advise the owner on bond requirements during bidding and to include the appropriate bond provisions in the bidding documents. Under A201-2017, Article 11, bond requirements are specified in the insurance and bonds exhibit attached to the owner-contractor agreement.

Essential

Understanding construction bonds requires knowing three things about each type: who it protects, what triggers a claim, and what the penal sum covers. Bid Bonds (AIA A310) A bid bond is submitted with the bid. It guarantees the owner that the bidder, if selected as the lowest responsible bidder, will enter into the contract and furnish the required performance and payment bonds. The penal sum is typically 5-10% of the bid amount. If the low bidder refuses to execute the contract, the owner's damages are the difference between that bid and the next lowest conforming bid. The surety's liability is capped at the penal sum of the bid bond. For example, if Bidder A bids $4,000,000 and Bidder B bids $4,350,000, and Bidder A refuses to execute, the owner's claim against the bid bond surety is $350,000, limited by the penal sum.

Professional

An architect is advising a municipal owner on a $28M library expansion. During pre-bid discussions, the owner's attorney asks whether performance and payment bonds should be required. The project is publicly funded, and the state's Little Miller Act mandates both bonds on contracts over $100,000. The architect confirms the bonding requirement in the Instructions to Bidders and specifies AIA A310 (bid bond) and A312 (performance and payment bonds) with penal sums of 100% of the contract amount. Three bids come in. The apparent low bidder submits a bid bond from a surety company the owner's attorney has not encountered before. The owner asks the architect to evaluate the surety. The architect correctly declines, explaining that surety evaluation is outside the scope of architectural services and could create professional liability exposure. The architect advises the owner to have their attorney or insurance advisor verify the surety's listing on the U.S.

TLDR

Bid bond (A310): 5-10% penal sum; guarantees low bidder will execute contract; owner collects difference between low bid and next bid if bidder walks
Performance bond (A312 Part 1): 100% penal sum; guarantees contractor completes work; protects the OWNER
Payment bond (A312 Part 2): 100% penal sum; guarantees contractor pays subs/suppliers; protects SUBCONTRACTORS and prevents mechanic's liens
Miller Act: federal contracts >$150,000 must have performance + payment bonds
Bond cost: if owner adds bonds after contract execution, contractor gets a change order for cost (A201 Section 11.1.2)
Architect's role: advise on bond requirements; do NOT evaluate or approve the surety
Surety vs. insurance: surety expects zero losses and has indemnity rights against the contractor; insurance pools and absorbs risk
Penal sum: maximum amount surety will pay; change orders increasing the contract sum typically increase the penal sum automatically

ELI5

Think of construction bonds like having a cosigner on a loan. When you hire a contractor for a big project, you want a guarantee that they'll actually do the work and pay the people helping them. A surety company acts as that cosigner. There are three types of bonds, and each one protects someone different. The bid bond is like a deposit on a hotel room. When contractors bid on your project, they include a bid bond that says, "If I win and then change my mind, my surety company will pay you for the trouble." The trouble is usually the difference between their price and the next guy's price. If you bid $100 and walk away, and the next bidder is $115, the surety pays the owner $15. The performance bond is like a warranty on the entire construction job.

AREConstruction & Evaluation

Bid Security and Bonds: Bid Bonds, Performance Bonds, Payment Bonds, Surety, and Penal Sums

How bid bonds, performance bonds, and payment bonds protect the owner, the role of the surety, penal sum amounts, and the architect's advisory responsibilities during the bidding phase.

2 min read262 words

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