Short answer
Cost opinion liability can arise when bids come in well over budget and the owner points to your firm’s estimate. Standard contracts generally treat a designer’s cost figure as a professional opinion, not a guarantee. A claim that an opinion was negligently prepared may fall within professional liability coverage, but the policy wording and the contract decide what applies. Read both before you give an owner a number.
Why budget disputes happen even without a design error
The bids come in 25% over budget. The owner cannot proceed. Within a week, someone asks whether the designer should pay for the redesign.
Nobody did anything obviously wrong in many of these cases. Markets move and scope grows. The cost opinion still carried your firm’s name.
Cost opinion liability: opinions, not guarantees
The commentary on the EJCDC engineering services documents, published by NSPE, ACEC and ASCE, notes that design professionals often struggle to predict construction cost. It explains that the agreements limit how much reliance an owner can place on those opinions.
The AIA approaches it differently, and the difference matters. The AIA B503 guide for amending owner-architect agreements notes that the standard owner-architect agreement makes the architect responsible for estimating the cost of the work to stay within the owner’s budget. If the owner hires a separate cost consultant, the agreement needs an amendment to reflect that.
Where cost opinion liability claims come from
Budget claims tend to start in a few familiar places:
- An early number that the owner treated as a promise
- Scope added after the estimate, without an updated estimate
- A contract clause that requires redesign at the designer’s cost if bids exceed a limit
- No written record of when the owner learned costs were rising
How insurance may respond
Professional liability insurance responds to claims of negligent professional services. A claim that a cost opinion was negligently prepared may fall within that coverage. Policies differ on how they treat cost overruns and estimate guarantees, so read your policy and ask your agent.
Redesign you agreed to perform for free is usually a contract obligation, not an insured loss. Your attorney can explain how a construction cost limit clause works in your agreement.
Example: the 25 percent overrun
A small architecture firm gives a public owner an early cost opinion for a community building. The owner later adds scope, and the firm does not update the opinion in writing. The bids come in 25% over budget, and the owner asks the firm to redesign at its own cost.
The firm sends the contract to its attorney and calls its agent. The agent explains how the policy may treat a claim over the estimate and how it may treat a free redesign promise. The firm also finds its emails showing when the owner added scope.
This example is hypothetical. Coverage depends on the policy terms, exclusions and underwriting.
Habits that help
- Call it an opinion in writing, and avoid “guaranteed” or “not to exceed.”
- Update the opinion when scope changes, and send the update in writing.
- Know whether your contract includes a construction cost limit and what it requires if bids come in high.
- Suggest a professional cost estimator when the owner needs more certainty.
None of these habits guarantees an outcome. They reduce ambiguity about what you told the owner and when.
What to check
- Does your contract include a construction cost limit, and what does it require if bids exceed it?
- Does your contract describe cost figures as opinions?
- Does your policy address cost overruns or estimate guarantees?
- Do you have written updates showing when scope or costs changed?
- Has your attorney reviewed budget and redesign language, and has your agent reviewed the insurance side through the Insurance Requirements Check?
Related questions
Can an owner sue over a cost estimate?
Yes, and some do. Whether there is coverage depends on the policy and the facts.
Should I stop giving cost opinions?
Not necessarily. Owners need them. Frame each one clearly and keep records.
Is a free redesign required by contract covered?
Often not. A promise to redesign at your own cost is typically a contract obligation. Ask your agent how your policy reads.