Contracts

Addendum

A written modification to bid documents issued before the bid date to clarify drawings or change scope.

A construction addendum is a formal written change to bid documents issued by the architect or owner before the bid submission deadline. Addenda typically clarify ambiguities in the drawings, modify scope, change material specifications, or extend the bid date. They are sequentially numbered (Addendum #1, #2, etc.) and become part of the contract documents on bid submission.

All bidders must acknowledge receipt of every addendum on their bid form. Failure to incorporate an addendum into the bid can disqualify the bidder or expose them to scope they did not price. Bidders should track addenda in their bid log and confirm receipt of each one on their submitted bid.

Frequently asked questions

What is an addendum in construction bidding?+

A formal written change to bid documents issued by the architect or owner before bid submission. Addenda clarify ambiguities, modify scope, change specs, or extend deadlines. They are sequentially numbered and become part of the contract documents.

When are addenda issued?+

Typically during the bidding period, often after pre-bid walkthroughs or RFIs surface questions that affect multiple bidders. Owners commonly close the addendum window 5 to 7 days before bid submission to give bidders time to incorporate changes.

What happens if I miss an addendum?+

You may be disqualified or held to scope you did not price. Always check the bid documents site daily during the bidding period and acknowledge every addendum on your bid form.

Related terms

Bid

A contractor's formal price proposal to perform a defined scope of work, usually in response to a bid invitation.

RFI

A formal written question from a contractor to the design team requesting clarification on drawings or specs.

Scope of Work

The written description of all tasks, materials, and deliverables the contractor agrees to perform on the project.

Contract

The binding written agreement between owner and contractor defining scope, price, schedule, and terms of the project.