Addendum
A formal, written change to the bid documents issued by the agency before bids are due - a new drawing, a clarification, a deadline change. Every addendum must be acknowledged in your bid; missing one can make a bid non-responsive.
Estimating Glossary
Common bidding and estimating terms that show up in bid documents and contracts - separate from the CSI scope tag glossary, which explains what a project's tagged scope means rather than the paperwork around it.
Alternate
An optional scope of work priced separately from the base bid - the owner decides after bid opening whether to include it, based on budget. A project might ask for a base bid plus 2-3 priced alternates.
Allowance
A dollar amount built into the contract for work that isn't fully defined yet (a fixture allowance, a rock-excavation allowance) - trued up to actual cost once the real scope is known.
RFI (Request for Information)
A formal question submitted to the design team when the drawings/specs are unclear or conflicting - the answer can change scope, so RFI logs matter for tracking what was actually agreed to.
Change Order
A formal, signed modification to the contract price and/or schedule after award - the mechanism for getting paid for anything beyond the original signed scope.
Retainage
A percentage of each payment (often 5-10%) withheld by the owner until the work is substantially complete, as an incentive to finish and fix punch-list items.
Bid Bond
A bond guaranteeing that if you're awarded the contract, you'll actually sign it and provide the required performance/payment bonds - protects the owner if a low bidder tries to walk away.
Performance Bond / Payment Bond
Bonds provided at contract signing (not bidding): a performance bond guarantees the work gets finished if the contractor defaults; a payment bond guarantees subs/suppliers get paid even if the prime contractor doesn't pay them directly.
General Conditions
The non-physical costs of running a job - supervision, temporary facilities, safety, cleanup - priced separately from the actual construction scope, usually as a percentage or lump sum.
Liquidated Damages
A pre-agreed dollar amount charged per day the project runs late past the contract completion date - agreed to up front specifically so the owner doesn't have to prove actual damages later.
Shop Drawing / Submittal
Detailed fabrication drawings a fabricator prepares and submits for the engineer of record's approval before fabrication starts - distinct from the architect/engineer's own design drawings.
Unit Price vs. Lump Sum
A lump-sum bid is one fixed price for the defined scope; a unit-price bid prices per unit (per ton of steel, per linear foot, per cubic yard) with final payment based on actual measured quantities - common on DOT/highway work where exact quantities aren't known until construction.
Tonnage
The standard pricing/measurement unit for structural steel work - fabricators and erectors often quote per-ton pricing (material + labor) rather than a flat lump sum, especially in early budget conversations.