Construction bid documents explained
A bid package is more than drawings. Instructions to bidders, bid forms, alternates, addenda, bond requirements and contract terms decide what you must submit and what you agree to. Estimators who read them first avoid disqualified bids and unpleasant contracts. Here's what's in a package, the deadlines and bond rules that commonly apply, and a pre-submission checklist.
- Instructions to bidders
- Deadlines and addenda
- Bonds
- Submission checklist
What's in a bid package
- Invitation or advertisement: project, owner, due date and location.
- Instructions to bidders: submission rules (AIA A701 is a common form).
- Bid form: base bid, alternates, unit prices and addenda acknowledgments.
- Drawings and specifications, including the front end (Divisions 00 and 01).
- Addenda issued during bidding.
- Contract form and conditions: general and supplementary.
- Bond and insurance requirements.
Read them first
Instructions to bidders tell you how, when and where to submit; how questions and RFIs are handled and by what deadline; whether substitutions are allowed; what must accompany the bid (bond, forms, subcontractor lists); how bids are evaluated; and how long the bid must remain valid. A great price on the wrong form, or one day late, is not a bid.
Questions and addenda
Under AIA A701-2018 Instructions to Bidders, unless the bidding documents say otherwise, bidders' questions are due at least 7 days before the bid date, and addenda are issued no later than 4 days before it (except an addendum that withdraws the request for bids or postpones the date). Bidders acknowledge every addendum on the bid form. Public owners often set their own deadlines, so read the instructions for this project.
Last day for questions (7 days): Thursday, March 19
Last addendum (4 days): Sunday, March 22 (check for addenda through the weekend)
Plan: finish the first-pass takeoff by March 17 so your questions make the deadline
What owners require
- Bid security: a bid bond or other guarantee that you'll sign the contract if awarded. Private owners commonly ask for a percentage of the bid. On federal work, FAR 28.101-2 sets the bid guarantee at at least 20% of the bid price, up to $3 million, when performance and payment bonds are required.
- Performance and payment bonds: on federal construction contracts over $150,000, the Bonds statute (formerly the Miller Act, 40 U.S.C. 3131) requires both, generally at 100% of the original contract price. Between $35,000 and $150,000, the contracting officer selects alternative payment protections.
- State and local work has its own "Little Miller Act" thresholds. Check the project's instructions.
Bond premiums are a real cost. Get your surety's rate before bid day and carry it where the bid form expects it.
Base bid and alternates
The base bid is the price for the work as described in the documents without alternates. Alternates are priced options the owner may accept or reject, as adds or deducts. Unit prices price quantities likely to change. Fill every requested line; blank alternates can make a bid non-responsive.
| Term | Meaning |
|---|---|
| Base bid | Price for the defined scope |
| Add alternate | Extra price for added scope |
| Deduct alternate | Credit for removed or changed scope |
| Unit price | Price per unit for variable quantities |
| Allowance | A set amount carried for undefined items |
What subs should check
- Scope and flow-down clauses that tie you to the prime contract.
- Payment terms, retainage, and pay-when-paid or pay-if-paid language (enforceability varies by state).
- Schedule, liquidated damages and delay provisions.
- Change order procedures and notice deadlines.
- Indemnity and insurance requirements.
This isn't legal advice. Have contract terms reviewed by someone qualified. The estimator's job is to flag terms that affect price and risk.
How to work through a bid package
Division 01 is easy to skip and often expensive. It can require submittals, mockups, temporary protection, cleaning, closeout documents, warranties and coordination meetings, all of which cost money and should be priced or qualified.
- Instructions to bidders and the bid form: due date, delivery method, required forms, alternates and unit prices.
- Addenda: read all of them before measuring, and note which sheets they replace.
- Specification sections in your scope, including Division 01 general requirements.
- Drawings: index, general notes, then your trade's sheets and the related trades' sheets.
- Contract form and supplementary conditions: insurance, bonds, retainage, payment terms and indemnity.
When the package is incomplete
If a referenced sheet or spec section is missing, ask for it through the RFI process before the question deadline. Do not assume the missing document matches the rest. Note any unanswered questions in your qualifications.
Before you submit
- Every addendum acknowledged on the bid form.
- Alternates and unit prices filled in exactly as listed, including "no change" where required.
- Required forms signed and notarized if requested.
- Bid bond or security in the required form and amount.
- Delivery method, location and time confirmed; electronic portals tested a day early.
- Proposal qualifications consistent with the bid form; some owners reject qualified bids, so read the instructions on exceptions.
Quantities and missing information
RenderDraw's AI takeoff extracts scope, quantities, constraints and missing information from bid documents, with the source sheet on every row for estimator review. Bid strategy, contract review and submission stay with your team. Get a free sample takeoff.
Questions estimators ask.
What are construction bid documents?
The invitation, instructions to bidders, bid form, drawings and specs, addenda, contract terms, and bond and insurance requirements.
When are bid questions due?
Per the bid documents. Under AIA A701-2018, unless modified, questions are due at least 7 days before the bid date and addenda are issued no later than 4 days before.
How much is a bid bond?
It varies by owner. On federal work requiring performance and payment bonds, FAR requires a bid guarantee of at least 20% of the bid price, up to $3 million.
When are performance and payment bonds required?
On federal construction contracts over $150,000, generally at 100% of the contract price. State and local thresholds vary.
What is a base bid?
The price for the defined scope without alternates.
What should subs check in bid contracts?
Flow-down, payment and retainage, pay-if-paid language, schedule and liquidated damages, change procedures, indemnity and insurance.
Scope and quantities, reviewed.
RenderDraw's AI takeoff pulls scope, quantities and missing information from the bid package for estimator review. Book a demo.
- Upload the plans, specs and schedules, plus an addendum if you have one.
- RenderDraw reviews the set and the scope you want tested.
- We follow up with extracted quantities, flagged items and next steps.
Where these numbers come from
We checked this guide against the standards, manufacturer documents and industry references below (last reviewed November 2026). Figures marked as rules of thumb are typical ranges, not requirements; your project documents, local code and your own cost history govern.
- Instructions for AIA A701-2018, Instructions to Bidders (AIA Contract Documents)
- FAR Subpart 28.1, Bonds and Other Financial Protections — 20% bid guarantee, $3M cap; bonds over $150,000