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How One Estimator Reads a Sub Bid for What It Leaves Out | ConstructionMagazine.ai
How One Estimator Reads a Sub Bid for What It Leaves Out
A chatbot caught a missing pizza-oven hood in a subcontractor proposal. The tool that grew out of that afternoon marks every scope item present, missing, or ambiguous, and treats ambiguous as an answer.
An estimator at one of the GCs we talked to pasted a subcontractor's bid next to the plans and asked a chatbot whether everything was included. It came back with a missing hood for a pizza oven. The risk in a subcontractor proposal is rarely a wrong price on a known item. It is an exclusion that never appears as a sentence.
The tool the firm built after that afternoon marks every scope item Present, Missing, or Ambiguous. Ambiguous is a full answer with the same weight as the other two. A reviewer forced to a yes or a no is the reviewer who misses the gap. The checklist behind those marks has to be the firm's own: what dark shell includes on this job, what the base building covers, what the owner supplies. Commercial real estate glossaries disagree on what dark shell and warm shell mean, so a model left to supply the definitions supplies someone else's.
Every scope row lands in one of three trays. AI-assisted illustration.
Where an exclusion hides on the page
A subcontractor proposal has a shape, and the shape is where the trouble sits. The first page carries a price and a scope paragraph written to sound complete. The next page carries inclusions, then exclusions, then a block usually headed clarifications or qualifications. The exclusions are the honest part. The clarifications are where a hood becomes somebody else's problem: a line that says the price assumes owner-furnished equipment, or that ductwork stops at the roof penetration, or that the quote is based on the drawings dated a month before the current set. None of those sentences says the hood is out. Each of them means it.
The desk's checklist is written against that shape. Every item on the firm's scope template for the trade appears as a row, and the reviewer reads the proposal for each row three times: once in the scope paragraph, once in the inclusions and exclusions, and once in the clarifications. A row is Present when the proposal names it or clearly covers it. It is Missing when the proposal excludes it or is silent where the template expects a sentence. It is Ambiguous when a clarification could be read either way. The pizza-oven hood was Ambiguous. The kitchen equipment was owner-furnished, the hood was not, and the proposal did not say which side of that line it stood on.
Fifteen trades, five quotes, and the gaps between them
A typical commercial job carries fifteen to twenty trades, and a general contractor collects three to five quotes for each package. That is up to a hundred quotes on one bid, each written by a firm with its own habits about what to leave out. Scaffolding is in one and out of the next. Temporary power belongs to the electrician in one bid and to nobody in another. At that volume, gaps are not a risk to be managed down to zero. They are a certainty to be found.
Finding them is only the first column of the sheet. A missing item has to become a number so the quotes can be compared. Leveling means pricing an adjustment for every inclusion and exclusion until each sub is bidding the same scope on paper, and then setting a risk note beside each row for the items that stay ambiguous. The Present, Missing, or Ambiguous mark is the entry point to that sheet. The priced adjustment is the exit.
The leveling sheet that follows is a grid: scope rows down the side, one column per subcontractor, and beneath each price a set of adjustment rows. A missing item gets a plug, and the plug has to come from somewhere defensible: the price another bidder carried for the same item, a rate from the firm's cost book, or an allowance the estimator is willing to explain. Ambiguous items get a plug and a risk note. Only after the adjustments are added does a column total mean anything, and the sub with the lowest first-page number is often not the sub with the lowest leveled number. The awarded scope letter is then written from the sheet, row by row, so the sub signs the same list the estimator priced.
The check has a hard edge. Battery limits drawn on plans, the line where one trade's work ends and another's begins, are a drawing problem, and models read drawings badly. The scope check that works is a text problem: the firm's written scope against the sub's written proposal, row by row. The drawing review stays with the estimator.
Definitions are the other hard edge. Dark shell, warm shell, and base building are not fixed terms. One owner's dark shell includes a sprinkler main and a roof drain; another's stops at the slab. Whether restrooms, a fire alarm panel, or main HVAC distribution belong to the base building changes by lease and by market. A model asked to check a proposal against a term it defines from general usage will check it against the wrong scope. The desk keeps a definitions sheet per project, written from the lease exhibit and the owner's outline specification, and the checklist rows point at it. The check is only as good as the definitions the firm wrote down first.
The rule on the letter of offer
The same desk had a second case, on the other side of the bid. A hard bid allowed about ten business days where four weeks is usual. The estimator asked a model to verify that the issued drawings matched what the plans claimed existed. The sheets referenced a Project Manual that had never been issued. The model cited the general note on sheet G-010. The bid letter went out with allowances and exclusions for anything not fully drawn.
That is the mirror of the sub-bid check. On the sub side, the question is whether the proposal covers the scope. On the head-contract side, the question is whether the bid covers the requirements, and the requirements hide in hundreds of pages of specifications, contract clauses, and addenda that no estimator reads fully in ten days. A model can read them and produce a register. The rule for the register is binary and belongs to a person: every requirement is either in the price or excluded in the letter of offer. A row that is neither is a variation waiting to be written by the client.
Short rows matter for a reason that is arithmetic rather than editorial. A model that is right 98 percent of the time on a single step is right about 80 percent of the time across ten chained steps and about 60 percent across twenty. Long automated chains compound their errors. A register of small rows, each one checked and signed, does not. That is why the desk's tool produces marks a person confirms, not a verdict.
A gap found once becomes a checklist row
The gap caught on bid day tends to reappear on the job, because the agreement that closed it lived in an email. Questions get answered, subs get told what is in and out, and six months later nobody remembers what was agreed. A correspondence register that logs every answer against the sub is part of the scope check, not an administrative extra. When the variation arrives, the exclusion that lived in an email is on the record.
The loop closes at the end of the job. Compare the variations each sub filed against the scope they were awarded, and every variation is a candidate for the checklist. If the electrical sub charged extra for temporary lighting, the next project's scope template names temporary lighting. The firm's checklist grows one caught gap at a time. That is where the pizza-oven hood lives now, as a row.
Operations runs its own version of this review, usually on a weekend. The project manager who inherits an estimate three months into a job and finds a six-figure miss is doing the same work the estimator did on bid day, with worse options. The scope check has an owner after award too.
What the check does not replace
The tool marks rows. It does not price them, negotiate them, or decide which sub to award. It does not read the drawings, so battery limits, the physical line between the mechanical sub's ductwork and the kitchen sub's equipment, still get drawn by hand with two subs in a room. And it does not know what the firm has learned about a particular bidder over ten jobs, which is often the reason an Ambiguous row is really a Missing one. What it removes is the scanning: reading a hundred proposals for the sentence that is not there, on the two days of a tender when nobody has time to read.
Keep one scope template per trade, and add a row for every variation a sub filed on the last job.
Write the project's definitions sheet before the first proposal arrives, from the lease exhibit and the outline specification.
Mark every row Present, Missing, or Ambiguous, and treat Ambiguous as a priced risk, not a pass.
Plug every Missing row from another bid, the cost book, or a named allowance, and write the award letter from the leveled rows.
Log every answer given to a sub in the correspondence register, so the exclusion that lived in an email is on the record when the variation arrives.
From a scope gap to a checklist row
1Receive three to five quotes per trade package, each with its own inclusions and exclusions
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2Mark each scope item present, missing, or ambiguous against the firm's own definitions
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3Price an adjustment for every excluded or included item so the quotes level
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4Log every email answer and meeting note against the subcontractor in a correspondence register
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5At project end, compare the subcontractor's variations to the initial scope of works
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6Add each variation to the scope gap checklist and update the template scope for the next job
The market has started to sell this check. Provision's Scope Agent went to general availability in August 2026, and its launch coverage named one customer, ProWest Constructors in California. Its president, Michael DeMarie, said the tool cut award-to-subcontract time by about half and that the first live run saved a senior estimator three to four days and surfaced four or five missed items. Those are one customer's numbers on one job, relayed through the vendor's launch. The firm in this story got there with a checklist it wrote itself.