Glossary

Construction estimating, defined.

44 terms covering takeoff, bidding, contracting, code references, and the OmniTakeoff approach. If we're missing something, tell us.

A

Active learning loop: A training pipeline where every confirm/reject decision on a vision claim becomes ground truth that retrains a per-org symbol recognizer. Compounds accuracy with every project.
Addendum: A formal amendment to bid documents issued by the architect or owner before bid submission. Numbered (Addendum 1, 2, 3...) and incorporated by reference into the bid.
Assembly: A reusable bundle of line items representing a standard work package — e.g. '20A duplex receptacle circuit' includes box, device, faceplate, conduit, wire, and labor hours.

Bid bond: A surety bond submitted with a bid guaranteeing the bidder will sign the contract if awarded. Typically 5-10% of the bid amount.
Bid leveling: The GC's process of comparing sub bids on a common scope basis. Differences in inclusions/exclusions/clarifications get reconciled before pick.
Bid window: The period from when bids are due until they're opened. Some public bids have a sealed-bid window where pricing can't be revised.
BIM: Building Information Modeling. 3D federated models that combine architectural, structural, and MEP design. Source files are typically Revit (.rvt) or IFC.
Bond: Short for surety bond. Construction context: bid bonds, performance bonds, payment bonds. Each guarantees a different obligation.
Bonding capacity: The maximum bond amount a contractor can carry. Typically expressed as 'aggregate' (total all open jobs) and 'single project' limits.
Buyout: The post-award process where the GC signs subs to scope packages. Bid hand-off → buyout is the highest-leverage phase for cost certainty.

Change order: A formal change to scope, schedule, or price after contract execution. Tracked with a CO log; each entry has reason, pricing, and schedule impact.
Confidence-gated review: A workflow pattern where AI claims below a threshold land in a manual review queue, while high-confidence claims auto-progress.
CSI MasterFormat: Construction Specifications Institute's standard organization of construction work. 50 divisions, e.g. Division 26 = Electrical. The North American standard.
CSI section: A specific section within a CSI division, e.g. 26 27 26 = Wiring Devices. Six-digit format: division (26) + level-2 (27) + level-3 (26).

Equipment schedule: A table on the drawings listing equipment items with tag, capacity, manufacturer suggestion, and notes. Common on M, P, E, FP sheets.
Evidence link: A bidirectional reference between a takeoff line and its source on the plans (page, bbox, OCR snippet). Click the line, jump to the page; click the page, see the lines that depend on it.

Final close: The process of locking the bid number and submitting. Bid-day defects caught here are caught too late.

GC: General Contractor. The prime contractor who holds the contract with the owner and subcontracts trade work.
Ground truth: A confirmed (estimator-validated) annotation that becomes part of the training corpus. Distinct from a model's prediction.

Hard-bid vs. negotiated: Hard-bid: lump-sum bid against fixed scope, lowest qualified bidder wins. Negotiated: GC selected on qualifications + open-book pricing. Different bid workflows.

IFC: Industry Foundation Classes. Open BIM file format. Source-of-truth for federated 3D coordination, cleaner than Revit format for cross-tool exchange.

JHA: Job Hazard Analysis. Pre-task safety document identifying hazards and mitigation steps. Often required for OSHA-regulated activities.

Labor unit: Hours required to install one unit of work. E.g. '0.25 hours per receptacle.' Multiplied by quantity to get labor hours, multiplied by labor rate to get labor cost.
Line item: One row in a takeoff or estimate: description + quantity + unit. Aggregates into scope breakdowns and division rollups.

Markup: Multiple meanings depending on context: (1) drawing annotations made on PDFs (Bluebeam-style), (2) the contractor's overhead + profit added to direct costs.
MEP: Mechanical, Electrical, Plumbing. The 'building services' trades. Often bundled as a single design discipline (MEP engineer).

NEC: National Electrical Code (NFPA 70). The default electrical safety standard in the US. Updated every 3 years.

On-Screen Takeoff (OST): A specific takeoff product (sometimes generic). Manual click-to-count workflow on a digitized plan.

PlanSwift: Established takeoff product. Manual measure tools on plans. OmniTakeoff's evidence-first AI is the alternative.
Prevailing wage: Government-mandated minimum wage for public projects. Varies by state, county, and trade. Davis-Bacon (federal), state PW laws.
Procore: Construction management platform. We integrate as a Verified Marketplace partner — two-way document + RFI + submittal sync.
Punchlist: Items remaining at substantial completion that need fixing before final acceptance. Tracked through close-out.

RFI: Request for Information. A formal question from a contractor to the architect/owner during construction. Tracked with auto-numbering and response deadlines.
RFP / RFQ: Request for Proposal / Request for Qualifications. Pre-bid documents soliciting interest. RFQ asks for qualifications; RFP asks for proposals/pricing.
RSMeans: Industry-standard cost reference data. City cost index, crew composition, labor units. We integrate live RSMeans as a fallback pricing source.

Scope of work: A document detailing what's included in a contract — divisions, specific items, exclusions, clarifications. Often CSI-organized.
Spec section: Written specifications organized by CSI section. Distinct from drawings; specs control performance + materials, drawings control geometry.
Submittal: Documentation provided by a contractor to the architect/owner showing what they'll install — shop drawings, product data, samples. Tracked in submittal logs.

Takeoff: The list of materials and quantities derived from drawings. The first major output of the estimating process.
Takeoff line: One row in a takeoff. Has description, quantity, unit, optional CSI division, and an evidence link back to the source on the plans.
Trade: A specific construction discipline — electrical, plumbing, mechanical, fire-protection, etc. Distinct from CSI division (which is a way of organizing scope).

Vector PDF: A PDF where text and geometry are encoded as vector primitives, not pixels. Distinguishes from scanned/raster PDFs that require OCR.
VOREEX / Vorrex: Construction estimating + takeoff software. Considered a benchmark in the AI takeoff category. OmniTakeoff differentiates on evidence-first design and active-learning loops.

Win rate: Percentage of bids submitted that the contractor wins. Industry average: 15-20% in commercial; varies wildly by trade and region.

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