For electrical contractors, the estimating bottleneck is almost always the takeoff - the manual process of reading through every drawing in a set, identifying every component, counting quantities, and transcribing everything into a spreadsheet or estimating system. It is slow, prone to error, and scales only by adding headcount. OpenDrawing automates the extraction step, turning a full-day task into a 5-minute review.
What Gets Automated
From schematic and single-line drawings: OpenDrawing identifies and counts every electrical component - breakers, panels, transformers, disconnects, meters, relays, motor starters, contactors, and dozens of other component types - and reads the specifications annotated beside each symbol (voltage rating, current rating, phase count, ampere frame, manufacturer callouts). The result is a complete component list with quantities and specifications, ready for pricing.
From conduit schedules and wire schedules: When the drawing package includes conduit schedules or wire schedules, OpenDrawing extracts the run data - conduit size, type, quantity, and length; wire gauge, insulation type, and quantity - and includes it in the takeoff output alongside component counts. Wire and conduit quantities within diagrams (where runs are shown graphically but not scheduled) require a schedule document for automated extraction; if no schedule is present, the component BOM is still extracted in full.
The Bidding Volume Impact
A typical commercial electrical project drawing package takes an estimator 6–10 hours to manually take off. An estimator working 50 weeks per year can complete 25–35 bids per year at that rate, assuming takeoff is 60–70% of their estimating labor.
With automated takeoff, the same estimator reviews a pre-populated BOM in under 5 minutes. Bidding capacity rises to 200+ projects per year for a single estimator - not because they are working faster, but because the extraction step no longer consumes most of their time. The estimator's value shifts from data entry to judgment: bid/no-bid decisions, scope review, pricing strategy, and relationship management.
Accuracy and the Review Step
Automated takeoff accuracy on clean PDF drawing sets is typically 90%+ for component identification. The review step is not optional - it is a fast quality check, not a re-do from scratch. The estimator scans the extracted list against the drawings for omissions or misreads, makes corrections where needed, and approves the BOM for pricing. That review takes under 5 minutes on a typical commercial drawing set, versus 6–10 hours of manual extraction.
Low-confidence items are surfaced automatically in a review queue, so the estimator's attention goes directly to the items that need it rather than re-reading every page.
Integration with Estimating Systems
The extracted BOM exports to Excel and CSV for import into any estimating platform. For teams using Accubid, Trimble Estimation, or similar specialized electrical estimating software, the export format maps to the standard import schema. For teams using general estimating tools (Bluebeam, Procore, or custom spreadsheets), the Excel export loads directly without reformatting.
When a parts catalog is uploaded, the BOM also includes matched supplier part numbers and pricing references, further reducing the manual lookup step in the estimating process.
Getting Started
The fastest way to evaluate the fit is to send us a drawing package from a recently-completed project, one where you already know the correct quantities, and compare the extracted BOM against your manual takeoff. That comparison gives you a concrete accuracy reading on your specific drawing types before you rely on it for live bids.