ConstructionHVAC Quantity Extraction: Cut 4-6 Hours Per Plan
Automated HVAC quantity extraction from CAD and PDF reduces estimation error to under 0.5% and eliminates 4-6 hours of manual work per plan revision.
What automated ITO and AI takeoff read (PDF, DWG, IFC, Revit), what they extract, how a quantity traces to its sheet and where an estimator still checks.
Automated quantity takeoff, also called automated ITO (information takeoff), means the software reads your construction documents and returns structured quantities instead of an estimator measuring them by hand. AI agents ingest PDF and DWG drawings, or IFC and Revit models, identify walls, openings, slabs, pipe runs and equipment, then output lengths, areas, volumes and counts mapped to your cost codes. The estimator's work moves from measuring to validating: checking the flagged lines and the quantities that drive the price.
See AI quantity takeoff for contractors: quantities read from your plan sets, each traced to its source sheet.
ITO is the model side of the same job: pull quantities, properties and locations out of a BIM model and report them in a structured table. Teams use it for gross area analysis at project start, space and supply lists before tendering, quantity surveying for contract packages, and checking that the model carries the data it should, since a missing property shows up as an empty cell. AI adds the part that used to be manual: recognising entity types, generating measurement rules, assigning the right metric and grouping lines by trade and cost code.
When the source is a live model, the agent reads entities and their quantity sets directly, with no PDF round trip, and respects phase and design option filters so demolished or temporary works do not pollute the bill of quantities. Volume goes to concrete and masonry, length to piping and cable trays, area to partitions and glazing, count to doors and fittings. Accuracy tracks modelling discipline: well-modelled projects at LOD 350 and above approach line-item parity with a manual takeoff, while lower-detail models need parameter cleanup or category remapping first.
Most bid packages are still 2D, so computer vision does the reading: it counts matching symbols for doors, windows, fixtures and equipment, detects enclosed rooms to build area quantities, traces pipes, ducts and cable trays into running lengths, and pulls door, window and finish schedules straight off the sheets. A complete multi-sheet package is processed in one pass and sorted into architectural, structural and MEP sets. Two settings decide whether the numbers are usable: the calibrated scale, and the boundary rule, inner edge, outer edge or centreline, which has to match your measurement standard.
OCBM: 100% of quantities traceable, zero without a source.
See the case studyManual quantity takeoff on a mid-size building takes several engineer days, and it is repeated at every plan revision. When owners issue intermediate updates or architects revise details, your team restarts the measurement work from scratch, reading dimensions from CAD files, calculating areas and volumes by hand, and typing values into spreadsheets. Each cycle introduces transcription errors and delays bid delivery.
The cost compounds across revisions: every intermediate revision restarts part of the measurement. Measurement takes much of the time estimators would rather spend on analysis, risk assessment or commercial negotiation. There is also no standard between surveyors, so two people measuring the same floor plate produce two structures of data that cannot be compared or reused as historical cost evidence.
Inconsistencies between plan quantities and written specifications often go undetected until after bid submission. Requirements buried in addenda create post-award surprises, and revision tracking done with email attachments leaves the constant risk of estimating from a superseded drawing set.
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AI agents ingest PDF and DWG construction plans and identify geometric elements: walls, openings, floor slabs, roof surfaces, pipe runs, cable trays and equipment locations. The system reads dimensions, material callouts and annotations from plan geometry and text layers, then calculates derived quantities without user intervention. Linear meters, surface areas, volumes and counts populate structured takeoff sheets that map to line items in your bill-of-quantities format.
When a revised set arrives, the agent re-runs the same measurement rules and compares the result with the previous run. Instead of re-measuring, the estimator reads a change list: which quantities moved, by how much, and which elements or sheets drove the movement. Snapshots of each takeoff state let you show a cost committee exactly what changed between two issues, and which design decision caused it.
Every extracted line should cite its source, the model element ID or the drawing region it came from, so a reviewer can answer "where did this number come from" in one click. On 2D packages, colour-coded markups on the original PDF serve the same purpose and can be shared with subcontractors as scope evidence. Tender documentation and public procurement generally require this audit trail, and it is also what keeps review fast enough to preserve the time saved.
Integration with estimating platforms like Candy, Cubicost and WinQS happens through standard APIs or CSV import pipelines, so quantities flow into your cost model without re-keying. Structured Excel output remains the fallback where no API exists. Accuracy improves because the transcription step between plan quantities and bill of quantities disappears at the source.
On standard elements such as walls, slabs, roof areas and floor finishes, AI extraction is reliable when drawings are clear and complete. Specialty items, equipment, custom details and non-standard callouts still need human verification. The realistic target is not autonomy but a review budget: plan to spot-check a share of the extracted quantities, more on the first projects, and measure the error rate on your own drawings.
Accuracy is mostly a function of the source documents. Hand-sketched dimensions, poorly scanned PDFs, inconsistent line weights, unnamed CAD layers and missing callouts all push results down, and the cleanup work eats the time saved. Agree with your design partners on consistent text height, clear dimension placement and named layers; on model-based work, agree on parameter discipline before the first run.
Confidence scoring is what makes review efficient. The system flags ambiguous or low-confidence results instead of presenting every line with the same weight, so the estimator checks the flagged items rather than re-reading the whole package. Before trusting output on a live bid, run a full extraction against your last manual takeoff on the same project and compare line by line.
Do not let the tool impose its own line-item structure. Map extraction output onto your existing cost codes, regional standard or in-house item definitions, then save that mapping as a template. Reusable measurement rules are what make every later project of the same type faster to price.
AI extraction reduces takeoff time at every revision, and the estimator reviews instead of measuring. Teams testing automated takeoff against manual measurement report gains of up to 80% once drawing standards are stable, and the gain repeats with each intermediate revision.
Manual takeoffs carry dimensional and calculation errors that propagate into the bid and resurface as post-award disputes. Extraction removes the transfer step between plan quantities and bill of quantities, so the cost estimate corresponds to what the design actually specifies. Rules stay identical across every building in a portfolio bid, which also removes the surveyor-to-surveyor variation that makes historical data hard to reuse.
The time currently spent on measurement moves to specification reconciliation, subcontractor scope clarification and pricing strategy. Estimators compare alternatives, challenge quotes and identify optimisation opportunities instead of counting doors.
Manual workflow: the estimator receives the bid package, displays or prints the drawings, identifies every wall, opening and duct run, measures with a scale or markup tool, types quantities into spreadsheets, scans cross-sections for discrepancies and compiles a final list. Accuracy bottleneck: human measurement error, missed details, inconsistent scaling.
AI workflow: the package is uploaded, the system processes architectural, structural and MEP sheets in one pass, and the quantities come back for review. The estimator checks the output against key sections, confirms completeness, adds project-specific notes and flags unusual conditions. Accuracy bottleneck: edge cases and obscured details only.
The core difference is the inversion of effort. Manual work is mostly extraction, with judgement squeezed in at the end; the AI workflow is mostly validation and judgement. For a firm handling many bids per quarter, that redirection compounds: estimators spend less time per package and can review several packages in parallel.
AI takeoff is highest-value for general contractors and large specialty subcontractors processing 10 or more bids per quarter. Quantity surveyors, bid managers and estimating teams on commercial or industrial projects with complex geometry, multiple revisions or tight deadlines see return first. Deployment makes economic sense when your average bid cycle includes 2 or more plan revisions, your plans exist in digital format, and measurement is still manual.
If your design teams already work in Revit or ArchiCAD, quantities can come straight from the model or its IFC export, which shortens setup. Integration with project management platforms such as Procore or Autodesk Construction Cloud keeps quantities synchronised across estimating and operations. Start with straightforward typologies, commercial buildings, simple structures, well-organised utility runs, and expand after 5 to 10 successful extractions.
Fit-out and renovation packages suit automation because the quantities are repetitive and room-based: partitions, ceilings, floor finishes, doors, light fittings, small power. Room detection and symbol counting cover most of a floor plate, and a room-by-room schedule falls out of the same pass, which is exactly what an office renovation bid needs. Two cautions: scanned as-built drawings need scale verification before anything else, and existing conditions that never appear on the drawings, live services or structural surprises, remain a site survey question.
An outsourced takeoff agency buys you capacity for a peak, at a fee per package and with a turnaround you do not control, and each revision is usually a new order. Automation buys a capability that keeps the measurement rules, cost code mapping and revision history inside your team. Many contractors run both: the agency absorbs overflow on unusual typologies, the agents handle recurring project types where templates already exist.
Drawings, bills of quantities and unit rates are commercially sensitive, so settle three questions before any pilot. Does the contract allow the supplier to train models on your documents, and can that be excluded in writing? Where does processing happen, in your own tenancy or on a shared platform, and how long is data retained after project close?
Mirage engineers deploy inside the client's environment and connect the agents to the systems already in place, so plans and cost data stay where your IT policy and your client contracts require them. If a supplier cannot describe the data path from upload to deletion, treat its accuracy claims as secondary. Enterprise and public tenders increasingly ask this before they ask about features.
See which AI estimating software fits a contractor: what each tool measures, how AI estimating works and what a rollout involves.
Pricing usually takes one of three shapes: per-estimate usage, a seat or volume subscription, or a deployment fee plus integration work. Compare offers on the cost per completed, reviewed bid, integration included, rather than on the headline price. At Mirage, prices start at $10,000 to launch and $1,000 a month, priced by volume. Budget time for configuration and for validating the output on a few representative projects before relying on it.
To judge the return, compare the loaded hours an estimator spends on takeoff per package with the hours spent reviewing automated output, multiply by your bid volume, and set the difference against the launch and subscription cost. Use your own timesheets: hourly rates and takeoff hours vary too much between firms for a generic figure to mean anything.
A mid-size commercial bid runs through takeoff, pricing research, subcontractor outreach, assembly and contingency, and management review, and takeoff is the step the others wait for. With quantities available early, outreach starts with real quantities, so quotes come back while there is still time to negotiate scope.
With measurement automated, the same estimating staff can pursue more bids, because the hours previously spent measuring come back on each project. Judgement work does not grow with it; it simply stops being gated behind measurement. Estimators who review output and make commercial calls tend to stay longer than those who trace lines alone, and replacing an experienced estimator costs more than the software.
Generic cost databases publish national averages: concrete at X per cubic yard, steel at Y per ton. Your crew productivity, your subcontractor agreements and your site conditions differ. A tool that prices national averages either bids against your real cost structure and loses, or wins too tight.
Estimating software connected to your ERP works from your own record: completed projects, actual unit costs for concrete, steel, drywall and electrical work, crew productivity read from historical schedules and timesheets, and the rates you hold with regular subcontractors. This calibration matters most on high-risk line items, where published rates fit worst. High-risk items are complex formwork, electrical systems with non-standard loads and HVAC scopes with special commissioning.
The same history gives you a second safeguard: variance flagging. A new estimate shows 800 linear feet of underground conduit at $42 per foot while your average is $35, and the system raises it before submission. Is it the region, deep burial, rock? The point is to catch the preventable estimating errors before the bid goes out.
Construction drawings are not standardised. Each architect uses different notation, scale and layering conventions, so estimators decode plans before they can measure anything. Unlike document processing in finance or legal services, construction AI tools must handle visual ambiguity, plan revisions and layering logic that changes from one project to the next.
A 3% error on a $50M bid is $1.5M of misallocated margin, and senior estimators still spend much of a bid cycle on manual takeoff and bid assembly for a mid-size commercial building. The tooling splits into three layers: quantity takeoff automation, cost database integration, and bid intelligence for assembly, review and risk flagging. The margin difference between a tight bid and a missed obligation is why automation here compounds value.
For a commercial project, compare six things: source formats accepted (PDF, DWG, IFC, Revit), whether revisions are diffed automatically, how lines map to your cost codes, export targets, the review and traceability interface, and the deployment model, cloud or inside your environment. Accuracy claims mean little until they are run on your own drawing conventions, which is why a pilot on 5 to 10 real bids is the only reliable test.
Togal.ai (togal.ai) uses computer vision to extract quantities from PDF plan sets, reading line types and annotations and generating a structured takeoff that feeds estimate templates, with automatic comparison between plan revisions. Best for general contractors and design-build firms running 50 or more bids per year with reasonably standardised plans. Limitations: it struggles with hand-drawn or heavily annotated sets, and exports are CSV-based, so mapping to your estimating software is manual.
DESTINI Estimator (becktechnology.com) combines cost modelling with historical project data to produce parametric estimates early in design, flagging scope creep and budget variance before detailed takeoff starts. Best for preconstruction and GC teams bidding several project types who need early-stage estimates, and firms with ten or more years of cost history. Limitations: it needs clean historical data to be reliable, and it is not built for specialty subcontractor pricing or trade-specific labour variance.
Construction Intelligence by Mirage Metrics (miragemetrics.com/construction) runs three agents on different layers of the estimating problem. The Plan Reading Agent extracts dimensions and rolls up quantities (at John Cockerill, piping takeoff takes 80 to 90% less time); the Cost Estimation Agent feeds those quantities into the client's own estimating system and rates, with a human review before anything is priced; the Project Tracking Agent watches bid deadlines and project status across emails and documents. Best for contractors and engineering groups with recurring drawing conventions: a proof of concept on your own plan set one week after the first meeting, the first workflow in production in 4 to 6 weeks, and integration into the existing estimating system can take longer.
Autodesk Takeoff (autodesk.com/construction) handles both PDF and model-based (Revit, IFC) takeoff in the cloud, links items to cost codes in the connected estimating module, and syncs revisions automatically. Best for firms already working in Revit and Construction Cloud, where BIM models carry usable parameters. Limitations: it is tied to the Autodesk ecosystem, export elsewhere goes through CSV translation, and poor model coordination directly degrades the takeoff.
Buildxact (buildxact.com) is a mobile-first estimating platform with cost lookup and a historical pricing database, where estimators enter scope by voice or text and get a branded quote in minutes. Best for home builders, remodelling contractors and small commercial shops quoting similar work repeatedly. Limitations: the cost database is USA-focused and tuned to residential work, and there is no takeoff from plans, so scope is entered manually.
Procore (procore.com) is a project management platform with estimating and bid management modules that connect estimates to actual field costs, labour hours and material consumption. Best for large GCs wanting one platform from bid to financial close. Limitations: estimating is secondary to project management, dedicated takeoff tools extract quantities faster, and implementation with data migration is a project of its own for mid-size firms.
PlanSwift (planswift.com) is on-premises takeoff software built for mechanical, electrical, plumbing and roofing subcontractors, with trade templates and automatic rollup for repetitive assemblies. Best for trade shops bidding 20 to 200 projects per year where material counts drive margin. Limitations: measurement is manual rather than automated, so gains come from interface speed and templates, and there is no cost database integration beyond Excel export.
The first decision is bid volume and firm size. GC estimating at scale, 100 or more simultaneous bids across several estimators, points to Mirage Metrics or Procore for multi-team workflows and deadline tracking. Mid-market builders bidding 30 to 80 projects per year should test Togal.ai or Buildxact for takeoff speed and cost lookup, while specialty subcontractors weigh PlanSwift against Buildxact depending on whether they need on-premises control or mobile simplicity.
The second decision is fit with your existing stack and your data rules. If design runs on Revit and Construction Cloud, Autodesk Takeoff or DESTINI are natural; if you are platform-agnostic and need weeks of bid preparation compressed, the agent-based route gives the largest speed gain per euro. Run a pilot on 5 to 10 real bids, measure extraction accuracy on your own drawing conventions, and confirm in writing what happens to your documents after processing.
John Cockerill: 80-90% less time on piping takeoffs.
See the case studyTry it on your own drawings: send one plan set and we send back what our agents extracted and flagged. No call needed.
ITO stands for information takeoff: extracting quantities, properties and locations from a BIM model and reporting them in a structured table. Automated ITO uses rules and AI to identify entity types, assign the right metric to each category, group lines by trade and cost code, and re-run on every model issue. Drawing-based AI takeoff does the same job from PDF and DWG sheets using computer vision.
On standard elements such as walls, slabs, roof areas and finishes, extraction is reliable when drawings are clear and complete. Specialty items, custom details and non-standard callouts need human checking, and model-based takeoff depends on modelling discipline: low-detail models require parameter cleanup first. Plan a share of lines for review on the first projects, and validate one full extraction against your last manual takeoff.
Only if your contract allows it, so make it explicit before any pilot. Ask whether training on your documents can be excluded in writing, where processing happens, in your own environment or on a shared platform, and how long files are retained after project close. Mirage engineers deploy inside the client environment, so plans, rates and bills of quantities stay under your own IT and client obligations.
Pricing models differ: per estimate, per seat or volume subscription, or a deployment fee plus integration. At Mirage, prices start at $10,000 to launch and $1,000 a month. The return depends on your own figures: the loaded hours an estimator spends on takeoff per package, the hours spent reviewing automated output, and the number of bids you run each year.
An agency gives you capacity for a peak, priced per package, with each revision treated as a new order and the measurement logic staying outside your team. Automation keeps the rules, cost code mapping and revision history in-house, which matters when a project runs through several drawing issues. Many contractors combine both: the agency handles unusual one-off typologies, agents handle recurring project types.
It reads the new sheet set, compares each quantity with the previous revision and flags what changed, with the sheet each change comes from. The estimator reviews the changes instead of measuring the whole set again.
Most cloud takeoff tools let several users open the same project; check whether edits lock by sheet or by item. When an agent produces the takeoff, the team's work moves from measuring to reviewing the items it flags, which can be split by trade.
On repetitive, clearly drawn elements, yes; the gain shrinks on custom details and poor scans. On John Cockerill's piping takeoffs, Mirage cut the time spent by 80 to 90 percent (see the John Cockerill case study).
ConstructionAutomated HVAC quantity extraction from CAD and PDF reduces estimation error to under 0.5% and eliminates 4-6 hours of manual work per plan revision.
Construction10 AI estimating and takeoff tools compared on plan formats, traceability, review step, integrations and pricing, from vendor pages read in October 2026.
ConstructionEliminate hidden contradictions between plans and specs before bid. AI cross-references 100% of documents in under 2 hours, reducing change orders by