AI-Powered Bar Bending Schedule Platform

Rebar estimation is one of the slowest, most error-prone steps in a construction project. When we started working on BBSteel, the challenges were clear:

• Engineers were reading structural drawings by hand and re-typing every beam, column, slab and footing bar into spreadsheets.
• Drawings arrive in many formats: AutoCAD DWG/DXF, scanned PDF schedules, Revit 3D models and Excel, each labelled differently by every consultant.
• Cutting lengths depend on bar shapes, cover, laps and development lengths, so a single wrong assumption repeats across thousands of bars.
• 12 m stock bars were cut without planning, which meant significant steel wasted as offcuts on every site.
• Large contractors needed organisations, teams and project-level permissions, not a single-user calculator.

The core challenge for us was:

How do we turn complex structural drawings into an accurate, optimised bar bending schedule, automatically and at site scale?

We approached BBSteel as a drawing-to-cutting-plan pipeline: every file goes in once, and the platform handles extraction, calculation, optimisation and reporting.

1. Multi-Format Drawing Import

We built an import layer that accepts the files structural teams already use:

• AutoCAD DWG/DXF parsing with versioned pattern libraries for beam, column, slab and footing labels
• PDF structural schedules read with AI vision, validated before they reach the schedule
• Revit 3D models processed through Autodesk Platform Services to pair each bar with its host element
• Excel import and the option to merge multiple imports into one floor

2. Project Structure That Mirrors the Site

Every project is organised the way construction teams think about a building:

• Projects → Blocks → Floors, with imports attached at floor level
• Developer, contractor and consultant details on every project
• Clone, rename and bulk-create floors for repeating levels
• Per-project access control for each team member

3. Formula-Driven Rod Calculations

Each structural member becomes a set of bars with exact cutting lengths:

• Beam, column, slab and footing elements with their dimensions, cover, concrete and steel grades
• Shape segments (L1 to L6) calculated per bar, with weight per running metre
• Common parameters applied across an import in one step
• Filled and unfilled filters so engineers see exactly what still needs review

4. Shape Library & Visual Formulas

To keep calculations transparent, every bar is tied to a standard shape:

• A shape library of bottom bars, top bars, extra bars, stirrups and more
• Organisation-specific shapes that can be cloned or hidden
• A formula view that shows every substitution step
• Continuous beams and slabs calculated across spans

5. Material Summaries & Dashboards

Results roll up into the numbers site and procurement teams need:

• Element-wise tonnage by bar diameter, from 8 mm to 40 mm
• Diameter-wise estimate and waste charts per project
• Organisation dashboard with projects, imports and total estimated tonnage
• One-click Excel and PDF exports

6. Cutting-Stock Waste Optimisation

The biggest saving came from planning how each 12 m bar is cut:

• Bars packed into stock lengths using optimisation algorithms sized for thousands of rows
• Laps handled automatically for bars longer than 12 m
• Offcuts tracked in a waste inventory so they can be reused
• Heavy optimisation runs in background workers, keeping the app responsive

7. Teams, Subscriptions & Administration

BBSteel runs as a multi-organisation SaaS product:

• Organisation admins manage users and granular project permissions
• Subscription plans, add-ons and online payments
• A platform admin area for master data, shapes, pricing and customers
• Secure cloud storage and a queue-based architecture built to scale

Key Features Delivered

• DWG, PDF, Revit & Excel Import
• AI-Based Schedule Extraction
• Project, Block & Floor Structure
• Shape-Based Cutting Length Engine
• Common Parameters & Bulk Edits
• Element & Diameter-Wise Tonnage
• Cutting-Stock Waste Optimisation
• Waste Inventory Tracking
• Excel & PDF Exports
• Teams, Roles & Subscriptions

Every feature was designed to make rebar estimation faster, more accurate and less wasteful.

BBSteel has been built as a platform that turns structural drawings into optimised bar bending schedules.

Impact

• Hours Instead of Days: Schedules that took engineers days of manual take-off are generated from the drawings themselves
• Fewer Calculation Errors: Formula-driven lengths and standard shapes remove repeated manual mistakes
• Less Steel Wasted: Cutting-stock optimisation and offcut tracking reduce scrap on every project
• One Source of Truth: Projects, floors, imports and exports live in one place for the whole team
• Built for Large Contractors: Organisations, permissions and subscriptions let the platform scale across sites