IFC → STEP AP242 · PhD Research

From BIM to
Fabrication.

No Data Lost. // IFC → STEP AP242 · With PMI

OffBIM converts IFC building models into manufacturing-ready STEP AP242 files — preserving hole geometry, tolerances, and assembly data that every other tool silently discards.

.IFC IFC 4.x / 2x3 STEP AP242 ISO 10303-242 + PMI + Holes IfcOpeningElement CYLINDRICAL_SURFACE ✓ NIST Validated AP242 Ed.1 2014
See It In Action

From BIM to Fabrication-Ready STEP

Four capabilities. One pipeline. Zero manual translation.

AP242 Hole Feature Annotation

OffBIM detects cylindrical openings from IFC geometry and exports them as CYLINDRICAL_SURFACE entities in a conformant AP242 STEP file — ready for CNC and fabrication systems.

  • Automatic hole detection from IfcOpeningElement and B-rep geometry
  • CYLINDRICAL_SURFACE per hole in AP242 DATA section
  • Batch export across 50 elements per file

Geometric Tolerance Export

Dimensional tolerances defined in BIM are preserved and exported as companion JSON metadata alongside the STEP file.

  • Tolerance data from IFC property sets
  • JSON companion file per exported batch
  • Compatible with assembly reports

Assembly Structure Export

Multi-part assemblies exported with hierarchical relationships intact — NEXT_ASSEMBLY_USAGE_OCCURRENCE entities preserve parent-child structure.

  • Full assembly tree preserved in STEP
  • Placement transformations per component
  • Compatible with CAM and fabrication tools

IFC-to-STEP Entity Mapping

OffBIM maps IFC semantic entities to their STEP AP242 equivalents without information loss.

  • 12 IFC entity types supported
  • Geometry and semantic metadata preserved
  • Validated against NIST STEP Analyzer

What OffBIM
does for you

01 /

Hole Feature Extraction & PMI

Extracts IFC opening elements and reconstructs them as analytically exact CYLINDRICAL_SURFACE entities in STEP AP242 — the geometry IfcConvert silently destroys.

ISO 10303-242 · PMI
02 /

Manufacturing Reports

Generates tolerance reports, assembly relationship reports, and BIM-to-manufacturing mapping files — the Manufacturing Information Requirements your project is missing.

MIR · JSON · CSV
03 /

Individual Element Export

Select any element from your model and export it individually as STP, STL, OBJ, or AP242. Because manufacturing happens one component at a time — not the whole building.

STP · STL · OBJ · AP242
04 /

Geometry Analysis & BOM

Analyses geometry complexity, extracts Bill of Materials, and classifies elements by manufacturing readiness — giving fabricators the data they need before a single cut is made.

BOM · Complexity · DXF

Four-stage
conversion engine

STAGE 0
IFC Semantic
Extraction
Holes manifest
+ GUID mapping
STAGE 1
IFC → Geometry
Conversion
Standards-based
conversion
STAGE 2
AP214 → AP242
Post-Processor
Schema upgrade
+ hole injection
STAGE 3
NIST SFA
Verification
AP242 Ed.1
compliance check

Built on peer-reviewed
research. STEP output verified
using the NIST STEP File Analyzer.

OffBIM is the output of a PhD research programme validated by 27 construction industry professionals across six dimensions including relevance, effectiveness, and intention to adopt.

Validators
27+
Performance
480×
Standard
AP242
Institution
Research