Definition and Overview
Industry Foundation Classes (IFC) is an open, international standard developed by buildingSMART International that defines a comprehensive data model for representing building and infrastructure information. The IFC format enables seamless data exchange between different software applications used in architecture, engineering, construction, and surveying disciplines, regardless of the platform or vendor.
As a non-proprietary file format, IFC files (.ifc) contain standardized information about physical elements, spatial relationships, and project metadata that surveying professionals need to document and exchange with other stakeholders in the built environment.
Technical Specifications and Data Structure
IFC Format Architecture
IFC is based on the ISO 16739 international standard and uses either EXPRESS data modeling language or XML formatting for data representation. The standard currently includes over 700 entity types and 400 property definitions, allowing comprehensive documentation of:
File Format Options
IFC data can be stored in multiple formats:
IFC (STEP format): The native EXPRESS-based format using ASCII text IFC XML: An XML serialization of IFC data for web-based applications ifcJSON: A JSON representation enabling integration with modern web technologies
Each format maintains identical semantic content while offering different advantages for specific software environments and data processing workflows.
Applications in Surveying and Geomatics
BIM Integration and Data Exchange
Surveyors increasingly use IFC as the primary mechanism for exchanging Building Information Models (BIM) with architects, engineers, and contractors. When surveying existing structures or sites, professionals can export survey data directly into IFC format, enabling seamless integration with design and construction workflows.
The IFC standard includes spatial elements such as IfcBuilding, IfcBuildingElement, and IfcGeographicElement, which allow surveyors to represent site features, building footprints, and infrastructure networks within a standardized framework.
Site Survey Documentation
Modern surveying instruments and software now support direct IFC export capabilities. Survey data including:
Can be documented in IFC format, providing clients and project teams with standardized, interoperable documentation.
Clash Detection and Coordination
When combining survey data with architectural and engineering models, IFC enables automated clash detection between surveyed existing conditions and proposed elements. This coordination function is essential for renovation projects, infrastructure upgrades, and site development planning.
Related Instruments and Software Integration
Survey Data Collection
Total stations, GNSS receivers, and laser scanners increasingly include software that can export point clouds and measured data in formats compatible with IFC conversion. Level instruments and theodolites integrated with digital data collection systems support workflows that ultimately produce IFC-compliant documentation.
CAD and BIM Software
Professional surveying packages and CAD platforms including Autodesk Civil 3D, Revit, and specialized surveying software provide IFC import/export functionality. These tools allow surveyors to work with native survey data while maintaining IFC compatibility for stakeholder distribution.
Practical Examples in Survey Practice
Existing Building Survey
A surveyor documenting an existing building for renovation planning uses laser scanning and manual measurements to capture:
This survey data is organized within the IFC framework, where building elements are classified as IfcWall, IfcWindow, IfcDoor, etc. The resulting IFC model provides architects with surveyed existing conditions for their renovation design.
Infrastructure Inventory
A municipal surveyor conducting a utility network survey collects data on water mains, sewer lines, and electrical conduits. Using IfcDistributionElement and related classes, this infrastructure data is structured in IFC format, enabling facility management systems and future maintenance coordination.
Site Development Project
For a greenfield development, a surveyor prepares a site survey including topography, boundary lines, and existing features. The IFC model organizes this information with site context data, allowing planners and engineers to develop designs that incorporate surveyed baseline conditions.
Advantages and Implementation Considerations
Benefits for Surveying Practice
Implementation Challenges
While IFC adoption continues growing, surveyors should recognize that:
Conclusion
IFC represents the evolving standard for surveying data exchange in integrated project environments. As BIM methodologies become industry standard, surveying professionals must understand IFC capabilities, limitations, and implementation requirements to effectively document existing conditions and site information in formats that facilitate collaboration throughout the project lifecycle.