BIM File Formats: Technical Reference for AEC Workflows

What is a BIM file

This reference documents the BIM file formats encountered in production AEC workflows: their file extensions, the software that reads and writes them, the use case they serve, and the technical notes worth knowing before working with them.

Native (proprietary) authoring formats

.rvt — Autodesk Revit Project File

Binary project file containing model elements, families, views, sheets, schedules, and worksharing metadata. Read and written by Autodesk Revit only. Version-locked: a 2024 file cannot be opened in 2022 Revit. Companion files include .rfa (family files), .rte (project templates), and .rvs (Revit Server). The format dominates AEC BIM authoring in North America.

.pln — Graphisoft ArchiCAD Project File

Single-file project format storing model, layouts, libraries, and views. Read and written by Graphisoft ArchiCAD. Companion formats: .pla (archived project including library), .tpl (template). Strong in European architectural markets and in studios prioritizing macOS workflows.

.nwf — Autodesk Navisworks File Set

Reference file pointing to multiple source files (RVT, IFC, DWG, etc) federated into a single coordination view. Lightweight: it stores references, not geometry. Each referenced file generates a .nwc cache.

.nwc — Navisworks Cache File

Compiled geometry cache exported from a source authoring tool (Revit, ArchiCAD, MicroStation). Read by Navisworks; not edited directly. Each .nwc represents one source file in the federated model.

.nwd — Navisworks Document

Published static federated model. All source geometry baked into a single file. Read by Navisworks Freedom (free viewer) without needing the source files. Used for issuing federated models to consultants, clients, and field teams.

.dgn — Bentley MicroStation Design File

Native format for Bentley MicroStation and the broader Bentley OpenBuildings / AECOsim ecosystem. Dominant in infrastructure, transportation, and process industry projects. Includes 2D, 3D, and BIM authoring capabilities depending on the Bentley product variant.

Open (non-proprietary) exchange formats

.ifc — Industry Foundation Classes

The cornerstone of OpenBIM exchange. Defined by the IFC schema from buildingSMART. ASCII or compressed binary (.ifczip). Current version IFC 4 (ISO 16739:2018), with IFC 4x3 adding infrastructure entities. Every major BIM authoring tool supports IFC export and import. Tradeoffs: large file size, some loss of authoring fidelity (parametric families flattened to generic geometry), but universal compatibility for cross-tool federation and long-term archival.

.bcf — BIM Collaboration Format

Zipped XML files carrying issue tickets, viewpoints, screenshots, and comment threads tied to model elements. Does not carry geometry. Used to route clash detection issues, design review comments, and coordination questions between tools (Navisworks, Solibri, BIMcollab, Autodesk Construction Cloud).

.ids — Information Delivery Specification

XML specification defining the information requirements for a BIM deliverable. Used to validate models against client information requirements under ISO 19650 workflows. Newer format, increasing in adoption among public infrastructure clients in Europe and the UK.

.xlsx (COBie) — Construction Operation Building Information Exchange

Spreadsheet-format deliverable carrying asset data for facility management. Standardized worksheet structure (Contact, Facility, Floor, Space, Type, Component, System, Assembly, etc). Extracted from BIM authoring tools or coordination platforms at handover. Required deliverable on many public sector projects.

.dwg — AutoCAD Drawing File (legacy bridge)

Originally a CAD format, but widely used as a 2D documentation deliverable from BIM workflows. Most BIM authoring tools export construction documents to DWG. Not a BIM format itself: a DWG carries lines, layers, and text, not parametric objects or property data.

.gbxml — Green Building XML

XML schema for exchanging building geometry and energy analysis data between BIM authoring tools and energy modeling software (IES Virtual Environment, EnergyPlus, OpenStudio). Used in sustainability and performance analysis workflows.

Software-to-format compatibility matrix

Software Authoring Format IFC Import IFC Export BCF COBie
Autodesk Revit .rvt Yes Yes Plugin Plugin
Graphisoft ArchiCAD .pln Yes Yes Native Native
Bentley AECOsim .dgn Yes Yes Yes Yes
Vectorworks Architect .vwx Yes Yes Yes Limited
Tekla Structures .db1 Yes Yes Yes Limited
Allplan .ndw Yes Yes Yes Limited
Autodesk Navisworks .nwf / .nwd / .nwc Yes Limited Yes No
Solibri Office (reads IFC) Yes No Native Native
ACC Model Coordination (cloud) Yes No Native Limited

Workflow patterns

Pattern 1: Single-tool team, single-discipline project

Authoring in native format (.rvt or .pln). No IFC needed for internal coordination. IFC and COBie exported only for client deliverables and archival.

Pattern 2: Multi-tool team, federated coordination

Each discipline authors in their native format. IFC exports at regular coordination intervals (typically weekly). Federation in Navisworks or Solibri. Issues routed via BCF. Final deliverable as IFC plus COBie.

Pattern 3: ISO 19650 / public sector contract

Client provides an IDS file defining the information requirements. Models validated against the IDS at each milestone. Deliverables packaged as IFC plus BCF plus COBie. CDE (Common Data Environment) governs file exchange between parties.

Pattern 4: Scan to BIM

Source data is a point cloud (.e57, .rcp, .rcs, .pts). Registration and processing in Recap, Cyclone, or similar. Modeling in Revit, ArchiCAD, or equivalent, outputting native format. Client deliverable typically IFC plus a registered point cloud reference.

Practical notes

Reference: https://vibimglobal.com/blog/what-is-a-bim-file/

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