How to Export Revit Phases to IFC: A Complete Guide for BIM Professionals

Introduction

Working with phases in Revit is essential for renovation, demolition, and multi-stage construction projects. Phases allow you to model existing conditions, demolition scopes, and new construction within a single Revit file. But when it comes time to share that model with consultants, contractors, or coordination platforms through IFC (Industry Foundation Classes), things get tricky.

Revit’s IFC export has a fundamental limitation: only one phase can be exported at a time. There is no built-in toggle to export all phases simultaneously or to tag elements with their phase status in a standard IFC property. This creates real challenges for project teams who rely on openBIM workflows and need phase-specific deliverables.

This guide walks you through everything you need to know about exporting Revit phases to IFC - from understanding how Revit handles phase data during export, to practical workarounds for demolished elements, custom property sets for preserving phase metadata, and coordination strategies using version comparison on platforms like Autodesk Docs.

Understanding Revit Phases and IFC Export Basics

Before diving into export workflows, it helps to understand how Revit’s phase system maps (or fails to map) to the IFC schema.

How Revit Phases Work

In Revit, every element has two phase-related properties:

• Phase Created - the phase in which the element was first added to the model
• Phase Demolished - the phase in which the element is marked for demolition (if applicable)

Revit uses Phase Filters to control which elements are visible in a given view. A typical project might have phases like “Existing,” “Demolition,” and “New Construction,” with views configured to show the appropriate elements for each stage.

What Happens During IFC Export

When you export a Revit model to IFC, the export respects the active view’s phase and phase filter settings. This means:

1. Only elements that are visible in the current view (based on its phase filter) will be included in the IFC file
2. Elements that exist in the selected phase are exported with their full geometry and properties
3. Demolished or removed elements are not exported - even if they existed in an earlier phase

This behavior is by design. The IFC schema does not have a native equivalent to Revit’s phase filter system. While IFC does support classification and property sets, there is no standardized way to represent “this wall was demolished in Phase 2” using core IFC entities alone.

Step-by-Step: Exporting a Single Phase to IFC

Here is the basic workflow for exporting one phase from Revit to IFC.

Step 1: Set Up Your View

Create or select a 3D view that is configured with the correct phase settings:

1. Open or create a 3D view in Revit
2. In the Properties panel, set the Phase to the target phase (e.g., “Existing” or “New Construction”)
3. Set the Phase Filter to control visibility. Common options include:
   • Show All - displays elements from all phases
   • Show Complete - shows elements as they would appear at the end of that phase
   • Show Previous + New - shows existing elements plus newly created ones
4. Verify that the view displays exactly the elements you want in the IFC export

Step 2: Configure IFC Export Settings

Navigate to File > Export > IFC and configure your export:

1. Choose your IFC version (IFC 2x3 Coordination View 2.0 or IFC4 Reference View are the most common)
2. Under the General tab, ensure “Export only elements visible in view” is selected
3. Under the Property Sets tab, decide whether to include Revit property sets, IFC common property sets, or both
4. Set the Phase to Export dropdown to match your target phase

Step 3: Export and Verify

1. Click Export and save the IFC file with a descriptive name that includes the phase (e.g., ProjectName_Phase-Existing.ifc)
2. Open the exported IFC in a viewer like BIM Vision, Solibri, or BIMcollab ZOOM to verify the correct elements are included
3. Check that element counts and geometry match your expectations

Important Note on Phase Building

Because phases in Revit build on each other, exporting a later phase (like “New Construction”) will include all elements that exist at that point - both the surviving elements from earlier phases and the newly created elements. Only demolished elements are excluded.

Handling Demolished Elements in IFC Export

One of the biggest pain points is that demolished elements cannot be directly exported to IFC. If you need to communicate demolition scope through IFC, you need a workaround.

Workaround 1: Export the Phase Before Demolition

Export the phase that contains the elements before they are demolished. For example:

1. Export the “Existing” phase - this IFC file contains all elements including those slated for demolition
2. Export the “New Construction” phase - this IFC file shows the project after demolition, with new elements added
3. The difference between the two files represents the demolition scope

This approach works well with coordination platforms that support model comparison or versioning.

Workaround 2: Use a Dedicated Demolition View

Create a view that isolates only the elements being demolished:

1. Create a new 3D view
2. Set its Phase to the demolition phase
3. Apply a Phase Filter that shows only demolished elements (you may need to create a custom phase filter for this)
4. Export this view to IFC separately
5. Name the file clearly (e.g., ProjectName_Demolition-Scope.ifc)

Workaround 3: Color-Code Demolished Elements

If your coordination platform supports color overrides:

1. In your Revit view, use Filters or Override Graphics to color demolished elements differently (e.g., red)
2. Export with material/color information preserved
3. Recipients can visually identify demolition scope in their IFC viewer

This is less precise than the other methods but can be effective for quick visual coordination.

Preserving Phase Information with Custom Property Sets

Standard IFC properties do not include phase data from Revit. If you need phase information to travel with your IFC export - for example, so that a BIM coordinator can filter by phase in an IFC viewer - you need to use custom property sets.

Creating a Custom Property Set for Phase Data

Revit’s IFC exporter allows you to define custom property sets that map Revit parameters to IFC properties. Here is how to set this up:

1. Create a shared parameter in Revit for phase information (or use the built-in “Phase Created” and “Phase Demolished” parameters)
2. Create a Property Set Definition file (a text file with .txt extension) that maps these parameters to IFC property sets

The property set definition file follows this format:

PropertySet: Pset_PhaseInformation  I   IfcElement
    PhaseCreated    Text    Phase Created
    PhaseDemolished Text    Phase Demolished

Each line after the header defines:

• Property name in IFC (e.g., PhaseCreated)
• Data type (Text, Integer, Real, Boolean)
• Revit parameter name to map from

Loading the Custom Property Set

1. In the IFC Export dialog, go to the Property Sets tab
2. Check “Export user defined property sets”
3. Browse to your .txt definition file
4. Export as normal

After export, every element in the IFC file will carry a Pset_PhaseInformation property set with PhaseCreated and PhaseDemolished values. BIM coordinators can then filter, query, or color-code elements by phase in any IFC viewer that supports property-based filtering.

Verifying Custom Properties in an IFC Viewer

After export, open the IFC file in a viewer and inspect an element’s properties:

1. Select any element in the model
2. Look for the Pset_PhaseInformation property set in the element’s property panel
3. Verify that PhaseCreated shows the correct phase name
4. Verify that PhaseDemolished shows the demolition phase (or is empty for non-demolished elements)

Multi-Phase Coordination Using Version Comparison

For projects with multiple phases, one of the most effective coordination strategies is version comparison on a common data environment (CDE) like Autodesk Docs, BIM 360, or Trimble Connect.

The Version Comparison Workflow

This workflow leverages the fact that CDEs maintain version history for uploaded files:

1. Export Phase 1 (e.g., Existing Conditions) to IFC
2. Upload the IFC file to your CDE with a consistent filename (e.g., Architecture_Phased-Model.ifc)
3. Export Phase 2 (e.g., New Construction) to IFC using the same filename
4. Upload again - the CDE overwrites the file but preserves the previous version in its version history
5. Use the CDE’s comparison tools to visualize differences between versions

What Version Comparison Reveals

When you compare the two versions, the CDE highlights:

• Added elements (new construction) - typically shown in green
• Removed elements (demolished) - typically shown in red
• Modified elements (relocated or resized) - typically shown in yellow
• Unchanged elements - shown in their original color or hidden

This gives project stakeholders a clear visual representation of what changes between phases without requiring any special IFC phase support.

Best Practices for Version-Based Phase Coordination

• Use consistent filenames across all phase exports so the CDE recognizes them as versions of the same file
• Document your phase export sequence so team members know which version corresponds to which phase
• Export phases in chronological order to make the version timeline logical
• Include a phase identifier in the file description (not the filename) for additional clarity

Common Mistakes and Pitfalls

Exporting phases to IFC seems straightforward, but several common mistakes can cause coordination issues.

Mistake 1: Forgetting to Check the Active View’s Phase

The IFC exporter uses the active view’s phase settings. If you forget to switch to the correct view before exporting, you will get the wrong set of elements. Always verify your view’s Phase and Phase Filter before starting the export.

Mistake 2: Expecting IFC Viewers to Handle Phase Filters

IFC viewers do not have Revit-style phase filtering. If you export a view with “Show All” as the phase filter, every element from every phase will appear in the IFC file with no way to distinguish them - unless you have added custom property sets for phase data.

Mistake 3: Using Inconsistent Export Settings

When exporting multiple phases for comparison, use identical IFC export settings (version, coordinate system, property sets) for every export. Inconsistent settings can cause alignment issues or missing data in your comparison.

Mistake 4: Not Testing with Your Coordination Platform

Different IFC viewers and CDEs handle version comparison differently. Test your workflow with a small model before committing to it for a full project. Verify that your platform correctly identifies added, removed, and modified elements.

Mistake 5: Ignoring Localization Differences

If your team works across regions, be aware that Revit localizes phase-related property names. For example, German-language Revit uses “Phase erstellt” (Phase Created) and “Phase abgebrochen” (Phase Demolished). Custom property set definitions must match the localized parameter names in each user’s Revit installation, or the mapping will fail silently.

Best Practices for Phase-to-IFC Workflows

Based on real-world project experience, here are concrete recommendations for managing phase exports.

1. Establish a Phase Export Plan Early

Before the project starts, document which phases will be exported, how often, and in what format. Share this plan with all discipline leads so everyone follows the same workflow.

2. Create Dedicated Export Views

Do not reuse working views for IFC export. Create dedicated 3D views named clearly (e.g., 3D_IFC-Export_Phase-Existing, 3D_IFC-Export_Phase-NewConstruction) with locked phase settings.

3. Automate with Dynamo or the Revit API

For projects with many phases or frequent exports, consider automating the export process:

• Dynamo scripts can iterate through phases, switch views, and trigger IFC exports
• The Revit API (Document.Export method) provides full programmatic control over IFC export settings
• Automation reduces human error and ensures consistency across exports

4. Include Phase Metadata via Custom Property Sets

Always export custom property sets with phase information. Even if your current workflow does not require it, having phase metadata embedded in the IFC file future-proofs your deliverables.

5. Use a Naming Convention That Scales

Adopt a file naming convention that includes the project name, discipline, phase, and date:

PROJ-ARCH-Phase01-Existing-20260325.ifc
PROJ-ARCH-Phase02-Demolition-20260325.ifc
PROJ-ARCH-Phase03-NewConstruction-20260325.ifc

6. Validate Every Export

After each export, open the IFC in a lightweight viewer and run these checks:

• Element count matches expectations
• Geometry is correct (no missing or extra elements)
• Custom property sets are populated
• Coordinate system is consistent with other discipline models

7. Document Your Workflow

Write a brief guide for your project team that covers the export settings, naming conventions, upload procedures, and verification steps. This prevents inconsistencies when multiple team members are involved.

IFC4 and Future Improvements

The IFC schema continues to evolve, and future versions may offer better support for phased construction data.

IFC4 Improvements

IFC4 introduced several features relevant to phased projects:

• IfcTask and IfcWorkSchedule entities can represent construction sequences
• IfcRelSequence can define dependencies between construction activities
• Improved property set definitions allow richer metadata

However, most practical BIM coordination still relies on IFC 2x3 or IFC4 Reference View, and native phase support remains limited.

What to Watch For

The buildingSMART organization is actively working on:

• IFC4.3 with improved infrastructure and phasing support
• Better integration between IFC models and construction scheduling (4D BIM)
• Standardized property sets for renovation and phasing workflows

Until these improvements are widely adopted, the workarounds described in this guide remain the most reliable approach.

Conclusion

Exporting Revit phases to IFC requires understanding a key limitation: only one phase exports at a time, and demolished elements are excluded. But with the right workflow - dedicated export views, custom property sets for phase metadata, and version comparison on your CDE - you can deliver phase-accurate IFC models that support effective multi-discipline coordination.

The most important takeaway is to plan your phase export strategy early and test it with your specific coordination platform before the project ramps up. Custom property sets are your best tool for preserving phase data in IFC, and version comparison is the most practical way to communicate demolition and construction scopes to your project team.

If you are working on phased renovation or construction projects and want to deepen your Revit and BIM skills, explore the courses available at Archgyan Academy for hands-on training in Revit workflows, IFC interoperability, and BIM coordination.