IFC to DWG Conversion: Methods and Best Practices

IFC to DWG Conversion: Methods and Best Practices

Construction teams often receive BIM models in IFC format but need DWG files for CAD-based review, drawing preparation, and coordination with contractors and subcontractors. Converting IFC to DWG can help bring model geometry into a familiar CAD environment, but the conversion process does not always produce drawings that are ready for construction use.

Depending on the source model and conversion method, teams may need to check missing geometry, incorrect units, model positioning, and the availability of BIM component properties. Additional drafting may also be required to turn the converted model into usable 2D construction drawings.

This guide explains three ways to convert IFC to DWG using BIM-compatible CAD software, Revit, or online conversion tools. It also covers common conversion issues and practical checks to help construction teams prepare the resulting DWG files for downstream workflows.

What Is an IFC File?

IFC, or Industry Foundation Classes, is an open BIM data exchange standard designed to help different software applications share information about building and infrastructure projects.

An IFC file can contain 3D geometry for building components, along with component categories, materials, and other related properties. The information available depends on the source model and its export settings.

By converting IFC to DWG, project teams can review and organize model geometry in a CAD environment according to their needs and continue with downstream drafting tasks.If your source model is in Revit's RVT format instead, see our guide to RVT to DWG conversion.

How to Convert IFC to DWG

Depending on the software available, file requirements, and project workflow, you can choose from three common methods.

Method 1. Using BIM-Compatible CAD Software

If you need to bring an IFC model into a CAD environment for model review and further drafting, choose CAD software that supports IFC import. ZWCAD supports importing IFC models for 3D model inspection and access to available component information, helping construction teams review building elements and continue with CAD drafting in the same environment.

The general workflow for converting IFC to DWG in ZWCAD is as follows:

1. Import the IFC file. Open a compatible version of ZWCAD and use the supported IFC import command or menu option to import the source model.

   

2. Explore the imported model. Use the model view to inspect the overall structure and identify the floors, walls, doors, windows, or other components relevant to your task. Use the IFC Structure Panel to navigate the component hierarchy and view available properties.

   

3. Check the information available for review. Inspect component properties to identify the information relevant to your project. Use data extraction tools to retrieve relevant model information, and add 3D objects as IFC components when needed for further model development and coordination.

4. Save the drawing as DWG. Use the supported Save As workflow to save the imported drawing in DWG format, specifying the file name and destination.

5. Verify the DWG output. Reopen the saved file and check that the required geometry and drawing content are displayed correctly. If the file will be used for further drafting, determine whether additional geometry, dimensions, annotations, or drawing templates are needed.

   

Method 2. Convert IFC to DWG Using Revit

If your project team already uses Revit, you can import or link an IFC model, prepare the required views, and export them to DWG. This method works well when you need specific floor plans, sections, elevations, or drawing layouts for CAD-based documentation.

Basic workflow:

1. Open the IFC model. Import or link the IFC file using a supported Revit workflow.

2. Prepare the required views. Select or create the views and sheets needed for the project.

3. Configure the export settings. Go to File > Export > CAD Formats > DWG and review settings such as layer mapping and units.

4. Export and check the DWG files. Select the views or sheets to export, then open the resulting files in CAD software to verify geometry, scale, layers, and annotations.

   

Source: https://forums.autodesk.com/t5/community-blog-aec-english/using-layer-modifiers-for-a-more-accurate-dwg-export-in-revit/ba-p/13031440

Revit exports selected views or sheets; it does not automatically create a complete, fully editable DWG equivalent of the original BIM model. Some BIM properties may not be retained, so check the output against your project requirements before using it for further drafting.

Method 3. Convert IFC to DWG Using an Online Converter

Online conversion tools provide another option for users who need to convert IFC files to DWG without installing additional desktop software. The following tools offer online IFC-to-DWG conversion services.

Innerscene IFC to DWG Converter

Innerscene offers a browser-based conversion workflow without account registration. Its website states that IFC files up to 200 MB can be opened directly, although the effective limit may depend on the available memory of the device.

The tool converts model surfaces into tessellated geometry, so the output may be suitable for reference, viewing, or basic CAD work but may not retain the original model's parametric structure. According to the provider, the source IFC is opened in the browser, while the generated geometry is sent to its service to produce the DWG file.

ConvertSharp IFC to DWG Converter

ConvertSharp provides another browser-based conversion option. Its website states that processing takes place locally in the browser rather than uploading files to a server. This may be worth considering when file privacy is a priority, but check the tool's current processing behavior and terms before using it for confidential project data.

The website does not clearly specify a maximum file size or provide a detailed breakdown of which geometry and BIM properties are retained in the output. Test the converter with a non-sensitive sample file first if you need to confirm whether its DWG output meets your requirements.

Which online converter should you choose?

Compare the maximum supported file size, processing method, geometry quality, and information retained in the DWG. Online tools may be convenient for simple conversions, but for large or complex models, project-critical geometry, or workflows that depend on BIM properties, use a compatible desktop application and verify the output before relying on it.

Common IFC to DWG Conversion Problems

Converting IFC to DWG can introduce issues with model geometry, dimensions, component information, and drawing performance. The results depend on the source model and the capabilities of the software used for conversion. Understanding these limitations can help construction teams avoid problems in subsequent CAD work.

Missing or Incomplete Model Geometry

Some building components may be missing or displayed differently after an IFC model is imported into CAD software. This can happen when the source IFC file lacks the expected elements, the import settings exclude certain content, or the software does not fully support the geometry involved.

Compare the imported model with the original IFC file to identify the affected components. If elements are missing, review the source model and available import settings before trying the import again. If the issue persists, consider using another compatible tool to determine whether the problem is specific to the conversion workflow.

Incorrect Scale, Units, or Model Position

A model that appears too large, too small, or far from the expected drawing area can cause problems with measurements and drafting. Differences in drawing units, coordinate settings, or the source model's origin may account for these issues.

Start by comparing the units used in the source model and the destination drawing. Measure a known dimension in both files to identify any scaling differences. If the model appears in an unexpected location, investigate its coordinate settings before moving or scaling the geometry, particularly when accurate positioning is important for construction coordination.

Missing BIM Properties or Component Information

A converted DWG may contain the model geometry without providing access to all the properties stored in the original IFC file. This is because geometry conversion and BIM data preservation are not necessarily the same process. The information available also depends on the source file and the software's IFC support.

If you need component names, categories, materials, or other properties, inspect the original IFC file in a compatible BIM viewer and compare the available information with what can be accessed in the CAD environment. Use the IFC Structure Panel to review available component information. Keep the original IFC file if you need to reference properties that are unavailable in the DWG.

Large DWG Files and Slow Performance

Complex IFC models can produce large DWG files that are difficult to navigate or edit, especially when the drawing contains more detail than the task requires.

ZWCAD offers fast IFC import and export, helping construction teams move between BIM models and CAD drawings more efficiently. This allows teams to spend less time waiting for file processing and more time reviewing model geometry and preparing drawings for downstream construction workflows.

To improve CAD performance, keep only the building elements needed for your project and remove unnecessary geometry from a copy of the DWG file. Organize the remaining elements into layers to make the drawing easier to navigate and edit. Keep the original file unchanged and check the revised DWG to ensure that all required geometry is preserved.

How to Prepare Converted DWG Files for Construction Workflows

A converted DWG should be treated as an input to the drawing workflow, not automatically as a finished construction deliverable. The next steps depend on whether the team needs to review a 3D model, extract component information, or prepare 2D drawings for site use.

Review the DWG Before Use

Before sharing a converted DWG with contractors, subcontractors, or other project teams, make sure the file is organized for its intended purpose.

• Drawing organization: Arrange layers and group related elements so other team members can locate and work with the required content.

• Project standards: Apply the relevant layer conventions, line types, text styles, and drawing templates used by the project.

• Drawing references: Confirm that dimensions, annotations, section references, and other drawing details are consistent with the intended deliverable.

• File handover: Use a clear file name and revision identifier, and confirm that the DWG opens correctly on the receiving system.

If the drawing will support quantity estimation, verify the model scope and the counting rules before using component counts in a bill of quantities. Quantities extracted from a model may require further review to account for duplicate elements, exclusions, and project-specific measurement requirements.

Prepare 2D Construction Drawings for Site Use

A converted IFC model can provide a starting point for preparing 2D construction drawings, such as floor plans, sections, elevations, and detail views. The work required depends on the source model and the information needed for the project.

A typical workflow includes:

1. Select the required views. Identify the floors, areas, sections, or components relevant to the construction task.

2. Prepare the 2D geometry. Use the available model geometry as a reference to create or refine the views required for the drawing.

3. Add construction details. Include dimensions, notes, symbols, leaders, and detail references as needed.

4. Apply drawing standards. Use the project's title block, layer conventions, text styles, and drawing template.

5. Review the drawings. Confirm that the geometry, annotations, scale, and references are clear and consistent with project requirements.

6. Complete the approval process. Check revisions and follow the project's review procedures before issuing drawings for construction.

With ZWCAD, teams can review imported IFC model content and continue with CAD drafting in the same environment. The amount of additional drafting depends on the required output and the information available in the imported model.For more guidance on how drawing preparation fits into the wider project process, read our guide to the BIM workflow in construction.

FAQs

Can AutoCAD Open IFC Files Directly?

Yes, but it depends on the AutoCAD product you use. Standard AutoCAD does not natively support direct IFC import, while AutoCAD Architecture and AutoCAD MEP provide built-in IFC import capabilities. Other options include using compatible BIM software or an IFC import add-in.

Can You Convert IFC to DWG Without Revit?

Yes. Revit is not the only option. You can use compatible CAD or BIM software that supports IFC import and DWG drawing workflows.

ZWCAD Professional Edition offers IFC import and export capabilities for model inspection and subsequent CAD work. Before choosing a conversion method, consider whether your project requires 3D model geometry, 2D drawing output, or access to component properties.

Can You Convert IFC to DWG for Free?

Some software and online tools offer free viewing or conversion options. Available formats, file-size limits, and export features vary by tool.

Before using an online converter, confirm that it supports both IFC input and DWG output. You should also review its data-handling terms when working with project files.

If you already have access to compatible CAD software, test its IFC import and DWG workflow to determine whether an additional conversion tool is necessary.

Conclusion

Converting IFC to DWG brings BIM model geometry into a CAD workflow for review, drawing organization, and further drafting. The best method depends on the source model, available software, and intended output.

Before using the resulting DWG in project work, review its geometry, units, model position, layers, and required drawing content. For teams looking to connect BIM model review with CAD drafting, ZWCAD offers an integrated environment for working with IFC models and preparing CAD drawings.