Version 2.47.0 Free for all of us, forever.
The IFCtoLBD converter transforms Industry Foundation Classes (IFC) files in STEP format into Resource Description Framework (RDF) triples. These RDF triples adhere to the ontologies created by the World Wide Web Consortium (W3C) Linked Building Data Community Group (W3C LBD-CG: https://github.com/w3c-lbd-cg/).
Full documentation can be found here.
Jyrki Oraskari, Mathias Bonduel, Kris McGlinn, Anna Wagner, Pieter Pauwels, Ville Kukkonen, Simon Steyskaland, Joel Lehtonen, Maxime Lefrançois, and Lewis John McGibbney. Thanks also to Vladimir Alexiev and Kathrin Dentler for their valuable comments.
This project is released under the open source Apache License, Version 2.0
@misc{jyrki\_oraskari\_2026\_02,
author = {Jyrki Oraskari and
Mathias Bonduel and
Kris McGlinn and
Pieter Pauwels and
Freddy Priyatna and
Anna Wagner and
Ville Kukkonen and
Simon Steyskaland and
Joel Lehtonen and
Maxime Lefrançois },
title = {{IFCtoLBD v 2.46.3}},
month = aug,
year = 2026,
publisher = {GitHub},
version = {2.47.0},
url = {https://github.com/jyrkioraskari/IFCtoLBD}
}
New projects
When the geometry is exported, the material information as MTL is now included.
inst:wall_9808fd7f-dc48-478e-9217-628e833d7d12_geometry
<https://lbd.org/#asMTL_alpha> "1.0"^^<http://www.w3.org/2001/XMLSchema#double>;
<https://lbd.org/#asMTL_ks> "#000000";
<https://lbd.org/#asMTL_kd> "#808080";
<https://lbd.org/#asMTL_ka> "#808080";
<https://lbd.org/#asMTL> "newmtl material_0\nKa 0.501961 0.501961 0.501961\nKd 0.501961 0.501961 0.501961\nKs 0.000000 0.000000 0.000000\nd 1.000000\nillum 2\n\n";
lbd:hasBoundingBox inst:wall_9808fd7f-dc48-478e-9217-628e833d7d12_geometry_bb;
rdf:type geo:Geometry .
First version of recursive IfcComplexProperty and IfcPhysicalComplexQuantity.
GraalVM compilation for IFCtoLBD command line for Windows 11.
- Install GraalVM for JDK 21 and set GRAALVM_HOME to point to that directory
- Install Visual Studio Build Tools 2026 with the setting of Desktop development with C++.
- install Maven and add that to the system path.
At the project folder:
cd ./IFCtiLBD
mvn clean -Pnative -DskipTests package
Support for the new Apache Jena version 6.0.0. This means also that the oldest supported Java version is now 21.
The new version introduces a significant change: the converter now relies on a TDB database. While this makes it slightly slower, it enables the conversion of substantially larger IFC models.
- If you have a pretty large IFC model, the new version used disk space to convert it. There should be a proper error message about it now.
Added a small example in the Scala language. It depends on the maven compilation of the Java code shown above.
A small LLM example was added in Python.
A short example to list properties by elements was added. here .
I wrote a Python program to demonstrate how the interfaces can be used to infer which door to use to enter a space. 
The short example code can be found here.
While it’s still in the preliminary stages and requires thorough testing, a source code for our bounding box-based interface generation is now available. The code quality is being tested, and we are gearing up for the next pre-compiled release soon. If you encounter any bugs, please let me know.
Just in case you have a path problem in a MacBook when writing Python: -- It is recommended yo use absolute path names for the Java library files (macOS). You can use a text editor Search&Replace to fix there ysour configuration at the line of code: jpype.startJVM(classpath = ['...']).
A short example code of relative names can be found here.
The Python examples were rewritten so that the import error in some JPype versions should not appear. Also, instructions to copy the jars folder was added.
2D linegraph splits from the model  The short example code can be found here.
The same with doors and windows, and, finally, spaces.
Simple graph plot with Python. Source code is here . 
Python visualization demo code available here . 
The recommendations was changed to encourage to use one of the last two performant Long-Term Support version of Java (17 or 21).
The new user Java 17 (and above) compatible OpenAPI is now in the source code. Earlier Java versions are not supported as the current Enuciate package has that limitation.
The new user interface is in the testing phase. This is not the final version yet. I still test how the filtering can be made smarter.
 (updated 21st Feb, 2024).
Tested and update the Python interface.
The geometry tests are finished. The converter now exports OBJ formatted geometry for the building elements. The ifcZip format support is implemented but needs still some more testing.
Support for xsd:decimal.
Support for multi-character Unicode sequences.
Added unlinked elements and those that have no LBD type. It allows using the converter when there are no BOT elements connected to the interested in elements.
The Windows executable bundle for the Open JDK was fixed to contain the Java version.
Last Sunday the software was patched to contain Log4J version 2.15 and today version 2.16 was added. The OpenAPI installation was shortly tested under Apache Tomcat 9.0.54 and updated to the current IFCtoLBD release. The Docker image is also updated.
Example usage: java -jar IFCtoLBD_Java_15.jar http://lbd.example.com/ c:\IFC\Duplex_A_20110505.ifc c:\IFC\Duplex_A_20110505.ttl
The Unicode notation of the degree sign character caused Jena to stop reading the raw ifcOWL output. This is fixed now.
Java 8 is more than seven years old now, which means that not all libraries are supporting that old Java variant anymore. To keep the software secure, it is preferred to deprecate the version of the code in the long run. Currently, a separate Java 8 branch is kept in case only Java 8 can be used.
The program code was modified so that the default backslash notation for UTF-8 characters is removed. äÄöÖåÅßüÜáÁàÀâ should be human-readable.
The software was tested to function with https://jdk.java.net/15/
Testing the correctness of the created bounding boxes.
-
What does it mean when IFCtoLBD says “Java heap space”?
- This error typically occurs when converting a large file. It indicates the program has run out of memory allocated for the Java heap. To resolve this, try starting the program using run.bat
-
Why does the program say: "Error: Cannot determine which IFC version the model it is: [IFC2X2_FINAL]"
- IFC 2x2 Final was published as early as 2003, 14 years ago. There are still some test files that are generated using this version. Support for this may be added. Currently, the supported IFC versions are IFC2x3TC1, FC2x3FINAL, IFC4, IFC4 ADD1, and IFC4 ADD2.
-
Nothing happens when I start the program.
- Check that Java 15 is installed, open a command prompt, from the releases list, and download the precompiled
binaries, then at the directory where IFCtoLBD-Desktop_Java_15.ja is located. Run the following command:
java -jar IFCtoLBD-Desktop\_Java\_15.jar - If any further problems, under the Windows 10 operating system, you can also try to use the the bundled version of the converter: IFCtoLBD_Java15.exe
- Check that Java 15 is installed, open a command prompt, from the releases list, and download the precompiled
binaries, then at the directory where IFCtoLBD-Desktop_Java_15.ja is located. Run the following command:
-
I have a problem running the OpenAPI interface under Apache Tomcat 9:
- Check that the JAVA_HOME environmental variable at your computer points to Java version 15 or newer. The older versions of Java are not supported anymore (If you must use it for some reason, an older release of the converter can be used), since the used libraries don't support them anymore.
-
In Windows, I cannot open the program by double-clicking the file
- Open a command prompt as admin
- Run the following commands:
assoc .jar=jarfile
type jarfile="your java installation directory\\bin\\javaw.exe" -jar "%1" %\*
where your java installation directory is the base directory where your Java runtime is installed.
- How to disable the missing project natures in Eclipse prompt
- open Eclipse.
- go to Window > Preferences.
- navigate to General > Project Natures. There, you can disable the option for discovering missing project natures and marketplace entries.
-
Eclipse build takes forever to complete
- Disable Project/Build Automatically, and build the all with Maven Install. Enable the option after.
- eclipse -clean -clearPersistedState // It resets Eclipse perspectives, too.
The research was partly funded by the EU through the H2020 project BIM4REN.