Automated validation for IFC building models

Chi Zang recieving the 'Best Phd paper' award at ECPPM 2014

Chi Zang recieving the ‘Best Phd paper’ award at ECPPM 2014

Chi Zang is a Phd student at the Eindhoven University of Technology. His researchtopic is about “Automated validation for IFC building models“. He published a paper about this topic at the ECPPM conference in Vienna (Austria) this month. He won the ‘Best phd Paper’-award during that conference.

In the development of this research he was using the platform. More information about his work can be found on youtube and slideshare, or find the pdf of the paper here.



1000 dollars for your IFC file?

dollarsAs you know, at we intent to build a stable and reliable foundation for other developers to build their tools on. We are very proud and quite confident about the work we released so far. Of course we never rest and keep testing on a constant base. We need the help of the users for that because we need IFC data to test our tools. That is why we created the bug bounty program. We are still not sure on how to shape that program, but decided to at least give a reward of 1000 dollars to anyone who provides us (in the next couple of months) with an IFC model that crashes the BIMserver platform.

Of course the IFC model you provide should be a valid IFC model. We have some known issues that we think are not affecting this challenge, but nonetheless those are excluded (just to be on the safe side). The challenge is to be conducted on the latest stable release of BIMserver (so not the IFC4 beta release). Needless to add that this is about BIMserver. Most users add IfcOpenShell, and other plugins to BIMserver. These plugins could cause issues, but obviously we are talking about just BIMserver here.

Please send the files to We understand that sending large files can be a problem, but tools like wetransfer and dropbox can help you with that.  We strongly encourage to share your models public under a creative commons license. In that case, please send a pull request to the IFC repository on github. That repository is used to test all tools of the open source BIM collective so every contribution is highly appreciated. We even appreciate it so much that we randomly draw a winner from the contributors to collect the 1000 dollars when nobody collects the money from the bug bounty. All contributors will get a coffee mug, a towel and our eternal gratitude.  People that add IFC4 models to the github repository will receive an extra surprise.





First release candidate version 1.2

bimserver logoWe have launched the first release candidate of the 1.2 version of the BIMserver platform. It is available on our development website at Google code.

Some of the new features include the ability to add non-IFC data to the database. Users can now add ‘extended data’ to revisions and projects. Not all data can be added. This is controlled by the server administrator. Every BIMserver administrator has to authorize data schemas first so users, or external services can add extended data according to an authorised schema.

As beta-testers already saw, there is a new plugin type called ‘query plugin’. Wiet Mazairac created a plugin for the open BIM Query Language ( which is included in the BIMserver build. We also added an ‘internal service’ plugin that lowers the threshold for developers to build custom BIMservers for a specific feature. The clash-detection feature is now an internal plugin that will trigger on every ‘new revision’.

A big change we are very enthusiastic about, is the ability to subscribe (link) to external services. External services are webservices that run on a separate server (could be closed source) that handle a specific feature. At this moment there are services that do clash-detection (and return a BCF file); make a 2D HTML floorplan; do logging (for KPI project analyses); and there is even an external service that sends out an e-mail to all project members when there is a BCF returned from a clash-detection service. An external service can be triggered at a ‘new revision‘ and ‘new extended data’. In the future these triggerpoints will include all BIMserver log actions (like new user, new project, user added to project, etc) and we are working on data specific changes triggers (trigger only when doors are changed, or when a specific object with GUID is changes). In practice BIMserver sends out a notification to the external service and includes a token for authorization and authentication. Users can edit the subscription to external services and give out very specific tokens and authorizations. A list of external services will be hosted on our new plugin directory The list is dynamically loaded from any running BIMserver so it will be up-to-date all the time.
At this moment only a few external services are on the list, but many are in the making. The BIMserver team will not make any external services, but encourages developers to do so. The interface between BIMserver and the services is build according to the open standard BIMSie. This means that external services can also interact with each other and are not specifically build for This way the BIMserver team tries to innovate the industry and stimulates actual working in a federated web service environment (in contrast to spending marketing budget to use the word ‘cloud’ as many times as possible).

The biggest change that end-users will notice is that there is no GUI included anymore. Any BIMserver that starts will get a configuration screen (to create an administrator, add smtp server, the usual stuff that was already in 1.1), but after that it will show the BIMserver logo with the status indicator ‘running’. This is a big change for all of us, but specially for end-users, that simply cannot use BIMserver out of the box. Yet we feel this is a necessary step we have to take. As our loyal followers know, BIMserver is an open platform to use and build on top. The GUI was always a reference implementation of ‘how a GUI could look like’. We always stimulated developers to build specific GUIs. Guys like BIM Surfer and bimsync did, but we hope more will follow. To accelerate the development of several different GUIs we decided to remove the one we made. With the 1.2RC1 release we invite developers to build as many new GUIs as you like. We think we made it a bit easier by adding a JSON protocol to the rich Service Interface. This might lower the threshold for Javascript developers to make a really cool looking GUI for BIMserver.

Wrapping up the 1.2 release of BIMserver is even more focused on positioning BIMserver as an open and stable platform for others to build on. BIMserver is becoming a platform more and more, and less a product ready for end-users. This is also why the 1.2 RC1 has two developer libraries in the download section.

We feel BIMserver has made some huge steps again. This time taking some risky decisions on the GUI part, but on the other hand innovating the industry again with the introduction of a staggering concept to easily link federated BIM services. This blogpost is an open invitation to all developers to reap the fruits and create your own product build on top of our platform.

Third release candidate for 1.1.0

bimserver logo Today we are proud to release the 3rd 1.1.0 release candidate for Some new bugs, found by the community, are fixed. This release also has the ‘clash detection’ feature working again (although it will be obsolete after 1.1.0 final). This version has a major update for the ObjectIDM configurations and is tested intensely in a multiuser environment. Please read the full 1.1.0 release notes in our previous blogpost.

Download the 1.1.0-RC3 on or on our development site

Second candidate for the 1.0 release

Some users found a few bugs in the first release candidate for version 1.0 of the open source BIMserver software. We fixed these issues and also did some additional work on the ‘intelligent merging’. You can test this new merging feature by selecting ‘intelligent merging’ in the settings screen. The merged models (project with subprojects) are now better merged than before. Feel free to try this version and send us feedback. Download it from

Integrated Clash detection

As you guys know, the BIMserver team works very close with the guys from TNO in the Netherlands. A year ago this resulted in a special client side IFC viewer with an ‘open from server’  button. In the 0.8 release we integrated the IFC Engine DLL that makes it possible for the BIMserver to export to CityGML, Collada, Google Earth, and more….

Today we announce a new feature of the BIMserver that is a result of our cooperation with TNO: integrated Clash detection!

The 0.9 release of the BIMserver will have the ability to check your model for clashes. This means you can check a submodel (two walls modelled by the architect clashing) or even the merged complete model (to check if a pipe that’s modelled by the HVAC modeller clashes with a wall that is modelled by the architect).

This feature is seen as a key feature for working with BIM. The open source BIMserver is proud to offer this feature to our users. We will keep you posted on the details and the release date. on FOSS4G2009

These days all the open source GIS nerds are attending the FOSS4G (Free and Open Source Software for Geospatial information) congress in Sydney Australia. Because the BIM world and the GIS world are starting to overlap each other, was also present at this conference. We made a contribution by presenting the CityGML extension for BIM and it’s implementation in For those of you who missed it you can find the sheets, the extension and some example files on

Update: find everything on


“IFC needs modernization”

The open geospatial consortium and the BuildingSMART alliance have put the results of a ‘testbed’ online. In the testbed the teams discovered that areas of the IFC model are not as amenable to interoperability as once thought, and modernization is believed necessary.

A quote from their press release:
“The teams discovered that areas of the IFC model are not amenable for interoperability as commonly defined and practiced by industrial communities that require collaboration [..]. The IFC structure, first developed in the 1970’s, can be modernized by the community so that a more complete suite of benefits from interoperability reaches critical mass and adoption in the market. With IFC modernization, a far more open, comprehensive and intelligent life-cycle data model of buildings can be achieved. IFC modernization working in parallel with highly efficient network-based communication, process management, decision-support and performance simulation of design alternatives is the sweet spot for achieving benefit in real industry projects..”

This is one of the first public notices from BuildingSMART stating that IFC can and should be modernized to fit the needs of today. Users of software that experience intense project collaboration have been one of the first to notice this issue in practice. At we believe that modernizing IFC would be to best way to fully profit from the modern possibilities of technology and to fully fit the needs of today’s users.
The development-team of is very aware of the current issues, but also hopeful about future possibilities. The modernization of IFC is on of the key-issues for our RnD team. is happy and proud to be on the front of innovation by developing technology that helps stretching possibilities of IFC and the AEC-industry.

More info about the testbed and the webcast can be found at this link.