GDL logo on white bgAt the core of ArchiCAD objects lies the GDL parametric programming language. Through GDL programming, developers can produce smart parametric objects. The result are library objects that can be scripted to adapt and change according to suit the context where they are implemented.

Why GDL?

One of the main reasons that we love using ArchiCAD is that GDL offers unparalleled intelligence while maintaining a very small file size. Unlike other competing BIM platforms, GDL offers nearly unlimited potential to customize an object’s configuration. For example, a single door object can have any number of styles to select from, whether it be glazed, partially glazed, solid, traditional, contemporary, etc. Of course, dimensions and material finishes are all customizable. Furthermore, GDL can recognize the wall construction into which the door is being inserted so that the frame fits properly, whether it be an interior stud wall or an exterior cavity wall.

The power of GDL is only limited by the developer’s knowledge and understanding of the end user’s needs. In this way, it is much like architectural design.

CadCentre offers the development of customized objects to suit its client’s specific requirements. Those objects could be specialty equipment, prefabricated blocks, furniture, or any other ArchiCAD object. We propose our services for GDL development worldwide.

If you need customized, native, fully parametric, GDL-based ArchiCAD objects, that would improve your workflow, let us sit down with you, for a remote meeting and we can evaluate, analyze your needs. At the end of this meeting, you will have a better understanding of the end result and an estimation for our services. (a form will be inserted in the page, to contact us on the subject).

EBK 1K sqMeet our Senior Developer

In charge of GDL development for CadCentre is Evangelo Kalmantis M Arch, OAA, MRAIC, NCARB, LEED-AP BD+C. His extensive experience in both Architecture and GDL development, will allow him to understand the needs and requirements of the client, and consequently, develop the highest quality of native parametric ArchiCAD objects.

Evangelo Kalmantis is an architect with more than 26 years of experience in using ARCHICAD. Shortly after becoming licensed, he searched for the right tools to enable him to build a practice that would leverage his office’s abilities to promote, design, and produce projects. Evangelo realized that computer technology, which was fairly new to the architectural profession at the time, had the potential to transform the design industry.

Beginning with version 4.55, Evangelo trained himself on using ARCHICAD and completed several smaller projects with it. As he became more proficient, he realized that the application had much more potential than he could harness from its suite of tools. He realized that to access this potential, he needed to learn GDL.

Over the years, Evangelo has developed many objects that have supplemented his library and have helped him to model exactly what he needs. He has continually updated his GDL skills in order to keep up with ARCHICAD’s development. With his knowledge of building science as well as LEED design principles, Evangelo has been able to mine intelligent information from ARCHICAD to optimize the energy efficiency of his projects. He realized that GDL was more than a 3D modelling tool so he turned his attention to creating calculation tools.
Evangelo has sold many of his objects to over 24 countries around the world. His approach to designing GDL objects is founded on three principles:
• Parametrize where appropriate to maximize customization within realistic bounds,
• Reduce the size of an object while maintaining its appearance, and
• Provide an intuitive graphic user interface to organize the selection of variables.

Interested in Custom Objects?

Fill up this form and we will contact you at the earliest and set a remote meeting and evaluate your needs.


Examples of our work

Here are some of the objects that Evangelo developped through the years.

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This dynamic arched linel allows you to change its properties within the 3D Window.


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This machine provides magnetic resonance (MR) images at the same time as the radiation beam is being delivered.

The Elekta and Varian Linac (linear accelerator) objects were developed for a cancer clinic project. Having the manufacturer’s drawings on hand, Evangelo created the objects based on dimensioned drawings and specifications to ensure accuracy. The intelligence available through GDL scripting enabled Evangelo to add controls for component movement within the limits specified. The Varian model was selected for the project and he enhanced the object to incorporate the radiation field for design visualization purposes. As the field is actually invisible, I added a visibility toggle. This enabled him to visualize the radiation field on demand as the arm rotates around the bed. Like everything else in ArchiCAD, what is seen in the 3D window is also visible in plan, elevation and section views.


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M1 2D 2

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The ladder objects adjusts its parameters when the ladder gets stretched up.

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ladder 2

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