GDL is a powerful Tool towards Building Simulation.
GDL Building Objects are Containers
for Geometry and Attribute Information.
- GDL stands for "Geometric Description Language" and is a scriptable language similar to BASIC. It is an open system that allows anybody (see also "Making Tea") to build "virtual" objects which can be used in a large variety of Computer Aided Design (CAD) environments.
- A GDL Object can store 3D information (geometry, appearance, surface, material, quantity, construction etc.), 2D information (plan representation, minimal space requirements, labels etc.), and property information (serial numbers, price, dealer information, url, and any other kind of database information)
- A GDL Object can describe real building components, like doors, windows, walls, roofs, furniture, plumbing fixtures, HVAC systems, structural elements etc.
- These Building Components can behave smart, i.e. they can adapt to changing conditions. The user can easily customize them through an interface to meet his needs.
- As opposed to symbols and 3D representations of objects that are static (none or little customizing possible), the objects "described" with GDL use only a fraction of memory of other modelled objects and carry much more information. This is especially important as the Internet emerges as the best communication platform for the building industry.
- The parametrics in GDL mean that a whole manufacturer series of a part can be packed into one object. The specific model needed by the user can be chosen within the list of parameters: Plan, Section, 3D-View and Database output are updated with that one change in the parameters list. Multiple instances of the same object but with different appearance, material, size etc. are kept together in one object.
There are essentially two different types of GDL objects:
- The first one is a highly parametric building element which is used in a general way to explore design and when using customizable objects.
See Generic Window Example
- The other is a brand specific object produced by a building component manufacturer containing all the variations of the object including the brand specific information in 2D, 3D and database information. See Pella Window Example
For more information, visit GDL Technologies Website at
A good introductory presentation (relatively small flash file) can be found at