BricsCAD BIM Data Structure Explained

Quick answer: A BIM Project can be a single DWG file or several. A single file embeds its own project database directly. Multiple files instead share an external .bsyslib project database file, while each DWG also keeps its own internal copy for local, interference-free work, synchronized whenever you save.

The Project Database

Single DWG file: the file contains the complete BIM Project, with the project database embedded directly inside it.

Multiple DWG files: the project database is stored externally as a .bsyslib file, shared across every DWG in the project. This holds project-level data like spatial locations, property definitions, and compositions, read directly by each DWG. Every DWG file also keeps an embedded internal copy of that external file, used while you’re actively working on it, letting each user work locally without interfering with others.

Only when you save does BricsCAD synchronize: pushing your changes to the internal copy, then pulling in whatever changes other project members made in the meantime, so everyone with access ends up seeing the same updated information.

Saving locks the external BSYSLIB file, so two users can’t save to it simultaneously. If two users happen to change the same data, BricsCAD keeps the most recent change and notifies whoever’s work got overwritten.

DWG entities classified as Building Elements can have Compositions attached, and every Composition used in a project is stored in that project’s database.

The Central Database

To reuse compositions and materials across multiple BIM Projects, specify a Central database, another BSYSLIB file, usually stored somewhere common to several projects. Compositions and Building Materials used from it import automatically into the project database, and you can drag items between databases (provided you have write access to the destination) to maintain and extend them.

Sample databases install into the Support subfolder of the Roamable root folder, the same location covered on this hub’s user files page. When you install a BricsCAD update, the User File Manager, also covered on that page, prompts whether to overwrite them, so it’s recommended to rename your own central databases or save them elsewhere. Set the central database location in the Central Database tab of the BIM Project Info dialog.

Materials and Compositions

A BIM database consists of Building Materials and Compositions. A Building Material describes one specific material, its appearance, cost, manufacturer, and similar details. A Composition describes a building element’s structure through an ordered set of composition layers, each referencing a Building Material and carrying its own thickness.

Flexibility in Attaching Compositions

The same flexibility available in modeling extends to attaching building information. Compositions group into Wall, Slab, Roof, and Generic categories, but any type can attach to any DWG entity regardless. Attached to a 3D solid with the right geometric properties, a composition’s thickness defines the resulting wall or slab thickness, and its cross-section shows the layered structure using each layer’s hatch pattern. If a composition with a fixed or minimal thickness can’t actually be applied to the solid’s geometry, the section displays in red, confirming exactly the same incompatibility indicator covered on this hub’s BIM entity selection page.

All of this is accessible from the dockable BIM Compositions panel.

Composition Layer Fields

Each composition layer has three fields:

• Pattern and Material Name: the Building Material assigned to that layer.
• Function: None, Structure, Substrate, Insulation, Finish1, Finish2, or Membrane, currently informational only.
• Thickness: the layer’s thickness.

Frequently Asked Questions

What happens if two people edit the same BIM project data at the same time? BricsCAD keeps whichever change was made most recently and notifies the person whose work got overwritten.

Why does a Composition sometimes appear in red on a section view? Its thickness (fixed or minimal) can’t actually be applied to the solid’s current geometry, indicating an incompatibility.

Where should I store my own central database to avoid it being overwritten by updates? Rename it, or save it somewhere other than the default Support subfolder, since BricsCAD’s update process may prompt to overwrite the sample databases there.

Can a single project database hold spatial locations and property definitions too, not just compositions? Yes, all of that project-level data lives in the same shared database, whether embedded in a single DWG or stored externally for multiple DWGs.