The Little Bonsai Garden

This is a quick beginners guide for anybody adopting Bonsai BIM. Links to more comprehensive information, such as the Bonsai documentation, are given wherever possible. If you haven’t got it yet, start with the installation guide.

Bonsai turns Blender into an editor for IFC files. It runs on GNU/Linux, macOS and Windows, and it is Free Software.

IFC is the open standard file format for BIM: buildings modelled as data rather than drawn. The objects in the file carry their own properties and their relationships to each other, rather than being simply geometrical shapes. Drawings, schedules and quantities are generated out of the model rather than maintained by hand.

You should consider Bonsai when you need to:

Edit, enrich, or clean up IFC files.
Search, browse, or extract information from IFC files.
Author entire projects in the open BIM format for maximum compatibility and future-proofing.
Work collaboratively using a modern fork/merge workflow with Git version control.
Own the tools of your trade, rather than renting tools that could vanish at any time.

What is Bonsai?

Bonsai is an editor for IFC files. The .ifc file is the document. When you save, you write IFC; there is no export from a proprietary project format. There is no import either; you simply open the IFC file.

Bonsai bundles what you need for ordinary work: modelling, drawings, schedules, quantities and model checking are all part of the package, so there is no toolchain to assemble.

Bonsai is a Blender mod

Bonsai is distributed as a Blender add-on, but it is a bit more than an add-on: it replaces large parts of Blender’s interface, adds tools and panels of its own, and changes many familiar operations. With Bonsai enabled and a project open, you are working in a substantially different program.

Navigating the viewport, selecting objects and editing meshes behave as close to Blender’s defaults as possible, but lots of other things are very different. Which of your habits survive and which don’t has a page of its own.

Bonsai and IfcOpenShell

You can consider Bonsai as the graphical part of a larger project called IfcOpenShell. IfcOpenShell is the library that actually works with IFC and Bonsai is just one program built on it.

Many utilities that use IfcOpenShell ship with the Bonsai package. They matter later, when you want to automate something, process many files at once, or script a job that would be tedious by hand.

Bonsai is a mutual aid project

Bonsai is made by the people who use it. Somebody meets a problem on a real job, solves it, shares the solution, ready for whoever needs it next - created by people, for people.

This is what makes Bonsai yours: think of it as a tradesman’s tools that go with you between jobs and employers.

There is more on how Bonsai gets made: where help comes from, how to get involved, and how easy it is to go from using this software to changing it.

The file is the document: Bonsai saves IFC. There is no separate project format, so there is no import and no export.
Bonsai is a Blender mod: Bonsai replaces lots of Blender stuff; it is more than just an extra panel you can ignore.
The model is a graph: IFC describes objects and the relationships between them, in its own published vocabulary. Most objects in the file have no 3D geometry.
Containment - the spatial tree: Project, site, building, storey, space. Everything physical is assigned somewhere, or it isn't really in the model.
Decisions to settle when you start a project: Units, georeferencing and schema version belong to the project rather than to anything in it. Units and schema are set once and are awkward to change afterwards; georeferencing can wait, but it limits the schema.
Types and occurrences: How a wall type differs from a wall, where the Revit family analogy holds, and why there is no vendor content library.
Properties and materials: Attributes, property sets, quantities, material layers and classification systems. The data that isn't geometry.
Representations - alternative geometries: An object may have no geometry, one, or several. A plan symbol is a stored representation, not a picture generated on the fly.
Parametric geometry: What parametric means here, which objects are built from numbers and which are shapes you made, and which relationships are maintained.
Searching and queries: Selecting and filtering by data rather than by clicking, which is how you reach the parts of the model the viewport doesn't show.
Output: Drawings, schedules and quantities are generated from the model, and the annotation lives in the IFC file with everything else.
Checking the model: Two different questions - is this a valid IFC file, and does it contain what somebody asked for.
Editing received files: Bonsai opens any IFC file, not only its own. Correcting and enriching a file that another program exported, and what is left alone when you do.
Using other people's models: Linking and federating models, and BCF. Several models at one moment, and why there is no central model to check out of.
Revisions: The model is a file, so Git can track its history. One model across time, and several people working on it at once.
Scripting: Everything Bonsai does through a panel it will also do from a script. The standalone tools, the library underneath, and when automation earns its keep.
Tending Bonsai: Bonsai is built by the people who use it. Where help comes from, how to get involved, and why the step from using it to changing it is shorter than you expect.
About this guide: How this guide came about, how it is maintained, and how to send corrections.

Last updated 5 October 2026.