Building Tools: a Blender add-on for parametric buildings

Where the add-on came from

The background section explains the origin, and it says more about the design than a feature list would. The addon started out as a collection of scripts used to create 3D models for games. After a couple of months of development, the author noticed that most of the scripts were geared towards creating buildings and environments, and decided to make a proper add-on out of them, and Building Tools was born. That origin explains the feature set. A general modelling add-on would offer primitives and modifiers, while this one is narrow by construction, aimed at the case where an artist has drawn a floorplan and needs a three-dimensional building from it, with the openings placed where the plan says. The primary language is Python, the licence is MIT, the homepage is the documentation site, and the last push was on 2026-09-24 with releases v1.0.13 on 2025-05-16, v1.0.12 on 2024-01-03 and v1.0.11 on 2023-12-17. The project was inspired by the Ghost Town add-on for 3DS MAX.

The element list, which is the feature list

The features are eight things, and each links to a wiki page describing it. There is Floorplans, which is the input the rest of the pipeline consumes. There are Floors, so a building can be stacked vertically from a plan. There are Doors and Windows, and the interesting entry is Multigroup, described as door-window combinations, which is the feature that saves the most time, since a facade with a regular rhythm of openings is exactly the case that hurts when modelled by hand. Then there is Roof, Stairs and Balcony. The set is complete enough to block out a street of buildings, which is the intended use. It is not a building design tool, there is nothing about structure, materials or lighting, and the add-on leaves the art direction entirely to the artist.

Installing it, and the zip file requirement

The install is three steps, and the first one is a release download rather than a package manager. Download the add-on as a zipped file from the releases page, then in Blender go to Edit, then Preferences, then Add-ons, then Install, and select the downloaded file. The reason the add-on is distributed as a zip is that is what Blender's own installer expects for an add-on, since Blender treats an add-on as a directory with a manifest and reads it as an archive. There is no pip or conda package, because the add-on runs inside Blender's own Python rather than in a system interpreter. The release asset name carries the version, building_tools_v1.0.13.zip, so a given download corresponds to a given version.

The developer workflow, which runs inside Blender

The project uses PDM rather than pip, and the scripts in the project file show the whole loop. `test` runs `blender --window-geometry 0 0 1 1 --no-window-focus -P tests/__main__.py`, which is the detail that tells you the test suite executes inside a real Blender instance with a minimal window, rather than against a mocked bpy. `build` runs `python scripts/make-release.py` to produce the release archive, and `build-dev` does the same with the `latest` argument. `install-dev` runs `blender -P scripts/install-dev-addon.py`, and `dev` is a composite of those two, so a change is built and reinstalled in one command. `format` runs black on the `btools` package and `check` runs mypy over it. The lint dependencies include `fake-bpy-module-latest`, which is a stub package for Blender's bpy module so that mypy and other static tools can check the code without a Blender installation.

The repository layout, and the docs site

The tree is organised around the add-on package and its supporting material. There is `btools/` for the add-on source, an `__init__.py` at the root, `assets/` for the bundled resources, `tests/` for the test suite, `scripts/` for the release and install helpers, and `docs/` for the documentation site. The Makefile shows the documentation side is separate, with a `web-serve` target that runs `bundle exec jekyll server --watch` inside the docs directory, meaning the site is a Jekyll site built with Ruby and Bundler, and a `web-install-deps-linux` target that installs ruby, ruby-dev, rubygems and then the bundler and github-pages gems. So there are two toolchains in one repository, Python with PDM for the add-on and Ruby with Jekyll for the site, and the Makefile handles the second one. The `RELEASE.md` file and the `pdm.lock` lockfile sit at the root, and the project requires Python 3.10 or newer.

Contributing, and the compatibility statement

The contributing section is brief. You can fork and submit pull requests, and for bugs you create an issue that describes the problem and attaches relevant info or logs, while for feature requests you create an issue and add the Enhancement label. There is a Discord server for chatting with other contributors. The status section carries the compatibility statement, and it is the one line to check before you commit to the add-on: the version is v1.0.13 and it is Blender 4.0 compatible. For an add-on that reaches into Blender's own API, that means a Blender upgrade can break it, and the project has not published a release since May 2025 even though the code was pushed in September 2026, so the current state of the master branch is ahead of the last tagged build. The authors are listed as ranjian0, luckykadam and MCrafterzz, with a contact invitation, and there is a PayPal link for support.

Editorial conclusion

Adopt Building Tools if you are blocking out buildings for a game environment in Blender and want the repetitive elements generated rather than modelled, since doors, windows, stairs and balconies are the parts that multiply across a street. Skip it if your architecture is bespoke and non-repeating, because the parametric approach pays off in volume rather than in uniqueness. Before you install, note that the add-on has to be built from the repository with `python scripts/make-release.py` or you can download the zipped release directly, and that the tests run inside Blender itself through `blender -P tests/__main__.py`, so a headless Blender install is needed to run them.

Frequently asked questions

Official sources

1. License: MIT
2. Project website
3. ranjian0/building_tools on GitHub
4. README
5. Releases