Thanks ThomThom for this awesome tool.
I managed to make it work in Sketchup 2018.
- Download Citelum's GitHub archive (thanks for uploading it!)
- Unzip it in your Plugins folder (for me C:\Users\YOURNAME\AppData\Roaming\SketchUp\SketchUp 2018\SketchUp\Plugins)
- Edit Plugins\citygen\modules\bldg_gen.rb, add a # before : require 'offset'
Cheers!