https://www.velux.co.uk/professional/products/cad-bim/3d-objects
- Roof Windows Library
a path through the web to GDL sources
https://www.velux.co.uk/professional/products/cad-bim/3d-objects
http://www.puertasgismero.es/en/bim-english
http://materia.se/en/downloads/
https://architekt.dormakaba.de/
https://www.m-sora.si/en/help/bim-archicad