Well, that would be ideal solution. But we are far from that in the AEC industry. There is FreeCAD Arch and also Blender BIM, but none of those are even close to being able to use them in production. But hopefully with time and with current growing OpenBIM initiative it will get better. It is very impressive what Ton Roosendaal was able to create with Blender - a free open source software which is fully competitive to the most expensive industry leaders.
