You can create a plan to give an architect a very good idea about what you want but it requires professional software to create the plans that a contracter can use.

This, I think, is the point. I'm beginning a remodel project. A building site plan is the first submittal to the permit authorities. It shows land features in plan view, such as watercourses, wetland boundaries, property lines and so forth. It isn't a framing or structural plan.

I think I might be able to create a site plan using this software, using "walls" to create lines and circles. Unfortunately my drawing options are somewhat limited in Linux. But I agree, this is very useful software, just not intended for creating detailed contractor drawings.