Ideas for "Spaces"

I'm posting here to collect input from the community. Any suggestions or comments welcome.

We're working on an idea for collaboration within zzTakeoff where you could potentially isolate takeoff & annotation data (and eventually real-time chat) within a project into multiple "spaces". The primary purpose of these spaces would be for collaboration. So each project would have a default "Main" space. You could add additional spaces to collaborate between you and other groups of users. Each space would have an isolated view. So, in the example below, a General Contractor could setup a project, and create a space within that project for drywall, electrical, home owner, etc. Then any users invited to that space could collaborate without seeing the takeoff & annotation data from the other spaces. I could see people even creating another "space" within a project just to have a clean slate to do "what if" scenarios using the same set of plans, without having to create a whole new project.