As the title says, I have created a model of my home, made a group of the walls, and placed that group in its own layer. But that’s ALL the walls, interior and exterior. Do all the walls belong together like this, or do you recommend something like sub-groups for the walls of different rooms?
Well, the choice should depend on if you see any benefit to it. I’d personally only go for that extra work if for example I was planning on remodeling and tearing down some of those walls.
Doing this would involve exploding the current group breaking down each wall segment into a potential group, pulling it down, marking and grouping it and then pulling it up again like so:
After you’re done you could then mark all the groups you created and then add them to another group.
A lot of people advocate a group for exterior walls and another for interior walls. That works well.
It is much more difficult to create groups after the event as you have to make sure you are selecting very carefully when you create the group. And the more ungrouped your drawing is, the worse it gets (but never impossible). Best is to make groups as you go along. Using a shortcut makes light work of it.
Remember too that anything that is repeated (including things that are mirror images) are best made as components, so that when you change one, the other changes too and so saves much work.