Thanks everyone. I’ve made progress on the room volumes. You can use it to ensure a room is created at a particular location in the floor, and can span multiple floors.
is the building lobby, that spans 3 floors, and the building height is 4 floors. The top floor is not affected by the volume
http://i.imgur.com/uwKPkbbm.jpg http://i.imgur.com/tfurbQ7m.jpg
If you extend the volume all the way up, it would create an open space in the building. I’ve created a garden in the middle of the building with a volume
http://i.imgur.com/i89eW8Yh.jpg
http://i.imgur.com/6BauHaZh.jpg
http://i.imgur.com/vjrDITkh.jpg
http://i.imgur.com/aqqVaf5h.jpg
http://i.imgur.com/hpOZYHth.jpg
http://i.imgur.com/0oLP2wjh.jpg
http://i.imgur.com/A2q6d58h.jpg
You can specify the Marker names in the volume configuration to customise the generated content within the volume. In the volume config where the garden is created, I specified the following marker names

Then I added those markers in the theme file to create the tree, grass, glass walls etc
