The best method to place zones is the Inner Edge method
This means the zone ‘connects’ with all its bounding elements
So if you update or move the walls, a simple Update Zones command will update all the zones according to the new boundaries
One issue you may encounter is open plan spaces where one space may have several different uses
For this use the Line Tool to define the boundaries between these spaces so the Inner Edge Method can still be used.
Just open the Line Settings and tick Zone Boundary