They have just had a new update, as to where you can walk and edit on blackspaces, if you dont know how this is how:
1: Click on the name of your apartment (Apartment Info)
2: Look for The Blackspaces section
3: Select the ones you would like in your home.
REMINDER : Your selection will be for the home your on ONLY
ALSO : THE OWNER OF ANOTHER HOUSE MUST ENABLE THE WALKING FOR YOU TO BE ABLE TO WALK ON THE BLACK SPACES


Hope I was helpful in any way.