Not expanded to ops for rent I can’t delete floor or rooms

I’m playing with for rent and I’m trying to add another property on the lot. I create a room or I just place the floor but then I can’t delete it- it says ‘not expanded to ops’ or nothing to delete (I can delete walls just not the floor) 

I tried doing it using the landlord, it didn’t work so I tried with a sim which lives in another property on the lot and still it says the same thing.

Help please