What your building's owner might worry about
At some point in your life, you will either find yourself having to deal with a landlord, or having to deal with being a landlord (even if you are the only one you're lording over in your home.) So it's important to think from the landlord's perspective when planning and caring for your container garden.
Put on your landlord hat and think about how gardening might affect where you live.
Building issues: How will it make the building look? Will it cause any damage to the building?
Safety issues: Could someone trip and fall? Could containers fall and injure someone?
Neighborhood issues: Will the neighbors complain about how it looks? Will it attract unwanted attention from unwanted neighbors?
If you are a renter, the best strategy is to make your landlord your ally. You will probably find that your landlord is much more encouraging and helpful if you are sensitive to his/her concerns. If you don't have strong feelings about colors or which plants to grow - ask your landlord if s/he has any favorites. If you do a good job, before too long, the landlord may alert you to other gardening opportunities in places previously off limits or otherwise beyond consideration.