Idk about this particular confusion, lolol, but now I finally understood what you originally meant. *facepalm* :D I thought you meant an apartment door that could be open without a key by some other means, like a card or a code or something. I don't know those. But if you mean in general then yeah, I only know doors that can be opened from the ouside without a key, simply because no one locked them. Like, they open from the inside and the outside the exact same way, indefinitely, as long as no one locks them with a key. And then once someone locks them, you'll need a key, from the inside and from the outside. (Thought not always from the inside - sometimes the inside only has one of those bolts that you flip.) Ooooof, this is all very complicated. xD