CalifJim, I like your information hiding explanation. To make sure I get it right, is the following example correct?
This morning some guy walked to my car and kicked the door, leaving a big dent.
I hope it wouldn't confuse my listener into thinking my car has only one door.
YoongLiat,
I mean the building next to this building when I say the building next door. Another example is
This window looks directly into an apartment in the building next door.
What do you think is the right phrase?