That depends on the building, and on which dimension of it you're measuring.
If you're measuring the height of the building, then 'meters' probably does it for every
case. The tallest building I know off the top of my head is the Amoco/Aon building in
Chicago ... the 3rd tallest in the city ... which is 346 meters above the street level,
so a building would have to be almost 3 times as tall as that one before 'kilometers'
might become a better choice.
If you're measuring the length or width of the building, 'meters' is usually the better
choice. But if you're doing one like the Pentagon, or the US Military Records Center
in St. Louis, then 'kilometers' might produce the more convenient number.
Usually, you would use kilometers.
Grams is no good - it is a measure of weight not length. Kilometers measure length - but only if your table-top is a few miles long. Most appropriate would be Meters - your average dining table is about one-and-a-half meters long.
it depends. If you were mesuring length then you would use meters. If you were measuring volume you would use cubic meters. If you were measuring weight you would use metric tons.
Miles or Kilometers
you would measure a wall in meters
You could if you wanted to, but you must do so in fractions of a kilometers, it is more sensible to do so with feet or meters.
Yes or in yards