i'm looking for complete informations of a building, height, length, areas and all that. where can I get those?

You might be able to contact Harvard's physical plant and/or internal architect departments for these details.

It is also possible that a search of old Cambridge MA or Harvard newspapers might give the external dimensions of the building.

If you want complete and exact information, you'll need to see the plans for the building. I'm sure the GSD either has those or can direct you to the Harvard office that does.

Omg