大楼(dà lóu) - (large multi-storey) building, block, tower in Mandarin

大楼 (dà lóu) is the tall block: an office tower, a hospital wing, a government headquarters, a big apartment building. The word carries the idea of many floors, which is what 楼 supplies, and of scale, which is what 大 supplies.

It takes 座 or 栋 as its measure word, and it is the natural noun for saying where you work or which entrance to meet at: 我在教学大楼门口等你.

English speakers overuse it because "building" is such a broad word at home. In Mandarin it is narrower. A house is 房子. A shop or a low structure is just 房子 or the name of the place. A building in the architectural sense, the thing an architect designs, is 建筑. Keep 大楼 for something you would need a lift to get to the top of.