building (n.)

c. 1300, "a structure;" late 14c., "act or process of constructing;" verbal noun from build (v.). Building-block is 1846 as "one of a set of children's play blocks;" 1849 as "temporary support on which a ship's keel rests while the ship is being constructed;" 1856 as "cinder-block, concrete block, artificial stone block used in building construction." Figurative sense "basic unit from which something is constructed" is by 1955.