building site vs lot

building site and lot both are nouns.

Word	Noun	Adjective	Verb	Adverb
building site	Yes	No	No	No
lot	Yes	No	Yes	No

As nouns, lot is a hypernym of building site; that is, lot is a word with a broader meaning than building site:

building site (noun)	lot (noun)
a lot on which there are no permanent buildings	anything (straws or pebbles etc.) taken or chosen at random
	an unofficial association of people or groups
	any collection in its entirety
	a parcel of land having fixed boundaries
	(often followed by `of') a large number or amount or extent
	your overall circumstances or condition in life (including everything that happens to you)

building site (verb)	lot (verb)
	administer or bestow, as in small portions
	divide into lots, as of land, for example