-story building; -storey building
Suffix attached to a number to indicate the number of floors of a building, e.g. 3階建て (three-story building).
That building is a ten-story building.
I live in a two-story house.
Variant without okurigana; seen in some contexts but 階建て is preferred.
Compound of 階 (kai, 'floor, story') + 建て (date, 'building, construction').