新築 (shinchiku) means “new construction”

More examples

駅の近くに新築のマンションが完成しました。eki no chika ku ni shin chiku no ma n sho n ga kan sei shi ma shi ta

A newly built apartment building has been completed near the station.

Describes the result or process of creating a building that did not previously exist.

中古chūko: A building or home that has been previously owned or used.

これまでなかった建物を新しく建てること、またはその建物。ko re ma de na ka tta tate mono o atara shi ku ta te ru ko to ma ta wa so no tate mono

新 (shin, "new") and 築 (chiku, "build") form the compound 新築 (shinchiku), whose parts point to building something new.

Japanese housing advertisements use 新築 (shinchiku) for homes that are newly constructed, while a previously occupied home is not normally labeled this way.