All construction materials used in a contract for the construction, alteration, or repair of any public building or public work in the United States, must be from the United States unless an exception applies. Discrete systems, as defined in FAR Subpart 25.003, that are incorporated into a public building or work and that are produced as complete systems, are evaluated as a single and distinct construction material.
See FAR Subpart 25.202 for the allowable exceptions to acquire foreign construction materials in compliance with the Buy American Act. The 50% significant domestic component test does apply similar to construction materials like under FAR Subpart 25.1 -- Buy American Act – Supplies. See FAR 52.225-9 -- Buy American Act–Construction Materials, definition of Domestic construction material.