Houses, apartments, factories, offices, schools, roads, and bridges are only some of the products of the construction industry. This industry’s activities include work on new structures as well as additions, alterations, and repairs to existing ones. (Some government establishments do the same work and employ a significant number of people, but information about them is not included in this article.)

The construction industry is divided into three major segments. Construction of buildings contractors, or general contractors, build residential, industrial, commercial, and other buildings. Heavy and civil engineering construction contractors build sewers, roads, highways, bridges, tunnels, and other projects. Specialty trade contractors are engaged in specialized activities such as carpentry, painting, plumbing, and electrical work.

Construction usually is done or coordinated by general contractors, who specialize in one type of construction such as residential or commercial building. They take full responsibility for the complete job, except for specified portions of the work that may be omitted from the general contract. Although general contractors may do a portion of the work with their own crews, they often subcontract most of the work to heavy construction or specialty trade contractors.

Specialty trade contractors usually do the work of only one trade, such as painting, carpentry, or electrical work, or of two or more closely related trades, such as plumbing and heating. Beyond fitting their work to that of the other trades, specialty trade contractors have no responsibility for the structure as a whole. They obtain orders for their work from general contractors, architects, or property owners. Repairwork is almost always done on direct order from owners, occupants, architects, or rental agents.