Commercial Building construction involves building projects that can be leased or sold in the private sector. These spaces can be anything from offices and manufacturing plants to medical centers and retail shopping centers. Each commercial construction project varies in size and effort and is unique in its own way. The designs and layouts of a structure are decided entirely by the client. Each client is unique so projects will be different. In commercial construction, a project can be separated into 3 sizes: small-scale, medium-scale, and large-scale.