The unitized system is assembled on the building as panels. The mullions and rails are fabricated as half sections instead of tubular sections, which mates at assembly time to form the curtain wall system. The panels are installed in shingle fashion, starting from the bottom of the building and going around each floor and up the building.

Unitized curtain wall has the advantages of speed; lower field installation costs; and quality control within an interior climate controlled environment. The economic benefits are typically realized on large projects or in areas of high field labour rates. Unitized curtain wall is a curtain wall that is engineered, manufactured, assembled, and glazed at a factory, and shipped to the project site for field installation. Each panel varies in size, but are typically around 1200 mm wide and 3300 mm to 4000 mm in height.