Curtain Wall Systems: A Primer provides a comprehensive introduction to the use of curtain wall systems in building envelopes. Today’s curtain wall systems go beyond the basic functions of providing natural lighting and protecting the building interior from the external environment. These systems now are expected to conserve energy and ensure occupant comfort by controlling heat flow and solar radiation. Moreover, curtain wall systems must be designed for acceptable performance under natural disasters and human-made hazards. The design, fabrication, construction, and maintenance of advanced and efficient curtain wall systems demand the involvement of professionals from several fields of engineering and building technology. This Manual of Practice compiles a basic review of the many aspects of curtain wall systems that affect their design and performance. It highlights the materials used to manufacture curtain walls for low-rise to high-rise construction and describes different types of tests, mockups, and inspections. Methods of improving the energy performance, waterproofing, and wind loading of curtain walls are assessed. Specialised aspects of curtain wall design and analysis for extreme events, such as earthquake and bomb blast, are explored. Innovative façade design and new curtain wall and glazing systems are covered as well. MOP 126 is written for architects, structural engineers, HVAC engineers, general contractors, building owners, and building operators who are new to curtain wall systems and want to learn more about this specialised and emerging field. Prepared by the Committee on Curtain Wall Systems of the Architectural Engineering Institute of ASCE.