Curtain walling detail provides a lightweight framework into which a range of infills can be inserted. This includes glass, panels and window units as well as ventilation, acoustic and fire elements. It is commonly used in commercial projects but is also gaining ground on residential projects too.

A key visual feature of a curtain wall is the width and depth of the mullion frames (see Glazing). These can be tailored to meet project requirements by varying frame widths and heights and by using steel stiffeners within the frames to narrow sightlines where required. Lateral load resistance requirements (wind loads, spans) often dictate frame depth too.

Mastering the Details: A Comprehensive Guide to Curtain Walling Design and Construction

Insulation and air/vapor barriers must be detailed to minimize condensation in opaque curtain wall areas that are subject to wide swings of temperature and humidity. In addition, condensation drainage provisions (weep holes or gutters) must be coordinated with the fenestration system to avoid blocking these paths of moisture flow.

Generally, the curtain wall is designed to support building lateral forces, resist wind and seismic-induced sway and to support the own dead load weight of the mullions and anchors.

Most curtain walls are unitized systems, meaning that the frame and glazing are fabricated in factory conditions and assembled at the building site. This allows for rapid installation and limits field quality control costs, particularly in locations where labour rates are high.