Comprehensive and Detailed Explanation From Exact Extract:
Exterior shading devices control daylight penetration and solar heat gain:
Roof overhangs (A) shade upper window areas and reduce direct sunlight in summer.
Horizontal louvers (C) block high-angle summer sun but allow low-angle winter sun.
Vertical louvers (E) control low-angle sun from east/west directions and reduce glare.
Horizontal girts (B) and spandrel panels (D) are structural or opaque elements, not designed for
daylight control.
Parapet walls (F) can shade roof edges but are not primary daylight controls.
Reference:
ARE 5.0 PPD – Environmental Conditions and Context, Daylighting and Solar Control
The Architect’s Handbook of Professional Practice, 15th Edition – Sustainable Design
