Section Drawing

What is Section Drawing?

A section drawing, also called a cross-section or building section, is created by conceptually slicing through a structure vertically to expose its interior composition. This essential architectural document reveals information that cannot be seen in plans or elevations, including ceiling heights, floor-to-floor dimensions, structural systems, and the vertical relationships between spaces.

Architects strategically choose section cut locations to communicate the most important spatial qualities of a design. A section through a dramatic double-height living room, for instance, conveys the sense of volume and light that makes the space special. Sections through stairs show rise and run dimensions, headroom clearances, and handrail heights.

Building sections are critical for understanding how a structure meets the ground and reaches toward the sky. They show foundation depths, basement configurations, roof slopes, and parapet conditions. The relationship between interior floor levels and exterior grade is clearly depicted, which is essential for accessibility compliance and drainage design.

Technical sections include detailed information about wall assemblies, insulation placement, waterproofing membranes, and structural connections. These drawings coordinate the work of multiple trades and ensure that the building envelope performs as intended for thermal comfort, moisture management, and structural integrity.