The NCIDQ IDPX exam tests the designer’s understanding of when structural engineering expertise is required for interior installations. A structural engineer is needed when an installation impacts the building’s structural integrity, such as adding significant loads or requiring attachment to structural elements.

Option A (A wall-mounted furniture workstation):A wall-mounted workstation typically attaches to a wall with brackets. While it adds some load, it is generally minimal and can often be supported by standard wall framing (e.g., studs). A structural engineer is not typically required unless the wall itself is structurally inadequate, which is not indicated.

Option B (A demountable partition wall):Demountable partition walls are lightweight, non-load-bearing systems designed for flexibility. They do not typically impact the building’s structure, so a structural engineer is not required.

Option C (A non-load-bearing interior wall):A non-load-bearing wall, by definition, does not support structural loads and is designed to be self-supporting or attached to the floor and ceiling. It does not require structural engineering input.

Option D (An operable partition wall):Operable partition walls are large, heavy, movable walls often used in spaces like conference rooms or ballrooms. They are typically suspended from a track attached to the building’s structural system (e.g., ceiling joists or beams). The significant weight and dynamic load of the partition, along with the need to ensure the structural system can support it, require a structural engineer’s involvement to verify load capacities and attachment details.

Verified Answer from Official Source:

The correct answer is verified from NCIDQ’s official study materials on coordination with other disciplines.

“Installations such as operable partition walls, which impose significant loads on the building structure, require coordination with a structural engineer to ensure the building can support the additional weight.” (NCIDQ IDPX Study Guide, Coordination Section)

The NCIDQ IDPX Study Guide highlights that operable partition walls, due to their weight and attachment to the structural system, necessitate a structural engineer’s involvement to ensure safety and compliance with building codes. Option D is the correct choice, as it is the only installation likely to require structural engineering input.

Objectives:

Understand when to involve a structural engineer in interior projects (NCIDQ IDPX Objective: Coordination).

Apply knowledge of building systems to ensure safe installations (NCIDQ IDPX Objective: Building Systems).