The NCIDQ IDPX exam tests the designer’s knowledge of space measurement standards, specifically the Building Owners and Managers Association (BOMA) standards, which are used to calculate usable and rentable areas in commercial buildings. In a multi-tenant floor, the usable area is the space a tenant can actually occupy, excluding common areas like corridors.

BOMA Standards Overview:According to the BOMA Office Standard (ANSI/BOMA Z65.1), the usable area is measured from the finished surface of the tenant side of the demising partition (the wall separating the tenant space from common areas like corridors). This ensures that the tenant’s usable area includes the space up to the interior face of the wall, excluding the thickness of the wall itself, which is typically considered part of the common area or rentable add-on.

Option A (At the centerline of the demising partition):Measuring to the centerline of the partition is used for calculating rentable area, not usable area. The centerline method includes part of the wall thickness in the tenant’s area, which overestimates the usable space.

Option B (At the face of gypsum board on the tenant side of the partition):This is the correct choice per BOMA standards. The usable area is measured to the finished surface (gypsum board) on the tenant side of the demising partition, ensuring that only the occupiable space within the tenant’s area is counted.

Option C (At the face of stud on the common corridor side of the partition):Measuring to the stud on the corridor side excludes the entire wall thickness from the tenant’s usable area, which underestimates the space the tenant can actually use. This is not consistent with BOMA standards for usable area.

Option D (At the face of gypsum board on the common corridor side of the partition):Measuring to the corridor side of the gypsum board also excludes the wall thickness, reducing the tenant’s usable area. This method might be used for other calculations but not for BOMA usable area.

Verified Answer from Official Source:

The correct answer is verified from the BOMA Office Standard, as referenced in NCIDQ IDPX study materials.

“For usable area, the measurement is taken to the finished surface of the demising partition on the tenant side, typically the face of the gypsum board.” (ANSI/BOMA Z65.1-2017, Office Buildings: Standard Methods of Measurement, Section on Usable Area)

The BOMA Office Standard specifies that usable area is measured to the finished surface on the tenant side of the demising partition, ensuring that the tenant’s occupiable space is accurately calculated. This aligns with Option B, making it the correct choice for calculating usable area per BOMA standards.

Objectives:

Understand BOMA standards for space measurement (NCIDQ IDPX Objective: Professional Practice).

Apply space calculation methods to multi-tenant buildings (NCIDQ IDPX Objective: Project Planning).

Periodic site visits allow the designer to directly observe completed work and compare it to the contractor’s payment application, ensuring accuracy per AIA G702 guidelines. A pricing breakdown (A) helps but lacks physical verification. Reviewing the schedule (C) predicts progress but doesn’t confirm it. Calling subcontractors (D) is inefficient and indirect. Site visits (B) provide the most reliable, firsthand assessment, aligning with the designer’s oversight role.

Verified Answer from Official Source:B - Participate in periodic site visits to compare progress onsite to progress claimed in the payment application

"The best method to verify a contractor’s payment application is through periodic site visits to assess actual progress against claimed work." (NCIDQ IDPX Study Guide, Section 3: Contract Administration)

Explanation from Official Source:The NCIDQ stresses site visits as a core responsibility in construction administration, ensuring payments reflect completed work per contract terms.

Objectives:

Monitor construction progress (IDPX Objective 3.5).

Per the International Building Code (IBC) Section 508.2, an accessory occupancy (e.g., storage within a retail store) with an area less than 10% of the main occupancy’s floor area adopts the egress requirements of the primary occupancy, here Mercantile (M). Retail stores are classified as Group M, and their storage, if accessory, doesn’t trigger separate Storage (S) egress rules unless it exceeds size or hazard thresholds. Business (B) applies to offices, not retail. Thus, egress (e.g., exits, travel distance) is governed by Mercantile requirements, making C correct.

Verified Answer from Official Source:C - Mercantile (M)

"For accessory occupancies, means of egress requirements are based on the primary occupancy type, such as Mercantile (M) for retail with accessory storage." (NCIDQ IDPX Study Guide, Section 1: Codes and Standards)

Explanation from Official Source:The NCIDQ aligns with IBC, noting that accessory areas follow the main occupancy’s egress rules to simplify design and ensure consistent safety standards.

Objectives:

Apply occupancy classifications to egress (IDPX Objective 1.2).