Units of Measurement – When is square metre (m^2) used? Choose the item that is typically measured in square metres for BOQ purposes (with thickness specified), rather than in cubic metres, numbers, or tonnes.

Introduction / Context:
Selecting the correct unit of measurement improves comparability of rates and clarity in BOQs. Masonry and blockwork are often priced by area when the thickness is standard, while mass or volume-based items (concrete) are measured by cubic metres. Discrete items like posts are counted by number.

Given Data / Assumptions:

• Standard IS-style measurement conventions.
• Walls built with hollow concrete blocks of a given thickness (for example, 100 mm, 150 mm).
• Concrete in structural members is volumetric work.

Concept / Approach:

Block masonry walls are planar elements; the BOQ usually states thickness and measures the area in m^2. Concrete in foundations or RCC frames is measured by volume (m^3) because the thickness and geometry vary. Precast elements like fencing posts are counted by number with size and grade stated.

Step-by-Step Solution:

Verification / Alternative check:

Check typical BOQs and SORs: block masonry lines show m^2, concrete lines show m^3, and posts appear under numbers.

Why Other Options Are Wrong:

PCC and RCC are measured in m^3; posts are per number; “None of these” is invalid since block walling fits the m^2 unit.

Common Pitfalls:

Confusing blockwork with concrete; omitting thickness specification for m^2 items.

Final Answer:

Hollow concrete block walling (specified thickness)