Estimation & Measurement – Identify the incorrect rule In civil engineering quantity measurement (as per standard practice like IS 1200), which of the following statements about deductions is NOT correct?

Introduction / Context:
Estimating and costing in civil engineering follow codified measurement rules (e.g., IS 1200 series). These rules specify when deductions are or are not made for small openings, embedded items, pipes, and the ends of members. The question tests recognition of the standard thresholds and the contexts (concrete, masonry, plaster).

Given Data / Assumptions:

• General building works under standard measurement rules.
• Typical items: RCC concrete, brick masonry, plastering, small service penetrations, ends of beams/posts.
• Threshold areas are used to simplify measurement for small interruptions.

Concept / Approach:
Each statement corresponds to a common rule. We check whether the threshold magnitude and the work context match standard practice. In particular, plastering has a larger no-deduction threshold for ends of members than 500 cm^2.

Step-by-Step Solution:
1) Reinforcement in RCC: Concrete volume is measured without deducting steel; statement (a) is correct.2) Openings in masonry: Very small openings (about 0.1 m^2) are commonly ignored; statement (b) is correct.3) Small pipes/conduits: Very small pipe penetrations (on the order of 100 cm^2 cross-section) are often ignored in practice; statement (c) is acceptable.4) Plastering ends of dissimilar members: The customary no-deduction limit is around 0.5 m^2 (5000 cm^2), not 500 cm^2; (d) understates the threshold and is therefore incorrect.

Verification / Alternative check:
Cross-reference common clauses: concrete measurements exclude steel; masonry ignores tiny openings; plastering uses a relatively generous threshold for ends of beams/posts (about 0.5 m^2). The mismatch in (d) confirms it as the incorrect statement.

Why Other Options Are Wrong:

• (a) Standard RCC practice; no deduction made for steel volume.
• (b) Tiny openings in masonry are ignored to simplify measurement.
• (c) Very small pipe voids are ignored; threshold scale is reasonable.
• (e) “None of these” is wrong because (d) is indeed incorrect.

Common Pitfalls:
Mixing the rules for plaster, masonry, and concrete, or confusing units of m^2 versus cm^2 can lead to wrong judgments about thresholds.

Final Answer:
No deductions are made for the ends of dissimilar members up to 500 cm^2 cross-sectional area in plastering