In a plinth area estimate for buildings, which of the following items is NOT included within the plinth area measurement?

Introduction / Context:
Plinth area is the built-up covered area measured at floor level to the outside of walls. It forms the basis for preliminary cost estimates and benchmarking. Understanding inclusions and exclusions ensures consistent comparisons and budgeting.

Given Data / Assumptions:

• The estimate concerns roofed, covered spaces within the building's plinth outline.
• Wall thickness and internal rooms are part of the plinth area.
• Open-to-sky spaces are generally excluded.

Concept / Approach:
Plinth area includes thickness of walls, rooms, verandahs (if roofed and within the plinth line), toilets, stair/lift shafts (as applicable), etc. Open courtyards (uncovered) are excluded, even if bounded by walls, because they are not roofed covered areas at the floor level.

Step-by-Step Solution:
Identify covered vs. uncovered spaces at floor level.Include: wall thickness, rooms, verandah, W.C. as they are covered within the plinth outline.Exclude: open-to-sky courtyard area.Therefore, Courtyard area is not included in plinth area.

Verification / Alternative check:
Guides on plinth-area estimation explicitly exclude open courts and light-wells; they may be considered in site coverage, not plinth area.

Why Other Options Are Wrong:

• A–D are all part of the covered built-up area and hence included in plinth area.

Common Pitfalls:
Including open-to-sky courts; confusion between carpet area, built-up area, and plinth area definitions.

Final Answer:
Courtyard area (open-to-sky internal court)