Building estimate subheads: Which of the following groups correctly lists common subheads used in a building estimate?

Introduction:
Comprehensive building estimates are broken into subheads to organize quantities and costs by trade and work sequence. Recognizing standard subheads ensures accurate BOQs (Bills of Quantities) and simplifies rate analysis and tendering.

Given Data / Assumptions:

• Common building works include earthwork, concrete, masonry, roofing, finishes, and services.
• Each option lists legitimate subhead groupings encountered in detailed estimates.
• The question asks which set(s) can be valid subheads.

Concept / Approach:
Standard practice groups similar items: excavation/earthwork; concrete (plain or reinforced); brick/stone masonry; wood and steel works; roofing; finishing (plastering, painting, flooring); and services (water supply, sanitary installations, electrification). Multiple correct groupings can exist as long as they reflect conventional subhead structure.

Step-by-Step Solution:
Check option a: Earthwork, Concrete work, Brick work → valid core subheads.Check option b: Brickwork, Stone work, Roofing → valid trade-based set.Check option c: Brickwork Flooring, Wood work, Steel work → flooring, wood, and steel are legitimate subheads.Check option d: Plastering/pointing, finishing, water supply and sanitary → finishing and services subheads are standard.Since all are legitimate, choose the combined option.

Verification / Alternative check:
Model BOQs from public works departments and standard texts show similar subhead divisions, sometimes with more granularity but consistent in principle.

Why Other Options Are Wrong:
a–d each list valid subheads but only partially cover the full scope; the best answer acknowledging all is option e.

Common Pitfalls:
Confusing subheads with individual items; subheads are umbrella categories that may contain numerous line items.

Final Answer:
All of the above.