IS 1200 fixes masonry and plastering measurement: brickwork by net volume (thickness × net area), plastering by net finished area, with the most argued rule — opening deductions: openings below a stated small-size threshold are NOT deducted (jambs/soffits offset the labour), while larger openings ARE deducted per the size rules. Consistent application of the deduction thresholds is what makes the bill defensible.
Key Requirements
•Brickwork measured by net volume (specified thickness × net wall area)
•Plastering/pointing measured by net finished area on the specified face(s)
•Openings below the stated small-size threshold: NOT deducted; larger openings deducted per the rule
•No deduction for embedded fixtures/pipes below the specified size
•Apply the IS 1200 thresholds consistently across the project
Practical Notes
✓The opening-deduction threshold is the single most-argued masonry/plaster rule — fix it from IS 1200 in the BOQ preamble and apply it uniformly.
✓Small openings are not deducted because the extra jamb/soffit work offsets the lost area — it is a deliberate, standardised simplification, not an error.
Common Mistakes
⚠Inconsistent opening-deduction thresholds across the project.
⚠Deducting every small opening (against the IS 1200 rule) or deducting none.
⚠Measuring gross wall area without net-of-openings rules for large openings.