Principle of units; data for detailed estimate

Principles of units of measurement

Every item of work is measured and paid in one unit, chosen by the nature of the work, as per IS 1200 and the Nepal standard practice:

1. Work in one dimension (length governs, section fixed) is measured in running metre (m): e.g. cornice, skirting, pipes, railing.
2. Work in two dimensions (thickness fixed) is measured in square metre (m²): plastering, flooring, painting, formwork, half-brick wall.
3. Work in three dimensions is measured in cubic metre (m³): excavation, concrete, brickwork, masonry.
4. Small, countable items are measured in numbers (nos.): doors, fixtures, W.C.
5. Items sold by weight are measured in kg, quintal or tonne: reinforcement, structural steel.
6. Items that cannot be measured are paid as lump sum (L.S.).
7. Measurement is of the net finished quantity in place; deductions are made for openings and voids as per the rules. Dimensions are measured to the nearest 0.01 m, areas are worked out to the nearest 0.01 m² and volumes to the nearest 0.01 m³. The unit of measurement is the same as the unit of payment.
8. The description includes all work, materials and incidental labour necessary to complete that unit.

Data required for a detailed estimate

1. Complete drawings (plans, sections, elevations, details).
2. Specifications of materials and workmanship.
3. Rates: District Rate and DUDBC norms for rate analysis.
4. Site data: soil, lead, water, labour availability.
5. Item-wise quantity calculation, then abstract of cost.
6. Contingency, taxes and overhead provisions.