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Whole-House Estimator — the fifteen-minute takeoff

Every classic thumb rule applied to your house at once, with the rule shown on each line

All floors added together

135 litres/person/day, design figure

The common Indian house — mid range

The building type picks where in each published range your estimate sits — the page’s own rule is low end for a simple single storey, high end for G+2. The range beside every line shows the full spread, so you can see how much the choice moves.

Steel — the number every quote turns on

4.80 tonnes

1,200 sq ft · G+1 · at 4 kg/sq ft

Steel (TMT)4.80 t

3.5–4.5 kg/sq ft · full range 4.20–5.40 t · Floors add columns’ share, seismic detailing adds confinement steel — single storey sits at 3.5, G+2 in Zone IV at 4.5 · price it

Cement480 bags

0.4 bags/sq ft · full range 480–480 bags · Rises with plaster-heavy designs, falls slightly with AAC-block walls · price it

Sand16.2 brass

1.2–1.5 cft/sq ft · full range 14.4–18.0 brass · ≈ 4.5 t per brass — you pay for its water weight, so buy dry · price it

Aggregate14.4 brass

1.1–1.35 cft/sq ft · full range 13.2–16.2 brass · 20 mm for slabs and beams, 40 mm for PCC and mass concrete · price it

Bricks10,200 nos

8–9 nos/sq ft · full range 9,600–10,800 nos · Assumes 9" external + 4.5" internal walls; a block-work house needs far fewer · price it

Concrete (total)45.6 cum

0.038 cum/sq ft · full range 45.6–45.6 cum · All grades together — footings, columns, beams and slabs · price it

Paint216 L

0.18 L/sq ft · full range 216–216 L · Two coats + primer on new plaster, inside and out — a 1,000 sq ft house takes ~180 L · price it

Electrical points78 points

55–75 points per 1,000 sq ft · full range 66–90 points · Complete electrical runs 5–7% of the whole-house budget · price it

Water demand (design)675 L/day

135 litres/person/day × 5 people. Size the overhead tank at about one day’s demand plus a fire margin — a 1,000 L tank serves a family of 5–6 comfortably.

Quantities only — this does not cost anything. Pair it with the material bill to price these at today’s rates, and the labour bill for the other half. Thumb rules assume conventional RCC framing at 3–4.5 m spans; unusual geometry drifts off them fast, always upward.

Structural sizing rules

The quick sizes that go with the quantities above. Each links to the calculator that works it out properly — these are starting points, not designs.

  • Slab thicknessspan / 26100–150 mm covers most homes · open the tool
  • Beam depthspan / 12 to span / 15width ≥ 230 mm to match walls · open the tool
  • Column (G+1)230 × 300 mm, M20230 × 380 mm for G+2 · open the tool
  • Foundation depth1.0–1.2 m single, 1.5 m G+1ordinary soil · open the tool
  • Development length~41d (Fe 500, M20)lap length 50d, staggered · open the tool
  • Steel densityslabs 80–90 · beams 110–130 · columns 180–250 kg/cumfootings 60–80 · open the tool

What thumb rules are for, and what they are not. They give you a budget skeleton in fifteen minutes that every later document — quotation, BOQ, running bill — can be nailed against, so you spot when a contractor’s figure has quietly moved before the money is gone. They are not a bar bending schedule and not a substitute for a design. Order against the drawings; use this to know when the drawings, or the bills, look wrong.

Thumb rules & estimation

3

The quick math experienced engineers use.

Materials & components

3

Choosing between types of wood, pipes and structural members.

Budget & property

2

Building affordably and handling society issues.

Career

1

Interview prep for civil engineers.