Estimating raw materials for a house
Before detailed drawings exist, builders use per-square-foot thumb-rules to size their first material order and budget. For an average residential build, every square foot of built-up area needs roughly 0.4 bags of cement, 4 kg of steel, 1.8 cft of sand, 1.35 cft of aggregate and about 8 bricks. So a 1,200 sqft house works out to approximately 480 cement bags, 4.8 tonnes of steel, and 9,600 bricks. These are starting figures, useful for planning deliveries and cash flow, not a substitute for a quantity take-off from drawings.
What drives the numbers
Steel is the most variable: a conservatively designed or multi-storey frame can use well over 4 kg/sqft, while an efficient single-storey design may use less. Cement and aggregate scale with the amount of concrete and plaster, and brick counts depend on wall thickness and layout. The quality setting here nudges all coefficients up or down to reflect lighter or heavier construction.
From estimate to order
Use this figure to plan, then refine: get a structural design, prepare a bar bending schedule for the actual steel (see the BBS calculator), and compute concrete element by element. Order materials in stages tied to your construction sequence rather than all at once, to reduce storage loss and lock-up of cash.