Sunday, December 26, 2010

Thumbrules for Estimating Quantities in Residential Buildings

Expert estimators are able to work out the quantites of concrete, steel, brickwork, plaster and finishing material based on the total built-up area of a residential building without even looking at the building plans.

So here's a rough guide on working out the quantites for a residential building of approx 1 lakh square foot built-up area.

Concrete-  Approx 4500 cum of concrete would be required for the structural frame of the building. The thumrule to follow is 0.045 cum of concrete per square foot of built-up area. This quantity would increase slightly for a building having basements as extra concrete would go in the raft, retaining walls and to the ramps to the basement.

Rebar- Approx 540 tons of rebar would be required. The thumbrule to follow is 120 kg of rebar per cum of concrete. Highrise buildings require more steel in the colums and the amount of steel per cum of concrete would increase with the height of the building.

Brickwork - Approx 1.3 lakh sq feet of wall would be present in the building with 1 lakh square feet area. However, the total area of the walls would depend a lot on the size of rooms.

Plastering and Paint Area - is approximately 3 times of the brickwork area . Note that this also includes ceiling and staircase plastering.

These numbers only apply to large residential towers and not to small housed and bungalows. Please apply these numbers with caution as they may vary for your particular project.