House construction cost
Difference of construction cost in Economical and Premium grade Grey structure
Today in our construction guide episode 8 we will be discussing the house construction cost difference between the economical grade and premium grade grey structure. Team Overcs Construction services received immense amount of queries about the builders making grey structures in Rs 1150 sqft including their profit margins where as this is just the cost of grey structure as per the detailed cost guide presented by Team Overcs in September 2017. We would like to make one very important thing clear that grey structure is a very technical task and using low quality material and unskilled labour can cause unrepairable damages to the house. As the major difference between premium and economical grey structure, is using skilful labour and good quality material. We mentioned previously there are 5 major materials used in grey structure, i.e. (bricks, steel, cement, sand and crush). In this article we will be doing a quality comparison of the material used in both economical and premium grade grey structure.
The most important and the most difficult item to choose and compare in grey structure are the bricks. As they do not have any set standard or brand name in Pakistan. Bricks costing from Rs6/- per brick to Rs11/- per brick are considered awal (good). Whereas bricks starting from Rs11/- per brick to Rs15/-per brick are considered special. Previously in our costing we have mentioned bricks of Rs8/- as awal. Whereas if bricks of Rs6/- or Rs7/- are used in the economical grey structure. A massive amount of Rs25/- to Rs30/ per sqft can be saved just by using low quality bricks.
The second most important thing used in grey structure is Steel or reinforcement. It is available both in branded and non branded make with a considerable difference in rate and quality. However it is not the brand that has a significant effect on per square foot cost, it is the quantity according to which reinforcement is used during construction of house. Unfortunately in our local house construction mechanism, structural drawings are not considered as crucial and important mostly. Whereas in reality, these are a set of most important instructions that must be followed in any case. In economical grade grey structure construction steel is used as per on site requirement which comes out to be around 1.25 kgs per sqft of covered area, whereas in premium grade grey structure construction this figure goes up to 2 kgs per sqft since structural drawings and recommendations by structural engineer are strictly followed. Hence approximately Rs 70 /sqft can be saved by not using steel and reinforcement as per the structural drawings.
Third most important material used during construction of grey structure is cement. As it is already explained in our blog under the heading of Cement that forgery in this material is very common, it is very critical to make sure that cement used during construction is genuine and not fake. However even if genuine cement is used in both grades of construction, what effects the cost is the mortar and concrete ratios in brickwork, plaster and slab pouring. Recommended ratios in premium grade are 1:5(brickwork), 1:4(plaster), 1:3:6(PCC) and 1:2:4(RCC) however in economical grade ratios used are mostly 1:7(brickwork), 1:6(plaster), and 1:4:8(PCC). Another important step where cost can be saved is the thickness of slabs. In economical grade slab thickness is generally kept around 4.5 inches whereas in premium grade construction, thickness of slabs are strictly maintained around 6 inches as recommended by the structural engineer. By following the non recommended ratios and slab thickness of economical grade, a figure of around Rs 40 per sqft can be saved from the overall construction cost.
Sand is another material in which cost can be saved. Let us take example of house construction in Lahore where two kinds of sands are available, ravi and chenab. Sand extracted from river ravi is of inferior quality with mud mixture and is cheap in price as compared to chenab which is considered as fine sand both for brickwork, plaster and concrete. Hence a figure of around 15 Rs per sqft can be saved by using ravi sand throughout the house construction process.
Another material that has significant importance during construction of grey structure is course aggregate or crush. It should be of fine, hard and in shape quality e.g, crush available in Lahore are Sardogha local, Rohi, Sargodha plant, Sargodha special and Margalla. Crush such as sargodha local and rohi are cheap in price and of inferior quality due to their soft characteristics and are not recommended for quality constructions. By using low quality course aggregate, an amount of Rs 20 per sqft can be saved from the overall construction cost.
Hence by using low quality material, a sum of Rs 150 to 200 per sqft can be saved from the overall house construction cost whereas another 100 Rs per sqft can be saved by using low quality labor and not following technical specifications most important of which are the foundation depths, slab thickness and PCC thickness. By doing so, overall per square feet figure of cost can come down to Rs 850 to 950/sqft of covered area however at the expense of heavily compromised quality.