Important Concepts in Estimating & Costing

• According to Indian Standards Institute the actual size of modular bricks is 19 x 9 cm x 9 cm.

• The measurement is made for stone work in square metre in case of – Wall facing, Dressed stones in Chajjas

• The slope of the outlet of ‘P trap’ below the horizontal is kept – 14°

• According to IS method of measurement, the order of the sequence is – Length, Breadth, Height

• The area is measured correct to the nearest – 0.01 sq m

• The main factors to be considered while preparing a detailed estimate are – 1.Quantity of the materials, 2.Availability of materials, 3.Transportation of materials, 4.Location of site and local labour charges.

• The brick work is measured in sq metre in case of – 1.Honey comb brick work, 2.Brick flat soling, 3.Half brick walls or the partition

• The damp proof course (D.P.C) is measured in – Sq. m

• Brick walls are measured in Sq. m if the thickness of the wall is 20 cm.

• Cost of fittings and their fixing is specified for the sanitary fittings — Water closets, Flushing pipes, Laboratory, basins, Sinks

• In case of laying gullies, siphons, intercepting traps, the cost includes – Setting and laying, Bed concreting, Connection to drains

• In long and Short wall method of estimation the length of long wall is the centre to centre distance between the walls and – half breadth of wall on each side.

• The earth work of cutting in trenches or borrow pits in fairly uniform ground is measured with the help of average depths of the dead men.

• The earth work in trenches or borrow pits in irregular ground is measured taking the difference in levels before and after completion of work.

• The height of the sink of wash basin above floor level is kept – 75 cm to 80 cm

• Carpet area does not include the area of – 1.The walls along with doors and other openings, 2.Corridor and passage, 3.Bath room and lavatory, 4.Kitchen and pantry

• The concrete work for the part of the building of specified thickness is measured in square metres – Root slabs, Floors, D.P.c, Wall panels

• The expected out turn for earth work in excavation in ordinary soil per labour per day is 3.00 cum.

• Antisiphonage pipe is connected to – Top of P trap

• The estimated value of the work excluding the amount for contingencies, work charged establishment tool and plants is called work value.

• The actual expenditure involved to complete a work including incidental, establishment and travelling charges is called Actual cost

• The formal acceptance by the administrative department for incurring an expenditure on the work is called Administrative approval.

• The order of a competent authority sanctioning a properly detailed estimate of the cost of a work of construction or repair is called Technical sanction.

• The expected out turn of cement concrete 1 : 2 : 4 per mason per day is 5.0 m³.

• The rate of payment is made for 100 cu m (per % cu m) in case of – Earth work in excavation, Rock cutting, Excavation in trenches for foundation, Earth work in filling the plinth.

• The plinth area of a building not includes the area of cantilevered porch.

• The minimum width of a septic tank is taken – 75 cm

• Lead is the average horizontal straight distance between the borrow pit and the place of spreading soil.

• The lead is calculated for each block of the excavated area.

• The unit of lead is 50 m for a distance up to 500 m.

• Pointing, Plastering, Glazing and Striking are measured in sq.m.

• The item of the brick structure measured in sq.m is – Broken glass coping

• Bends are provided in canals if these are partly in excavation and partly in embankment.

• The items of steel work which are measured in sq.m are Collapsible gates, Rolling shutters, Steel doors, Ventilators and Glazing.

• If the formation level of a highway has a uniform gradient for a particular length and the ground is also having a longitudinal slope the earthwork may be calculated by – 1. Mid-section formula, 2.Trapezoidal formula, 3.Prism0idal formula

• The most reliable estimate is – Detailed estimate

• The volume is measured correct to the nearest 0.01 cum.

• Cement is paid per 50 kg bag.

• Lime is paid per quintal.

• Brick aggregates are paid per cum.

• The earth work is not measured separately in – Setting out of works, Site clearance, Dead men, Steps in deep excavation

• Pipes laid in trenches and pipes fixed to walls are measured separately.

• Cutting through walls and floors are included with the item.

• Pipes are classified according to their sizes and quality.

• In laying pipes the method of Jointing and fixing is specifically specified.

• The earthwork calculation in excavation is made from the difference in levels obtained with a level.

• The earth work in excavation to form the road embankment includes the formation of correct profile and depositing the soil in layers.

• The excavation exceeding 1.5 m in width and 10 sq.m in plan area with a depth not exceeding 30 cm is termed as – Surface excavation

• The unit of measurement is per quintal for the M.S reinforcement of R.C.C works.

• The gully trap collects waste water from the kitchen, sink, wash basins. etc.

• Due to change in price level a revised estimate is prepared if the sanctioned estimate exceeds – 8.0%

• The brick work is not measured in cu. m in case of – Half brick wall

• In the mid-section formula – 1.The mean depth is the average of depths of two consecutive sections, 2.The area of mid-sections is calculated by using mean depth, 3.The volume of the earth work is calculated by multiplying the mid-section area by the distance between the two sections.

• The detention period in a septic tank is assumed as 30 minutes.

• The ‘centre line method’ is specially adopted for estimating – Circular buildings, Hexagonal buildings, Octagonal buildings, Other geometrical shaped buildings

• As per Indian Standard Specifications the peak discharge for domestic purposes per capita per minute is taken – 1.80 litres for 5 to 10 users, 1.20 litres for 15 users, 1.35 for 20 users.

• The item of work not included in the plinth area estimate is courtyard area.

• The items whose weight is added to the weight of respective items are – Cleats, Brackets, Bolts, Distance Separators

• The bent up bars at a support resist the negative bending moment and the sharing force.

• The bending of bars near supports is generally at 45°.

• The usable covered area of the rooms of any storey of a building is called carpet area.

• The carpet area of a building along with area of its kitchen, pantry, store, called floor area.

• The expected out turn of half brick partition wall per mason per day is 2.0 m³.

• The floor area includes the area of the balcony up to 50%.

• The built up covered area at the floor level of any storey of a building is called plinth area.

• The incidental expenses of a miscellaneous character which could not be predicted during preparation of the estimate are called contingencies.

• Additional supervising staff engaged at work site is called work charged establishment.

• Detailed specifications specify qualities, quantities and the proportions of materials to be used for a particular item.

• The cost per unit at which the article can be procured from the open market at a given time is catted ‘Market rate’.

• The expected out turn of brick work in cement mortar in foundation and plinth per mason per day is 1.25 m³.

• The F.S.L. is above N.S.L. the canal is caned partly in cutting and partly in filling.

• The diameter of a domestic sewer pipe laid at gradient 1 in 100 is recommended – 150 mm

• The weight of an item is measured correct to nearest – 1.00 kg

• All pipes and fittings are classified according to their diameters.

• The diameter of the pipe is the normal diameter of internal bore.

• The trap which is provided to disconnect the house drain from the street sewer is called – Master trap, Intercepting trap, Interception manhole, Interceptor chamber.

• The rate of an item of work depends on – Specifications of Works, Specifications of materials, Proportion of mortar, Method of construction

• While preparing a detailed estimate – 1.Dimension should be measured correct to 001 m, 2.Area should be measured correct to 0.01 sq. m

• All pipes are measured along the centre line of the pipes in metres.