Cost and Quantity Estimation

 

CHAPTER-1   INTRODUCTION TO ESTIMATION AND COSTING Introduction For all engineering works it is required to know beforehand the probable cost of construction is known as the “Estimated Cost”. If the estimated cost is greater than the money available, then attempts are made to reduce the cost by reducing the work or by changing the specifications. From this the importance of estimate for engineers may be understood. In preparing an estimate, the quantities of different items of work are calculated by simple mensuration method and from these quantities the cost is calculated. The subject of estimating is simple, nothing much to understand, but knowledge of drawing is essential. In preparing an estimate one has to go into the details of each item,  big or small, nothing can be left or missed. Estimating makes one through, superficial work does not do, and one has to go deep into details. There is no hard and fast rule for finding out the dimensions from the drawings (plans, elevations, sections, etc.) but for quick certain principles may be followed. An estimator should picture the object (Building, structure, etc.) in his mind from the study of drawings and specifications. Our building is a G+3 Residential building located at Kukatpally Housing Board colony, phase IV, Hyderabad, 500072. Its land area is up to 260.13 sq.m., where it has got all the facilities like easy transport and scarce water. It is a place where the promoter can make a good amount of profit for his construction of work. The soil strength is good enough so that we don't have to go for deep foundations. We need to estimate the cost which is going to be incurred while during the construction of this building. In order to estimate the cost of a building we need to segregate the building into various item of work and a nd to quantify it.

Objective Objective is to quantify and arrive the cost of the project with minimum profit which is going to be incurred by the promoter for the construction of G+3 Residential building. 1

 

1.1 Definition of estimating Estimating is the technique of calculating or computing the various quantities and the expected Expenditure to be incurred on a particular work or project. In case the funds available are less than the estimated cost the work is done in part or by reducing it or specifications are altered, the following requirement are necessary for  preparing an estimate. a) Drawings like plan, elevation and sections of important impo rtant points.  b) Detailed specifications about workmanship & properties of materials etc. c) Standard schedule of rates of the current cu rrent year.

1.2 Need for estimation 1. Estimate gives an idea of the cost of the work and hence its feasibility can be determined i.e. whether the project could be taken up with in the funds available or not. 2. Estimate gives an idea of time required for the completion of the work. 3. Estimate is required to invite the tenders and Quotations Q uotations and to arrange contract. 4. Estimate is also required to control the expenditure ex penditure during the execution of work. 5. Estimate decides whether the proposed plan matches the funds available or not.

1.3 Procedure of estimating or method of estimating. Estimating involves the following operations 1. Preparing detailed Estimate. 2. Calculating the rate of each unit of work 3. Preparing abstract of estimate

1.4 Data required to prepare an estimate 1. Drawings i.e. plans, elevations, sections etc. 2. Specifications 3. Rates

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1.4.1 Drawings If the drawings are not clear and without complete dimensions the preparation of estimation become very difficult. So, it is very essential before preparing an a n estimate.

1.4.2. Specifications

a) General Specifications: This gives the nature, quality, class and work and materials in general terms to be used in various parts of wok. It helps no form a general idea of  building.  b) Detailed Specifications: These gives the detailed description of the various items of work laying down the Quantities and qualities of materials, their proportions, the method of preparation workmanship and execution of work.

1.4.3. Rates For preparing the estimate the unit rates of each item it em of work are required. 1. For arriving at the unit rates of each item. 2. The rates of various materials to be used in the construction. 3. The cost of transport materials. 4. The wages of labour, skilled or unskilled of masons, carpenters, Mazdoor, etc.

1.5 Lumpsum While preparing an estimate, it is not possible to work out in detail in case of  petty items. Items other than civil engineering such items are called lumpsum items or simply L.S.Items. The following are some of L.S. Items in the estimate. 1. Water supply and sanitary arrangements. 2. Electrical installations like meter, motor, etc., 3. Architectural features. 4. Contingencies and unforeseen items.

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In general, certain percentage on the cost of estimation is allotted for the above L.S.Items Even if sub estimates prepared or at the end of execution of work, the actual cost should not exceed the L.S.amounts provided in the main estimate.

1.6 Complete Estimate  Most of the people think that estimate of a structure includes cost of land, cost of materials and labour. But many other direct and indirect costs included and are shown  below

The complete estimate

Cost of land

P.S & contingencies at 5%

legal expenses

Actual cost Cost of Cost of Brochorage of land Surveying verification and execution of deeds

cost of structure

Cost of Cost of Consulting Permit fee materials labour Engineers fee for water, electricity

cost for cost for  preparation of supervision  plan, estimate and design

Figure 1: Complete Estimate

1.7 Work charged establishment establishment:: During the construction of a project considerable number of skilled supervisors, work assistance, watch men etc., are employed on temporary basis. The salaries of these  persons are drawn from the L.S. amount allotted towards the work charged establishment. That is, establishment which is charged directly to work. An L.S.amount of 1½ to 2% of the estimated cost is provided towards the work charged ch arged establishment.

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CHAPTER-2  

MEASUREMENT OF MATERIALS AND WORKS

2.1 Units of measurements The units of measurements are mainly categorized for their nature, shape and size and for making payments to the contractor and also. The principle of units of measurements normally consists the following: a) Single units work like doors, windows, trusses the etc., are expressed ex pressed in numbers.  b) Works consists linear measurements involve length like cornice, fencing, hand rail,  bands of specified width etc., are expressed in (RM) c) Works consists areal surface measurements involve area like plastering, white washing,  partitions of specified thickness etc., are expressed in square meters (m2) (m2) d) Works consists cubical contents which involve volume like earthwork, cement concrete, Masonry etc are expressed in Cubic meters.

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Table 1: Units of Measurement

S.No 1

Particulars of items

Units of Units of measurement  payment

Earth work: 1. Earth work in Excavation 2. Earthwork in filling in foundation trenches 3. Earth work in filling in plinth

cum

Per%cum

cum cum

Per%cum Per%cum

cum cum cum cum

 percum  percum  percum  percum

sqm cum

 persqm  per cum

Width & Height)

cum

1rm

3

Damp Proof Course (D.P.C): (Thickness should be mentioned)

sqm

 persqm

4

Brick work: 1. Brickwork in foundation 2. Brick work in plinth 3. Brick work in super structure 4. Thin partition walls 5. Brick work in arches 6. Reinforced brick work

cum cum cum sqm cum cum

 per cum  per cum  per cum  per cum  per cum  per cum

cum

 per cum

2

Concrete: 1. Lime concrete in foundation 2. Cement concrete in Lintels 3. R.C.C.in slab 4. C.C. or R.C.C. Chujja, Sunshade 5. L.C. in roof terracing (thickness specified) 6. Cement concrete bed 7. R.C. Sunshade (Specified

(R.B.Work) 5

6

Stone Work: Stone masonry Wood work: 1. Doors and windows frames or chowkhats, rafters & beams 2. Shutters of doors and windows (thickness specified) 3. Doors and windows fittings (like hinges, tower bolts, sliding bolts, handles)

6

cum

 per cum

sqm

 per sqm

 Nos.

 per Nos.

 

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Steel work 1. Steel reinforcement bars etc in R.C.C. and R.B.work. 2. Bending, binding of steel Reinforcement 3. Rivets, bolts, & nuts, Anchor bolts, Lewis  bolts, Holding down bolts. 4. Iron hold fasts 5. Iron railing (height and types specified) 6. Iron grills

Quintal Quintal

 per quintal  per quintal

Quintal Quintal Quintal Sqm

 per quintal  per quintal  per quintal  per sqm

cum

 per cum

sqm sqm sqm

 per sqm  per sqm  per sqm

sqm sqm

 per sqm  per sqm

sqm

 per sqm

sqm sqm

 per sqm  per sqm

sqm sqm

 per sqm  per sqm

mortar plain)

sqm

 per sqm

11

Rain water pipe /Plain pipe

1RM

 per RM

12

Steel wooden trusses

1No

 per 1No

13

Glass panels(supply)

sqm

 per sqm

14

Fixing of glass panels or Cleaning

 Nos.

 per Nos.

8

9

10

Roofing 1. R.C.C. and R.B.Slab roof (excluding steel) 2. L.C. roof over and inclusive of tiles or  brick or stone slab etc (thickness specified) 3. Centering and shuttering form work 4. A.C.Sheet roofing Plastering, points finishing 1. Plastering-Cement or Lime Mortar (thickness and proportion specified) 2. Pointing 3. White washing, colour washing, cement wash (number of coats specified) 4. Distempering (number of coats specified) 5.Painting, varnishing(no of coats specified) Flooring: 1. 25mm cement concrete over 75mm lime concrete floor (including L.C.) 2. 25mm or 40mm C.C. floor 3. Doors and window sills (C.C. or cement

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2.2 Rules for measurement The rules for measurement of each item are invariably described in IS- 1200. However some of the general rules are listed below. belo w. 1. Measurement shall be made for finished item of work and description of each item shall include materials, transport, labour, fabrication tools and plant and all types of overheads for finishing the work in required shape, size and specification. 2. In booking, the order shall be in sequence of length, breadth and height or thickness. 3. All works shall be measured subject to the following tolerances. i) Linear measurement shall be measured to the nearest ne arest 0.01m. ii) Areas shall be measured to the nearest 0.01 sq.m iii) Cubic contents shall be worked-out to the nearest 0.01 cum 4. Same type of work under different conditions and nature shall be measured separately under separate items. 5. The bill of quantities shall fully describe the materials, proportions, workmanships and accurately represent the work to be executed. 6. In case of masonry (stone or brick) or structural concrete, the categories shall be measured separately and the heights shall be described: d escribed: a) From foundation to plinth level  b) From plinth level to first floor level level c) From First floor to second floor level and so on.

2.3 Methods of taking out quantities The quantities like earth work, foundation concrete, brickwork in plinth and super structure etc., can be workout by b y any of following two methods: 2.3.1 Long wall - short wall method 2.3.2 Centre line method. 2.3.3Partly centre line and short wall method.

2.3.1 Long wall-short wall method

In this method, the wall along the length of room is considered to be long wall while the wall perpendicular to long wall is said to be short wall. To get the length of 8

 

long wall or short wall, calculate first the centre line lengths of individual walls. Then the length of long wall, (out to out) may be calculated after adding half breadth at each end to its centre line length. Thus the length of short wall measured into in and may be found by deducting half breadth from its centre line length at each end. The length of long wall usually decreases from earth work to brick work in super structure while the short wall increases. These lengths are multiplied by breadth and depth to get quantities.

2.3.2 Centre line method

This method is suitable for walls of similar cross sections. Here the total centre line length is multiplied by breadth and depth of respective item to get the total quantity at a time. When cross walls or partitions p artitions or verandah walls join with main wall, the centre line length gets reduced by half of breadth for each junction. Such junction or joints are studied carefully while calculating total centre line length .The estimates prepared by this method are most accurate and quick. 2.3.3 Partly centre line and partly cross wall method

This method is adopted when external (i.e., all-round the building) wall is of one thickness and the internal walls having different thicknesses. In such cases, centre line method is applied to external walls and long wall-short wall method is used to internal walls. This method suits for different thicknesses walls and different level of foundations. Because of this reason, all Engineering departments are practicing this method.

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CHAPTER-3

TYPES OF ESTIMATES

3.1 Detailed estimate The preparation of detailed estimate consists of working out quantities of various items of work and then determines the cost of each item. This is prepared in two stages.

i) Details of measurements and calculation of quantities

The complete work is divided into various items of work such as earthwork concreting, brick work, R.C.C. Plastering etc. The details of measurements are taken from drawings and entered in respective columns of prescribed Performa. The quantities are calculated by multiplying the values that are in numbers Column to Depth column as shown below:

Table 2: Details of measurements form:

S.No

Description

Nos.

Length

Breadth

Depth/

(L)

(B)

Height

M

m

(D/H) m

of Item

Quantity

Explanatory Notes

ii) Abstract of Estimated Cost

The cost of each item of work is worked out from the quantities that already computed in the details measurement form at workable rate. But the total cost is worked out in the prescribed form is known as abstract of estimated form.4%of estimated Cost is allowed for Petty Supervision, contingencies and Unforeseen items. 10

 

Table 3: Abstract Estimate Form:

Item No.

Description/ Particulars

Quantity

Unit

Rate

Per (Unit) 

Amount

The detailed estimate should accompanied with i) Report ii) Specification iii) Drawings (plans, elevation, sections) iv) Design charts and calculations v) Standard schedule of rates. 3.1.1. Factors to be considered While Preparing Detailed Estimate:

i) Quantity and transportation of materials: For bigger project, the requirement of materials is more. Such bulk volume of materials will be purchased and transported definitely at cheaper rate. ii) Location of site: The site of work is selected, such that it should reduce damage or in transit during loading, unloading, stocking of materials. iii) Local labour charges: The skill, suitability and wages of local laborers are considered while preparing the detailed estimate.

3.2 Data  The process of working out the cost or rate per unit of each item is called as Data. In preparation of Data, the rates of materials and labour are obtained from current standard scheduled of rates and while the quantities of materials and labour required for one unit of item are taken from Standard Data Book (S.D.B)

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3.2.1 Fixing of Rate per Unit of an Item:

The rate per unit of an item includes the following: i) Quantity of materials & cost: The requirements of materials are taken strictly in accordance with standard data book (S.D.B). The cost of these includes first cost, freight, insurance and transportation charges. ii) Cost of labour: The exact number of labourers required for unit of work and the multiplied by the wages/ day to get of labour for unit item work. iii) Cost of equipment (T&P): Some works need special type of equipment, tools and  plant. In such case, an amount of 1 to 2% of estimated cost is provided. iv) Overhead charges: To meet expenses of office rent, depreciation of equipment

salaries of staff postage, lighting an amount of 4% of estimate cost is allocated.

3.3 Methods of preparation of approximate estimate Preliminary or approximate estimate is required for studies of various aspects of work of project and for its administrative approval. It can decide, in case of commercial  projects, whether the net income earned justifies the amount invested or not. The approximate estimate is prepared from the practical knowledge and cost of similar works. The estimate is accompanied by a report duly explaining necessity and utility of the  project and with a site or layout plan. A percentage 5 to 10% is allowed for contingencies. The following are the methods used for preparation of approximate estimates. 3.3.1 Plinth area method 3.3.2 Cubical contents methods 3.3.3 Unit base method.

3.3.1 Plinth area method:

The cost of construction is determined by multiplying plinth area with plinth area rate. The area is obtained by multiplying length and breadth (outer dimensions of  building). In fixing the plinth area rate, careful observation and necessary enquiries are made in respect of quality and quantity q uantity aspect of materials and labour, type of foundation, height of building, roof, wood work, fixtures, number of storey’s store y’s etc., 12

 

As per IS 3861-1966, the following areas include while calculating the plinth area of building.

a) Area of walls at floor level.  b) Internal shafts of sanitary installations not exceeding 2.0m2, lifts, air-conditioning ducts etc., c) Area of barsati at terrace level: Barsati means any covered space open on one side constructed on one side constructed on terraced roof which is used as shelter during rainy season. d) Porches of non cantilever type. Areas which are not to include

a) Area of lofts.  b) Unenclosed balconies. c) Architectural bands, cornices etc., d) Domes, towers projecting above terrace level. e) Box louvers and vertical sun breakers.

3.3.2 Cubical Contents Method: 

This method is generally used for multistoried buildings. It is more accurate that the other two methods viz., plinth area method and unit base method. The cost of a structure is calculated approximately as the total cubical contents (Volume of buildings) multiplied by Local Cubic Rate. The volume of building is obtained by Length x breadth x depth or height. The length and breadth are measured out to out of walls excluding the  plinth off set. The cost of string course, cornice, corbelling etc., is neglected. The cost of building= volume of buildings x rate/ unit volume.

3.3.3 Unit Base Method: 

According to this method the cost of structure is determined by multiplying the total number of units with unit rate of each item. In case schools and colleges, the unit considered to be as 'one student' and in case of hospital, the unit is 'one bed'. the unit rate is calculated by dividing the actual expenditure incurred or cost of similar building in the nearby locality by the number of units. 13

 

CHAPTER-4 MAIN ITEMS OF WORK 4.1 Earthwork Earthwork in excavation and Earthwork in filling are taken out separately under different items, and quantities are calculated in cu m. Foundation trenches are usually dug to the exact width of foundation with vertical sides. Earth in excavation in foundation is calculated by taking the dimensions of each trench length x breadth x depth. Filling in trenches after the construction of masonry is ordinarily neglected. If the trench filling is accounted, this may be calculated by deducting the masonry from the excavation. Earthwork in plinth filling is calculated by taking by taking the internal dimensions in between plinth wall (length x breadth) which are usually less than the internal dimensions of the room by b y two off-sets of plinth wall i.e. 10 cm (4.5”) and height is taken after deducting the thickness of concrete in floor, usually 7.5cm (3”). If sand filling is done in plinth, this should be taken separately. The length and breadth for each filling may be same as the internal dimensions of the room if there is no off-set in plinth wall. Excavated earth is used in trench filling and plinth filling and usually not paid for separately, but may also be included under a separate item  –   “Return fill and ram or  backfill” and paid at a lesser rate .Extra earth if required for filling is brought from outside. If there is surplus earth after trench and plinth filling, this may be utilized in leveling and dressing of site or carted away and removed.

4.2 Concrete In Foundation  The concrete is taken out in cu m by length x breadth x thickness. The length and  breadth of foundation concrete are usually the same as for excavation, only the th e depth or thickness differs. The thickness of concrete varies from 20 cm to 45 cm, usually 30 cm (9” to 18”, usually 12”). Foundation concrete consists of lime concrete or weak cement concrete.

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PCC –  PCC  –  Plain  Plain Cement Concrete:

After the process of excavation, laying of plain cement concrete that is PCC is done. A layer of 100mm was made in such a manner that it was not mixed with the soil. It provides a solid base for the foundation and a mix of 1:4:8 that is, 1 part of cement to 4  parts of fine aggregates and 8 parts of coarse aggregates a ggregates by volume were used in it. Plain concrete is vibrated to achieve full compaction. Concrete placed below ground should be protected from falling earth during and after placing. Concrete placed in ground containing deleterious substances should be kept free from contact with such a ground and with water draining there from during placing and for a period of seven days.

Figure 2: P.C.C

4.3 Soling When the soil is soft or bad, one layer of dry brick or stone soling is applied  below the foundation concrete. The soling layer is computed in sq m (Length x Breadth) specifying the thickness.

4.4 Damp Proof Course  D.P.C. usually of 2.5 cm (1”) thick rich cement concrete 1:1.5:3 or 2 cm, (3/4”) thick rich cement mortar 1:2, mixed with standard waterproofing material, is provided at the plinth level to full width of plinth wall , and the quantities are computed in sq m, (Length x Breadth). Usually D.P.C. is not provided at the sills of doors veranda openings, for which deductions are made. (One kg of Cem-seal or impermo or other standard waterproofing compound per bag of cement is generally used). 

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4.5 Masonry  Masonry is computed in cu m (Length x Breadth x Height). Foundation and plinth masonry is taken under one item, and masonry in superstructure is taken under a separate item. In storied building the masonry in each story as ground floor above plinth level, first floor, etc. is computed separately. In taking out quantities the walls are measured as solid and then deductions are made for openings as doors, windows, etc. and such other  portions as necessary. Masonry of different types or classes, masonry with different mortar, etc. are taken out under separate items.

4.6 Lintels Over Openings Lintels are made of R.C.C or R.B., quantities are calculated in cu.m. Length of the lintel is equal to the clear span plus span  plus two bearings. If dimension of bearings are not given the bearing may be taken as same as the thickness of lintel with a minimum of 12cm (4.5”).

4.7 R.C.C and R.B. work   R.C.C and R.B work may be in roof or floor slab, in beams, lintels, columns, foundations, etc. and the quantities are calculated in cu m. Length, breadth and thickness are found correctly from the plan, elevation, and section or from other detailed drawings. Bearings are added with the clear span to get the dimensions. The quantities are calculated in cu m exclusive of steel reinforcement and its being but inclusive of centering and shuttering and fixing and binding reinforcement in position. The reinforcement including it’s taken up separately under steel, if other details are not given. The volume of steel is not required to be deducted from the R.C.C. or R.B. Columns:

Columns are the vertical members which are used to transfer the loads from the roof beams to the footings. Based on the loads different sizes of columns are designed. The various sizes of columns are used in our site those are 750x400, 400x600, 250x900, 230x300mm etc. 

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Roof Beams:

Roof beams are horizontal members which transfers the loads from the slab to columns. Based on the loads different sizes of roof beams are designed. The various sizes of roof beams are used in our site those are 400x600, 400x750, 250x750mm etc. Slabs:

Slab covers over roof beams which can take the live loads and transfers it to the roof beams. Generally the slabs are divided into two categories. When the ratio of long span to short span is greater or equal to 2 then the slab is known as single way slab, when the ratio of long span to short span is less than 2 then the slab is known as two way slabs.

R.C.C and R.B. work may also be estimated inclusive of steel and centering and shuttering for the complete works, if specified. Centering and shuttering (from work) are usually included in the R.C.C or R.B. work, but may also be taken separately in sq m of surface in contact with concrete. In R.C.C work plastering is not taken separately, but the exposed surface are finished with thin rich cement sand mortar plastering to give smooth smooth and even even surface , which usually is not taken into consideration. Reinforcement:

Steel reinforcements are used, generally, in the form of bars of circular cross section in concrete structure. They are like a skeleton in human body. Plain concrete without steel or any other reinforcement is strong in compression but weak in tension. Steel is one of the best forms of reinforcements, to take care of those stresses and to strengthen concrete to bear all kinds of loads. Grade Fe 415 is being used most commonly nowadays. This has limited the use of plain mild steel bars because of higher yield

stress and bond strength resulting in saving of steel quantity. Some companies

have brought Thermo Mechanically Treated (TMT) and Corrosion Resistant Steel (CRS)  bars with added features. Among these types we used TMT bars in our construction. 17

 

Figure 3: Slab Reinforcement

Terms Used In Reinforcement: Bar-bending-schedule

Bar-bending-schedule is the schedule of reinforcement bars prepared in advance before cutting and bending of bars. This schedule contains all details of size, shape and dimension of bars to be cut. Lap length

Figure 4: Lap Joint

Lap length is the length overlap of bars tied to extend the reinforcement length. Lap length is about 50 times the diameter of the bar is considered safe. Laps of neighboring bar lengths should be staggered and should not be provided at one level/line. 18

 

At one cross section, a maximum of 50% bars should be lapped. In case, required lap length is not available at junction because of space and other constraints, bars can be  joined with couplers or welded (with correct choice of method of welding).

Anchorage Length

This is the additional length of steel of one structure required to be inserted in other at the junction. For example, main bars of beam in column at beam column  junction, column bars in footing etc. The length requirement is similar to the lap length mentioned in previous question or as per the design instructions

Figure 5: Anchorage Cover Block

Cover blocks are placed to prevent the steel rods from touching the shuttering plates and thereby providing a minimum cover and fix the reinforcements as  per the design drawings.

The cover blocks used for different individuals are: Footings 

40mm

Beams 

25mm

Columns 

40mm

Retaining wall 

25mm for earth face

Slabs 

15mm

20mm for other face 19

 

Figure 6: Cover Block  

4.8 Flooring and Roofing  The base lime concrete and floor finishing of C.C. or stone or (i) Ground Floor –  The Marble or Mosaic, etc. are usually taken as one job or one item (combined in one item) and the quantity is calculated in sq m multiplying the length and breadth. The length and  breadth are measured as inside dimensions of wall to wall of superstructure. Both the works of base concrete and floor finishing are paid under one item. (ii) First floor, Second floor, etc.   –  –  Supporting  Supporting super structure is taken separately

is cu.m. as R.C.C., R.B. etc.. and the floor finishing is taken separately in sq m as 2.5 cm or 4 cm C.C. (Cement Concrete) or marble or Mosaic, etc. if a cushioning layer of lime concrete is given in between the slab and the floor, the cushioning concrete may be measured with the floor under one item or taken tak en separately. (iii) Roof   –  –   Supporting Supporting structure is taken separately in cu.m and the lime concrete terracing is computed in sq. M with thickness specified, under a separate item including surface rendering smooth. The compacted thickness of lime concrete terracing is 7.5 cm to 12 cm. L.C. terracing may also be calculated in cu m with average thickness.

4.9 Plastering and Pointing Plastering usually 12mm (0.5”) (0.5”) thick is calculated in sq m. For walls the measurements are taken for the whole face of the wall for both sides as solid, and deductions for openings are made. Plastering of ceiling of 12mm thick is computed in sq 20

 

m under a separate head as this work is done with rich cement mortar. For R.C.C work usually no plastering is allowed but for fair finish a thin plaster of rich cement mortar may be allowed which should not be taken in the measurement separately. Pointing  –   Pointing in walls is calculated in sq m for whole surface and deductions

similar to plastering are made.

4.10 Columns Columns are the vertical members which are used to transfer the loads from the roof beams to the footings. Based on the loads different sizes of columns are designed. The various sizes of columns are used in our site those are 750x400, 400x600, 250x900, 230x300mm etc.

4.11 Doors and Windows –  Windows – Wood Wood Work- Chowkhat or Frame  Door and window frames or Chowkhats are computed in cu.m. Length is obtained  by adding all the members of the chowkhat, top and two verticals if there is no sill member, and adding bottom also if there is sill, and the length is multiplied by the two dimensions of the cross section of the member.

4.12 White washing or Colour Washing or Distempering and Painting  The quantities are computed in sq m and are usually same as for plastering. The inside is usually white washed or distempered and this item will be same as for inside  plaster. The outside is colour washed and the quantities of colour washing will be same as for the outside plaster. Number of coats of white washing or colour washing is taken as one job or work and the rates cover for number of coats which should not be multiplying factor. The number of coats should be mentioned in the item. Deductions are dealt in the same manner as for plastering. Painting or Varnishing of doors and windows are computed in sq m, the dimensions should be taken for outer dimensions of the chowkhat i.e., outer dimensions of doors and windows. The area is measure flat. No separate measurement is tak taken en for the chowkhat, the area is same as the area of opening. 21

 

The methods of measurement of white washing, colour washing, distempering and painting of building surfaces in civil engineering en gineering works.

The following rules are to be followed: 1 Clubbing of Items

Items may be clubbed together provided these are on the basis of detailed description of item, stated in this standard. 2 Booking of Dimensions

In booking of dimensions the order shall be consistent and generally in the sequence of length, breadth or width and height. 3 Descriptions of Items

Description of each item shall unless otherwise stated, be held to include, where necessary, conveyance; delivery; handling; unloading; stor ing; ing; waste; return of packing’s; necessary scaffolding; protective cover; and cleaning stains from floors, walls, glass  panes, etc. 4 Bills of Quantities

Item of work shall fully describe materials and workmanship, and accurately represent the work to be executed. 5 Numbers of Coats

Decorative treatment shall be fully described stating the number of coats in each case.  6 Preparatory Works 

Preparatory work, such as brooming down, steel wire brushing, scrapping washing and rubbing down, shall be described and included in the main item. Preparatory work on new surfaces and primary coats, if any, shall be described and included in the main item. 7 Classifications

Various decorative treatments shall be measured separately under the various classifications as given below and materials and type of surfaces to be treated shall be fully described:

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a) Whitewash, colour wash, etc;  b) Non-washable distemper; c) Washable distemper; d) Waterproof paint (colour/colourless); e) Chalk whiting to cloth or hessian surface; f) Linseed oil and cement to steel and an d iron work; and g) Cement slurry wash. Priming and alkali neutralizing treatments, scrapping of surface, washing surfaces spoilt by smoke soot, removal of oil and grease spots, treatment for disinfection with efflorescence, moulds moss, fungi, algae and kitchen shall be b e measured separately and materials described. 8 Walls, Ceilings, etc.  

Work on walls, ceilings and sloping roofs shall each be b e measured separately. 9 Old Treated Surfaces

Work on old treated surfaces shall be measured mea sured separately and so described.

4.13 Lump-sum Item  Sometimes a lump-sum rate is provided for certain small items for which detailed quantities cannot be taken out easily or it takes sufficient time to find the detail, as front architectural or decoration work of a building, fire-place, site cleaning cleanin g and dressing etc.

4.14 Electrification, Sanitary and Water supply Works  For Sanitary and Water supply works 8% and for electrification 8% of the estimated cost of the building works are usually provided in estimate. 

23

 

CHAPTER-5   RATE ANALYSIS

5.1 Definition  In order to determine the rate of a particular item, the factors affecting the rate of that item are studied carefully and then finally, a rate is decided for that item.This process of determining the rate of an item is termed as the analysis of rate or rate analysis.

5.2 Purposes of rate analysis Following are the two main purposes of carrying out the rate analysis of an item : 1.  To determine the actual cost per unit un it of item ; and 2.  To examine the item for economic processes and economic uses of materials involved in making the item.

5.3 Factors affecting Rate Analysis The factors which affect the rare analysis of an item can broadly be divided into the following two categories. 1.  Major factors 2.  Minor factors

1. 

Major factors :  There are mainly two factors on which the rate of an item depends namely.

i) 

Materials

ii) 

Labour Hence, in ordinary procedure of rate analysis, only these two forces are taken into

account and the rate of an item is derived. The points to be remembered for these two factors will now be briefly mentioned.

24

 

Materials :The quantities of various materials required for the construction of an item

can be easily worked out by knowing the specification of that item.The prices of various materials required are fixed. But their prices are variable from place to place and from time to time as they depend on the prevailing market conditions. Hence, before starting the rate analysis of an item, it is essential to collect the prices of such materials from the market at that instant. It is the duty of the person framing the rate analysis to see that the materials available in the market are in accordance with the specification of the item. It is also necessary to include a certain percentage for waste of all materials to cover breakages, losses, cutting waste, etc .However , the average percentage to be adopted for wastage will vary for different trades and operations. With the help of the quantities of various materials and  prices of the materials, the cost of materials for a particular item can be calculated. Labour:  The labour force will will be necessary to arrange arrange the materials in a proper way so so that the item can be completed. For instance, heaps of bricks, cement and sand cannot be

used in the construction of brickwall, unless some masons, coolies and bhisties are available. The amount of labour force required to carry out a unit of a particular item is decided from the past experience or in case of a complicated item, it is decided by carrying out a sample of that item. In any case , it is quite clear that the labour force required will depend on the efficiency of the labourers and hence, this force will be variable from place to place also, the price or wage of labour is a variable factor and will vary from place to place, person to person and time to time.Hence the efficiency of the labourer and the wage of the labourer should be properly studied before starting the rate analysis for a particular item, By knowing the amount of labour force and the wage of labourer, the cost of labour of a particular pa rticular item is calculated. 2) Minor factors: These are the factors which come into force under special

circumstances and should, therefore, be given proper weight, when such conditions are to exist following are some of such factors.

25

 

i) Special equipment :  If the execution of an item requires the use of some special

equipment or plant, the cost of using such special equipment on the rental basis should be included in the rate analysis of that item. ii) Place of work :   The site of work will also have some effect on the rate of an item

under certain conditions. If it is too far, more amount will have to be spent on carting similarly, if it is situated in a highly congested area, it will not be possible to take the materials directly to the site. The materials will have to be stacked on the main road and then they will have to be taken in hand –  hand  – lorries. lorries. This will increase the cost of transport of the materials and consequently, the rates of the items are to be modified. iii) Nature of work : If the work consist of large quantities of the items , the rates may be

less and vice versa. iv) Conditions of contract : If the conditions of contract are very stiff, the rates of the

various items will be high and vice versa. v) Profit of the contractor :  The usual percentage of the profit of the contractor is ten.

But if it is more or less, the rate of the item will be correspondingly affected. The profit of the contractor will includes his overhead charges also. These overhead charges are to  be reasonably ascertained and suitably allocated to various jobs carried out o ut concurrently  by the contractor. The overhead expences can broadly be divided into two categories. a)  Expenses relating to the works such as expenses incurred for tools, testing , supervision , insurance , amenities at site, power, plant , stores , etc.  b)  Expenses relating to the office establishment such as expenses incurred for postage , rent , travelling, satisfactory, taxes, telephone, etc. vi) Specifications :If the specifications of work provide for rigid type tolerances and

superior quality turn out, the rates will be on the higher h igher side. vii) Site conditions : If the site conditions are such that difficulties will be experienced

during execution of work, such as foundations involving water troubles, the rates will be on the higher side, on the other hand, if site conditions are ideally suited for the construction activities, the contractor may quote slightly lower rates . 26

 

viii) Miscellaneous : The other remaining miscellaneous factors affecting rates of items

include time of completion of the project, climatic conditions , reproduction of the contracting firm, discipline of the organization , etc. From the above discussion, it is clear that the accuracy of rate analysis will depend on the skill, knowledge, experience, precision and judgement of the person entrusted with the work of rate analysis.

5.4 Importance of Rate Analysis The process of rate analysis gives a clear picture of various forces acting behind the performance of a particular item. It should be remembered that the rate analysis of any item is never complete, for instance, in the rate analysis of brickwork, a definite rate for bricks is assumed. But this rate for bricks is derived by the manufacturer of bricks by his own rate analysis for preparing bricks. Thus, theoretically, the rate analysis of an item is incomplete, but in practice, it it serves as a useful guide to arrive at a reasonable rate for a particular item.

5.5 Essentials of Rate Analysis For arriving t the correct rate analysis of a particular item, the following essentials are necessary for the person carrying out the rate analysis. an alysis. 1)  Good knowledge of construction work and familiarity with the trade. 2)  Information regarding costs of materials, labour and equipment and 3)  Output of labourer i.e. task works per day da y for various trades.

5.6 Schedule of Rates A schedule or list of rates of various v arious items is prepared after the anal analysis ysis of rates of these items. Such a document is known as the schedule of rates or S.O.R. It is prepared  by large la rge concerns or public bodies. It becomes be comes very v ery useful, especially deciding the rate of an extra item, carried out by b y the contractor.

27

 

 Normally, a clause in the conditions of co contract ntract is inserted, stating that , any extra item that might occur during the execution of the work shall be paid as per rate in the schedule of rates. In some cases, the contractor may be asked to submit his tender by simply quoting the percentage above or below the S.O.R for carrying out the construction work. The schedule of rates consists of groups of items such as demolishing items, excavation items, concrete items, brickwork items, etc. and also information, regarding the present wages of labour and prices of different items , is given in it. As the rates of items mentioned in the schedule of rates are likely to vary, the schedule of rates is periodically revised, usually after three years. The Central Public Works Department ( CPWD ) if the premier construction organisation of the Govt.of India and it has been responsible for the planning and design, construction and maintenance of a variety of building projects like mass housing complexes, hospitals, educational institutions , sport complexes, highways, airports, industrial buildings, bridges, etc. Hence, the schedule of rates serves as an important document for the CPWD. The CPWD schedule of rates contains the basic rates of materials, labour, Carriage etc. of about 2500 items and the finished rates of about 3000 items of work covered under different subheads like building work, road work, water supply and drainage items etc. The rates of the finished items are worked out by the analysis of rates with the standard requirements of material, labour and necessary sundries like water char ges, ges, contractor’s profit, etc.  etc.   Due to continuous changes in the market rates of materials, wages of labour, cost of carriage ,etc. the schedule of rates document requires revision frequently. The updating of this document manually proved to be extremely difficult task, as it involved careful analysis and thorough checking of several of items in the schedule. The use of computers was found to be an ideal solution in the preparation and quick updating of this document in minimum possible time without any chance of human errors. 28

 

The CPWD has evolved the coding procedure and file organization of the computer programme for the schedule of rates document. This is an important step in the modernisation of the public work system system and perhaps,

the CPWD is the first

organization to take this measure in the country. It is likely that in future, an integrated  package of an easily updatable all India schedule of rates can be developed and it will serve as an important national document useful for all the construction agencies in the country.

29

 

CHAPTER-6 ANALYSIS 

PLANS & DRAWINGS

30

 

31

 

32

 

33

 

34

 

QUANTITY ESTIMATION  6.2.1. Foundations a)Footing1:

Details of the Foundation 1: Footing Size: 5'6"X 5' X 12" Total Number: 4  Note: As per IS1200, Any footing must have a buffer of 600mm extra on either side from the face of the footing. Table 6.2.1.1 –  6.2.1.1 – detailed detailed estimation of foundation 1

S.No.

Item Description

1

Earthwork Excavation

2

P.C.C (1:4:8) R.C.C work a)In Footing1

3

 b)In Column1 Until ground surface

Length

Breadth

Height Or Thickness

Quantity

(m) 5'6"+2(0. 6) =2.88 6'0" = 1.83

(m) 5'+2(0.6) =2.72

(m) 5'0" =1.52

(m³) 11.91

5'6" = 1.68

6" = 0.15

0.46

5'6" = 1.68

5' = 1.52

12" = 0.3

0.77

21" = 0.53

9" = 0.23

3'6" = 1.07

0.13

Total R.C.C.

0.90

Earth work refilling= Earth work excavation-(R.C.C+P.C.C) =11.91-0.90-0.46 =10.55m³ 

35

Remarks

H= 5'-6"-12" = 3'6"

 

In Footing1: Table 6.2.1.2 –  6.2.1.2 –  final  final quantities of foundation 1

Item Earthwork Excavation P.C.C (1:4:8) R.C.C Work -In Footing -In Column (Until G.S) Total R.C.C Earthwork Refilling Steel b) Footing2: 

For 1 unit   11.91 m

Total No. 4

Total Quantity   47.64 m

 

4

1.84 m

0.77 m 3 0.13 m  

3

4 4

3.08 m 3 0.52 m  

 

4 4 4

3.6m 42.2 42.2 m 124.40 Kg.

0.46 m

0.90 m   10.55 m 31.10Kg

 

3

 

Details of the Footing2: Footing Size: 6'X 5'6"X 12" Total Number: 8  Note: As per IS1200, Any footing must have a buffer of 600mm extra on either side from the face of the footing. Table 6.2.1.3 –  6.2.1.3 –  detailed  detailed estimation of foundation 2

S.No.

1 2 3

Item Description

Earthwork Excavation P.C.C (1:4:8) R.C.C Work a) In Footing 1  b) In Column1 Until ground

Length

Breadth

(m) 6'+2(0.6) =3.03 6'6" =1.98

Height Or Thickness (m) (m) 5'6"+2(0.6) 5'0" =2.88 =1.52 6' 6" =1.83 =0.15

6' =1.83

5'6" =1.68

12" =0.3

Quantity

(m³) 13.26 0.54

0.92 H=5'-6"12"=3'6" 0.15

24" =0.61

9" =0.23

3'6" =1.07

surface

Total R.C.C. 36

Remarks

1.07

 

Earth work refilling= Earth work excavation-(R.C.C+P.C.C) =13.26-1.07-0.54 =11.65m³ In Foundation 2: Table 6.2.1.4 –  6.2.1.4 –  final  final quantities of foundation 2

Item Earthwork Excavation P.C.C (1:4:8) R.C.C Work -In Footing -In Column (Until G.S) Total R.C.C Earthwork Refilling Steel

For 1 unit   13.26 m

Total No. 8

Total Quantity   106.08 m

 

8

4.32 m

0.92m 3 0.15 m  

8 8

7.36 m 3 1.2 m  

1.07 m     11.65 m 38.22Kg.

8 8 8

8.56 m   93.2 93.2 m 305.76Kg.

0.54 m 3

Reinforcement for footing :

3

 

footing dimensions 5'6'' X 5'

  As per standards end cover for

•

footing = 2’’  2’’ 

  Length of steel along longer

•

span= length of footing -2 x end cover + 2 x hooks

  L1= 5’6’’5’6’’-2x2’’+2x9x0.012 2x2’’+2x9x0.012  

•

= 1.79m 

Figure 7: Footing Plan

 N0.0f bars = {(length of footing –  footing –  end  end cover) /centre to centre distance }+1 = (5’6’’(5’6’’-2x2’’)/6’’ +1 = 11.33 = 12  12  37

 

 

Total length of bar = no. of bars x length of one steel bar =21.48 m Unit weight of steel = 7850 kg/m³ Diameter of the bar = 12mm Total weight of steel = unit weight of steel x area of the bar x length of the bar = 7850 x (∏/4 x 0.012²) x 21.48  21.48  =19.07 kg Cost of steel = Rs 40/kg Total cost of steel in footings = 40 x 19.07 = Rs 768.80 Similar calculations are made for footings in shorter span direction. Table 6.2.1.5 –  6.2.1.5 –  barbending  barbending schedule of footings

S.NO

Description Shape of item

Diameter  No ( mm)

Length ( m)

Total length (m)

Unit weight

Total weight (kg)

(kg/m) 1

2

Column C1-4 nos a) longer direction  b) shorter direction Column C2-8 nos a)longer direction  b)shorter Direction

12

40

1.8

72

0.89

64.08

12

44

1.54

67.76

0.89

60.30

12

88

1.94

170.72

0.89

151.94

12

96

1.8

172.8

0.89

153.79

Total

430.16

Total quantities in foundation: Total earthwork excavation

= 47.64+106.08

38

 

= 153.72 m

3

Total quantity of p.c.c (1:4:8) =1.84+4.32 3

= 6.16 m

Total Quantity Of R.C.C. = 3.6+8.56 = 12.16 m3  Total Earthwork Refilling = 42.2+93.2 3

= 135.4 m   Total Steel Quantity In Footings = 430.16kgs  (Excluding Column part)

39

 

6.2.2 Plinth Beams R.C.C Work

S.No.

1

Description of item

Beam 1

Beam 2 2

 No.

Length

Width

2

(m) 55'6''

(m) 9''

6

Depth Or Height (m) 12''

Quantity

Total quantity

(m³)

(m³)

=16.92

=0.23

=0.3

2.33

26'6'' =8.08

9'' =0.23

12'' =0.3

3.35

21'' =0.53

9'' =0.23

12'' =0.3

-0.15

24'' =0.61

9'' =0.23

12'' =0.3

Deductions at junctions of beam1&2 At column1

At column 2

3

( Table -6.2.2.1)  

Filling inside  plinth beams 40mm HBG Metal & earth filling

4

8

1

15.54

Reinforcement in Plinth Beams 

S.NO. Description of item 1 Beam 1 Main bar

Shape

7.62

0.8

- 0.34 Total

5.19

94.73 Total

94.73

(Table –  (Table  –  6.2.2.2)  6.2.2.2) 

Diameter N0.

Length

16

8

17.16

Extra bar

16

4

Beam 2 Main bar

16

Extra bar Stirrups

Unit weight

Total quantity

137.28

1.58

216.9

10.71

42.84

1.58

67.68

24

8.32

199.68

1.58

315.5

16

12

7.51

90.12

1.58

142.39

8

456

1.11

506.16

0.39 Total

197.4 939.87

40

Total length

 

6.2.3 Compound Wall

S.NO.

1

2

Table –  Table –  6.2.3.1  6.2.3.1

Description  NO. of item

Length

Breadth

(m)

(m)

Height Quantity Or depth (m) (m³)

Earth work excavation Long wall

2

21.34

0.8

0.5

17.07

Short wall

2

10.6

0.8

0.5

8.48 Total

4

6

25.55

R.R masonry Long wall

2

20.94

0.4

0.5

8.38

Short wall

2

11

0.4

0.5

4.4 Total

3

Total quantity (m³)

12.78

Earth work refilling Long wall

2

21.34

0.4

0.5

8.54

Short wall

2

10.6

0.4

0.5

4.24 Total

12.78

Brick work Long wall

2

20.77

0.23

1.5

14.33

Short wall Deduction of gate

2

10.83

0.23

1.5

7.47

1

4

0.23

1.5

-1.38 Total

20.42

Plastering (C.M 1:4) External

1

64.34

1.5

96.51

Internal

1

62.96

1.5

94.44 Total

41

190.95 m²

 

6.2.4 Columns: a)In columns above ground surface :

Total Height of Column = (No. of Floors * Floor Height) - (No. of beams on column *beam Thickness) = (4*3m) - (3*18'') = 10.63m From N.G.L. to Plinth top, Height = 12'' Therefore Total Height of Column above G.S or G.L = 10.63+ 12'' =10.93 m (G.S = Ground Surface) Table 6.2.4.1 –  6.2.4.1 –  C.C.  C.C. work in columns

Column  No. C1 C2 

Specification Length

9” X 21”  21”  9” X 24”  24” 

Breadth

Height

(m) (m) (m) 9’=0.23m   21”=0.53m 9’=0.23m 21”=0.53m   10.93m 9’=0.23m   24”=0.61m 9’=0.23m 24”=0.61m   10.93m

Quantity (m3) 1.33 1.53

3 

Therefore, Total Column Concrete Quantity above G.S = 17.56 m

42

Total  No. 4 8 Total

Total Quantity (m3) 5.32 12.24 17.56

 

b) Reinforcement for columns :

S.No.

Description Of item

Shape

( Table -6.2.4.2 )

Diameter

 Nos.

(mm) 1

Length (m)

Total Length (m)

Unit Weight (kg/m)

Total Weight (kg)

Main bars upto plinth level for a)Column C1-4 nos  b)Column C2-8 nos

3

4

24

2.28

54.72

2.46

134.61

16

16

2.13

34.08

1.58

53.84

25

32

2.36

75.52

3.85

290.75

20

48

2.28

109.44

2.47

270.31

8

40

2.288

91.52

0.39

35.7

8

80

2.3

184

0.39

71.76

20

24

14.01

336.24

2.47

830.51

16 25

16 32

14.01 14.01

224.16 448.32

1.58 3.85

354.17 1726

20

48

14.01

672.48

2.47

1661

12

352

2.432

856

0.89

761.84

12

352

2.432

856

0.89

761.84

Stirrups upto plinth level for a)column c1-4 nos  b)column c2-8 nos Main bars from plinth level to G+3 for a)Column C1-4 nos  b)Column C2-8 nos

5

20

Stirrups from plinth level to G+3 for column C1-4 nos column C2-8 nos

43

 

6.2.5 Beams Table –  Table  –  6.2.5.1   6.2.5.1 C.C. work in roof beams

S.NO. Description of item 1 Beam 1

Beam 2

 NO. 3

6

Small beam1 (b/w 5&6)

Small beam1 (b/w 1&2)

1

1

Length

Breadth

Height

Quantity Total quantity

51'

9''

12''

=15.55

=0.23

=0.30

3.21

34' =10.36

9'' =0.23

12'' =0.30

4.29

10'3'' =3.12

9'' =0.23

12'' =0.30

0.22

11'6'' =3.51

9'' =0.23

12'' =0.3

0.24 Total

C.C work in roof beams for single floor = 7.96 m³ for total building = no. of floors X C.C work in single floor = 4 X 7.96 = 31.84 m³

44

7.96

 

d) Beam Reinforcement Calculation:

Figure 8: Beam Reinforcement Beam dimension = 13’9’’ x 9’’ x 12’’ Length of main bar in beam = total length of beam  –  2*  2* end cover + 2* hooks = 13’9’’ –  2*1’’ 2*1’’+ + 2* 9* 0.016 =4.43 m We have 4 bars of this type in one beam so , Total length of main bar = 4* 4.43 =17.72 m Extra bars at ends, length of extra bar =               –          = 2*( 13’/4 + 9’’ -1’’ + 2*9* 0.016) = 2.96 m We have 2 extra bars for this beam so, Total length of extra bars in this beam

= 2* 2.96 = 5.92 m

Total length 16 mm dia bars in this beam

= length of main bar +length of extra bars = 17.72+5.92 = 23.64 m

45

 

Unit weight of steel = 7850 kg/m³ Area of bar = ∏/4 * 0.016²  0.016²  Total weight of bars = unit weight * area* a rea* total length = 7850 * ∏/4 * 0.016² * 23.64  23.64   = 37.31kg

Dimension of stirrup = 20.5’’ X 7’’  7’’   Total Length of one stirrup = 2*( L+B + hooks ) = 2*(20.5’’+7’’-9*0.008) 2*(20.5’’+7’’-9*0.008) =1.25m  No. of stirrups = ( length of beam –  beam –  2*end  2*end cover)/center to center distance of stirrups + 1 = ( 13’9’’13’9’’- 2* 1’’)/ 7’’ +1  +1  = 24.28 = 25 Total length of all stirrups = no. of stirrups * length of single stirrup = 25 *1.25 =31.25 Unit weight of steel = 7850 kg/m³ Area of bar = ∏/4 * 0.008²  0.008²  Weight of stirrups = unit weight * area * total length of stirrups = 7850 * ∏/4 * 0.008²*31.25  0.008²*31.25   =12.33 kg

46

 

Beam Reinforcement Details Table 6.2.5.2 –  6.2.5.2 –  bar  bar bending schedule of roof beams

S.No .

Description of item

Shape

Diameter

 No

(mm) 1

Length (m)

Total length (m)

Unit weight (kg/m)

Total weight (kg)

BEAM 1 Main bars

16

12

17.92

215.04

1.58

339.76

Extra bars

16

6

10.71

64.26

1.58

101.53

16

4

3.82

15.28

1.58

24.14

16

2

2.55

5.1

1.58

8.06

Main bar

16

4

3.97

15.88

1.58

25.09

Extra bar

16

2

2.74

5.48

1.58

8.66

Beam1

8

288

1.2236

355.97

0.39

138.83

Small beam1  b/w 6&5

8

21

1.236

25.96

0.39

10.12

Small beam1  b/w 1&2 BEAM 2

8

23

1.236

28.43

0.39

11.09

Main bar

20

24

10.6

254.4

2.47

628.37

Extra bar

20

12

10.16

121.92

2.47

301.14

SMALL BEAM 1 (b/w 6&5) Main bar Extra bar SMALL BEAM 1 (b/w 1&2)

STIRRUPS

2

STIRRUPS 47

 

8mm@6''c/c

8mm@7''c/c

8

264

1.54

406.56

0.39

158.56

8

264

0.32

84.48

0.39

32.95

8

138

1.54

212.52

0.39

82.88

8

138

0.32

44.16

0.39

17.22

Total

1888.4

Total steel required in all beams in single floor = 1888.4 1 888.4 kg total steel required for beams in building = no. of floors X steel required in each floor = 4 X 1888.4 =7553.6 kg

48

 

6.2.6 Slabs In Ground Floor: slab dimensions : Length= 55'6'' Breadth=34' slab area = total slab area - openings of lift lift -opening of stair case 2

total Slab Area =55'6'' X 34' = 175.29 m   Lift dimensions : L = 6' B = 4'6'' 2

Lift Area = 6' X 4'6'' = 2.51 m   Stair case dimensions L = 12'6'' B = 6' 2

Staircase area = 12'6'' X 6' = 6.97 6 .97 m   Slab area = 175.29- 2.51 - 6.97 = 165.81 Thickness of the Slab = 4.5” 4.5”   3

Slab Quantity = 165.81X 4.5” = 18.95 m   3 Therefore Ground Floor Slab Quantity = 18.95 m   For all the floors, Slab Properties are the same and henceforth same quantity 3

Total Slab Concrete Quantity = 75.8 m

49

 

Slab Reinforcement Sample Calculations:

Sample slab dimensions 20’ X 11’  11’   End cover for slabs 20mm Along long span Length of straight bar =length of slab –  slab  – (2* (2* end cover)+ 2*hooks = 20’-(2*0.02)+(2*9*0.008) 20’-(2*0.02)+(2*9*0.008)

 

=6.2 m Length of cranked bar= length of straight bar +( 0.42*d)* no. of cranks

= 6.2+( 0.42*0.008*2) = 6.21 m  No. of bars = (length of slab- 2*end cover )/spacing of bars +1 = (20’(20’- 2*0.02)/ 6’’ +1  +1   = 40.73=41 numbers Unit weight of steel = 7850 kg/m³ Area of bar = ∏/4 *0.008²  *0.008²  Total weight of steel steel = unit weight *area*length =7850* ∏/4 *0.008² *254.4= 100.4kg *254.4= 100.4kg

50

 

i) Slabs Reinforcement Details table 6.2.6.1 –  6.2.6.1 –  bar  bar bending schedule of slabs

S.No

1

Description of item

Shape

Diameter  No.

Length

(mm)

(m)

Total length (m)

Unit weight (kg/m)

Total Weight (kg)

Along shorter span 1)b/w 1&2 a) straight  bar  b) crancked  bar

16

13

10.46

135.98

1.58

214.85

16

13

10.48

136.24

1.58

215.26

16

13

10.46

135.98

1.58

214.84

16

12

10.47

125.64

1.58

198.51

16

7

5.05

35.35

1.58

55.85

16

6

5.06

30.36

1.58

47.97

16

14

10.46

146.44

1.58

231.38

16

14

10.47

146.58

1.58

231.6

16

12

10.46

125.52

1.58

198.32

16

12

10.448

125.76

1.58

198.7

2) b/w 2&3 a) straight  bar  b) crancked  bar 3) b/w 3&4 a) straight  bar  b) crancked  bar 4) b/w 4&5 a) straight  bar  b) crancked  bar 5) b/w 5&6 a) straight  bar  b) crancked  bar

51

 

Along longer span 1) b/w staircase & lift a) straight  bar  b) crancked  bar 2) side of lift a) straight  bar  b) crancked  bar 3) side of staircase a) straight  bar  b) crancked  bar

8

17

17.4

295.8

0.39

115.36

8

17

17.44

296.48

0.39

115.63

8

12

7.65

91.8

0.39

35.8

8

12

7.67

92.04

0.39

35.9

8

26

7.65

198.9

0.39

77.57

8

26

7.67

199.42

0.39

77.77

Total

Total weight of steel in slab for one floor

2265.11

= 2265.11 kg

Total weight of steel required for building in slabs = number nu mber of slabs X total weight of steel in single slab = 4 X 2265.11 = 9060.44 kg

52

 

6.2.7 BRICK WORK Table 6.2.7 - Brick work

S.no.

1

2

Description of item

 Nos.

Length

Breadth

Height Or depth

Quantity

Total quantity

(m)

(m)

(m)

(m³)

(m³)

2

55'6'' =16.92

9'' =0.23

2.7

21

4

32'6'' =9.91

9'' =0.23

2.6

23.7

12'10'' =3.91

4" =0.1

2.7

2.1

11' =3.35

4'' =0.1

2.6

1.74

12'10'' =3.91

4'' =0.1

2.6

2.03

External walls (9") a) long wall (along beam B1)  b)short wall (along beam B2) Internal walls (4'') a)main bed room 1)long wall

2

2)short wall

2

 b)kitchen 1)long wall

2

2) short wall

4

7'10.5'' =2.4

4'' =0.1

2.7

2.6

c)Toilet wall

4

4'

4''

2.7

1.32

=1.22

=0.1

10' =3.05

4'' =0.1

3

1.83

12'7'' =3.81

4'' =0.1

2.7

1.03

10' =3.05

4'' =0.1

2.6

0.8

d) Balcony wall

2

e) C.Bed Room 1)long wall

1

2) short wall

1

53

 

f) C.Bed Room 1) long wall

1

11'4'' =3.45

4'' =0.1

2.7

0.93

2)short wall

1

10' =3.05

4'' =0.1

2.6

0.8

Total

3

DEDUCTIONS DOORS a) main door

 b) door (D)

C) door (D1)

4

WINDOWS a) window (W)

 b)window (W1)

c)window(W2)

d) kitchen window (K/W) 5

6

VENTILATOR (V) COLUMNS a) column (C1)

 b) column (C2)

2

4

8

2

9

1

2 2

4

8

3'6'' =1

9" =0.23

6'9'' =2

-0.92

3' =0.91

4'' =0.1

6'9'' =2

-0.73

2'6'' =0.76

4'' =0.1

6'9'' =2

-1.22

6' =1.8

9'' =0.23

4' =1.2

-1

4' =1.2

4'' =0.1

4' =1.2

-1.3

3' =0.9

4'' =0.1

4' =1.2

-0.11

2' =0.6 2' =0.6

4'' =0.1 4'' =0.1

1'6'' =0.45 1'6'' =0.45

21'' =0.53

9'' =0.23

2.6

-1.27

29'' =0.74

9'' =0.23

2.6

-3.5

54

-0.05 -0.05

59.88 = 60 

 

7

BALCONY a)Wide balcony

 b)kitchen  balcony

c) staircase landing

2

2

1

10' =3.05

9'' =0.23

1.68

-3

7'9'' =2.36

9'' =0.23

1.83

-2

6' =1.83

9'' =0.23

1.83

-0.77 Total deduction

Total quantity of brick for one floor

-15.92 =(-)16

= total brick work + deductions = 60-16 = 44 m³

total quantity of brick work in building

= no.of floors X single floor brick work = 3 X 44 =132 m³

total no.of bricks =  brick size

 

 

      

= 0.19 X 0.09 X 0.09 m

 brick size along with cement mortor = 0.2 X 0.1 X 0.1 m total no. of bricks

= 



 

   

= 66000

55

 

6.2.8 PLASTERING Table 6.2.8.1 –  6.2.8.1 –  plastering  plastering work

S.no.

Decsription of item

 Nos.

18mm cement  plastering 1:4 in walls 1

Main bed room a) long wall

 b) short wall

c) slab

d) column 2

Kitchen room a)long wall

 b)short wall

c)slab 3

Toilets (6' X 4') a) long wall

 b)short wall

c) slab

4

4

2

4

4

4

2

4

4

2

Length

Breadth

Height or depth

Quantity

Total quantity

(m)

(m)

(m)

(m²)

(m²)

12'6'' =3.81

10' =3.05

46.48

11' =3.35

10' =3.05

40.87

12'6'' =3.81

11' =3.35

25.53

4'5'' =1.35

8'6'' =2.59

14

9' =2.74

10' =3.05

33.43

7'10.5'' =2.4

10' =3.05

29.28

9' =2.74

7'10.5'' =2.4

13.15

6' =1.83

10' =3.05

22.33

4' =1.22

10' =3.05

14.88

6' =1.83

4' =1.22

56

4.47

 

4

5

Toilets (6'2'' X 4') a)long wall

4

6'2'' =1.88

10' =3.05

22.94

 b) short wall

4

4' =1.22

10' =3.05

14.88

c) slab

2

6'2'' =1.88

Dining hall (10' X 8'4.5'') a) long wall

 b)short wall

6

c)slab Dining hall (10' X 9'7.5'') a) long wall

 b)short wall

c)slab 7

4' =1.22

4.59

1

10' =3.05

10' =3.05

9.3

2

8'4.5'' =2.55

10' =3.05

15.56

1

10' =3.05

1

2

1

8'4.5'' =2.55

7.78

10' =3.05

10' =3.05

9.3

9'7.5'' =2.93

10' =3.05

17.87

10' =3.05

9'7.5'' =2.93

8.94

Living hall (20'4.5'' X 12'3'') a) long wall

1

20'4.5'' =6.21

10' =3.05

18.94

 b)short wall

2

12'3'' =3.73

10' =3.05

22.75

c) slab

Living hall (20'4.5'' X 11') a)long wall

1

1

20'4.5'' =6.21

12'3'' =3.73

20'4.5'' =6.21

23.16

10' =3.05

57

18.94

 

 b) short wall

c) slab 8

C.BED ROOM (11' X 10') a) short wall  b) short wall

c) slab

d)columns

C.BED ROOM (12'3'' X 10') a)long wall

 b) short wall

c)slab

d) column

9

Lift a) long wall

 b) short wall 10

Wide corridor a) long wall

 b) short wall

2

1

2 2

1

4

2

2

1

4

2

2

2

1

11' =3.35

10' =3.05

20'4.5'' =6.21

11' =3.35

20.8

10' =3.05 10' =3.05

11' =3.35 10' =3.05 11' =3.35

10' =3.05

20.44

20.44 18.61

10.22

4.5'' =0.11

8'6'' =3

1.32

12'3'' =3.73

10' =3.05

22.75

10' =3.05

10' =3.05

18.61

12'3'' =3.73

10' =3.05

11.38

4.5'' =0.11

8'6'' =3

1.32

6' =1.83

10'4.5'' =3.16

11.57

4'6'' =1.37

10'4.5'' =3.16

8.66

16'6.5'' =5.04

10' =3.05

30.74

6' =1.83

10' =3.05

5.58

58

 

c) slab 11

WIDE BALOCNY a) long wall

1

2

4  b) short wall 2 c) slab 2 d) short long wall 2

12

e) short long wall top Kitchen wash a) long wall

 b) short wall

c) slab

13

2

4

2

16'6.5'' =5.04

10' =3.05

15.37

10' =3.05

10' =3.05

18.61

3' =0.91

10' =3.05

11.10

3' =0.91

10' =3.05

5.55 3' =0.91

10' =3.05 9'' =0.23

10' =3.05

5.55

1.4

8'1'' =2.46

10' =3.05

15

3'6'' =1.07

10' =3.05

13.05

3'6'' =1.07

8'1'' =2.46

5.26 3' =0.91

8'1'' =2.46

d) short long wall

2

e) short long wall top Out side a) long wall

2

8'1'' =2.46

2

55'6'' =16.92

10'4.5'' =3.16

106.93

34' =10.36

10'4.5'' =3.16 Total

65.48 910.72

 b) short wall

2

9'' =0.23

59

4.48

1.13

 

Deductions DOORS 1) M.D

2)D

3)D1

WINDOWS 1) W

2)W1

3)W2

4) K/W

5) V

4

8

16

4

18

2

4

4

3'6'' =1.07

6'9'' =2.06

-8.82

3' =0.91

6'9'' =2.06

-15

2'6'' =0.76

6'9'' =2.06

-25.05

6' =1.83

4' =1.22

-8.93

4' =1.22

4' =1.22

-26.8

4' =1.22

3' =0.91

-2.22

3' =0.91

2'6'' =0.76

-2.77

2' =0.61

1'6'' =0.46

-1.12

OUT SIDE OPENINGS a) wide  balcony

2

2  b) kitchen wash

10' =3.05

7' =2.13

-13

7'10.5'' =2.4

7' =2.13

-10.22

Total deducti on

-113.91

  Painting is similar to plastering .



60

 

6.2.9 Stair case Table 6.2.9.1 –  6.2.9.1 –  C.C.  C.C. work in stair case S.NO

Description of  No item

Length Breadth (m)

1

Stair case R.c.c bed

3.09

(m) 3' 0.91

6' 1.83

3'6'' 1.07

2

1 Landing area

Height Quantity Total quantity (m) (m³) (m³) 5'' 0.71 0.127 5'' 0.127

Remarks

0.25 Total

0.96

Reinforcement in staircase Table 6.2.9.2 –  6.2.9.2 –  bar  bar bending schedule of stair case

S.NO.

1

Description of item Main reinforcement Distribution reinforcement

shape

diameter NO.

Length

Total length

Unit weight

Total quantity

12

14

3.68

51.52

0.89

45.85

8

32

0.86

27.53

0.39 Total

10.73 56.58

reinforcement in staircase for single floor = 56.58 kg reinforcement in total staircase = no. of floors X reinforcement in single floor = 4 X 56.58 = 226.32 kg

61

 

6.2.10 LINTELS Table 6.2.10.1 –  6.2.10.1 –  C.C.  C.C. work in lintels S. NO

1

Description  NO. of item

Over M.D D D1 W W1 W2 K/W V

2 4 8 2 9 1 2 2

Length

Breadth

Height Or depth

Quantity

Total quantity

(m)

(m)

(m)

(m³)

(m³)

0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1

0.23 0.1 0.1 0.23 0.23 0.1 0.1 0.23

1.37 1.22 1.07 2.13 1.52 1.22 1.22 1.07

0.06 0.05 0.09 0.1 0.31 0.01 0.02 0.05 TOTAL

0.69

For three floors = 3 X 0.69 = 2.07 m³

6.2.11 SKIRTING Table 6.2.11.1 - skirting

S.NO.

1

Description  NO. of item M.BED C.BED Living, dining hall Kitchen Wide  balcony K/wash Toilets

Length

Breadth

Height

Quantity

(m)

(m)

2 2

(RM) 14.32 13.56

(RM) 28.64 27.12

2 2

25.11 10.29

50.22 20.58

2 2 4

7.92 7.06 6.1

15.84 14.12 24.4 Total

62

Total quantity (RM)

180.92

 

6.2.12 AREA UNDER TILES

S.NO. Description of  N0. item

( table 6.2.12.1)

Length

Breadth

(m)

(m)

Depth Or height (m)

Quantity (m²)

Total quantity (m²)

1 Common bed

1

room (12'3'' X 10')

12'3''

10'

=3.73

=3.05

11.38

Dining hall (10' X 9'7.5'')

1

10' =3.05

9'7.5'' =2.93

8.94

Living hall (20'4.5'' X 11')

1

20'4.5'' =6.21

11' =3.35

20.8

2

10' =3.05

3' =0.91

5.55

2

9' =2.74

7'10.5'' =2.4

13.15

2

7'10.5'' =2.4

3'6'' =1.07

5.13

2

6' =1.83

4' =1.22

4.47

2

6'2'' =1.88

4' =1.22

4.47

1

20'4.5''

12'3''

23.16

=6.21

=3.73

Wide balcony

Kitchen

Kitchen wash area Toilets (6' X 4') Toilets (6'2'' X 4') Living (20'4.5''hall X 12'3'')

1

10' =3.05

8'4.5'' =2.55

7.78

Dining hall (10' X 8'4.5'')

1

11' =3.35

10' =3.05

10.22

Common bed room (11' X 10')

1

16'6.5'' =5.04

6' =1.83

9.22

Wide corridor (16'6.5'' X 6') Total

63

124.27

 

64

 

65

 

66

 

67

 

68

 

RESULTS Table 7.1.1 S.No 1 2 3 4

5 6

Description of item Earth work excavation

Quantity 179.27 m³

P.C.C bed concrete Total R.C.C work quantity Total Cement mortar a) for bricks  b) plastering c) under tiles Total bricks Steel   8mm dia bars   12mm dia bars   16mm dia bars   20mm dia bars   25mm dia bars Total Steel Total cement bags ( 50kg / bag) Fine aggregates (sand ) in tones Coarse aggregates in tones

6.16 m³ 148.48 m³











7 8 9

36.02 m³ 15.96 m³ 7.88 m³ 78130 3986.5kg 2137.24kg 10408.56 kg 6614.47 kg 2106.75 kg 25,251kgs 1045 bags 150 tonnes 122 tonnes

1m³ 20mm aggregate

= 1.43 metric tonnes

1m³ of cement

= 1440 kg

1m³ of sand

= 1602 kg

Land cost per sq. yard

= 42, 000

Total area

= (40' X 70') = 311.11 sq. yards

Total cost of land

= Rs 1,30,66,667/- 

Total construction cost

= Rs 65,92,902/- 

Total cost

= cost of land + cost of construction = 1,30,66,667 + 65,92,902 

= Rs 1,96,59,569/69

 

CONCLUSION

The estimate also gives an idea of the time required for the completion of the work, i.e. the probable time of completion can also be calculated. Also before the start of any work, at least probable cost has to be found out, here estimation and costing plays an important role. The estimate is also required for inviting tenders and to arrange contract and to control the expenditure during execution.

The primary object of an estimate is to enable one to know, beforehand, the cost of work. The actual cost is known only after the completion of the work from the account of completed work. The estimate may be prepared approximately as a preliminary estimate by various methods without going into the details of different items of work, to know the approximate cost or rough cost.

Estimation and Analysis of Rates of various Items of Building are calculated and  presented in this documentation. All the calculations are based on the Design Drawings  provided, Standard Schedule of Rates, Andhra Pradesh, 2013-14 and Standard Data Book. Reading the drawings, which is the essential feature of a Civil Engineer, has been learned all through this project.

70

 

REFERENCES

[1] IS: 1200 –   –  “Hand Book of Method of Measurement of Building Works”  Works” 

[2] SP-34 –   –  “Hand book on Concrete Reinforcement and Detailing”  Detailing”  

th

[3] “Estimating and Costing in Civil Engineering by B.N. Dutta”,   26   revised Edition, UBS Publishers’ Distributors pvt. Ltd. , 2007, pages 1, 4-11, 4 -11, 13-20, 213-214, 448-449, 472-517, 564. [4] Standard Schedule of Rates (SSR), Andhra Pradesh, 2013-14 [5] Standard Data Book –  Book  –  For  For Material and Labour Constants

71