House Estimation

ESTIMATEESTIMATE

An estimate of the cost of a An estimate of the cost of a construction job is the probable cost of construction job is the probable cost of that job as computed from plans and that job as computed from plans and specificationsspecifications..

For a good estimate the, actual cost of the For a good estimate the, actual cost of the proposed work after completion should not proposed work after completion should not differ by more then 5 to 10 % from its differ by more then 5 to 10 % from its approximate cost estimate, provided there approximate cost estimate, provided there are no unusual, unforeseen circumstances.are no unusual, unforeseen circumstances.

ESTIMATIONESTIMATION

Estimation is the scientific way of Estimation is the scientific way of working out the approximate cost of working out the approximate cost of an engineering project before an engineering project before execution of the workexecution of the work..

It is totally different from calculation of the It is totally different from calculation of the exact cost after completion of the project. exact cost after completion of the project.

Estimation requires a thorough Knowledge Estimation requires a thorough Knowledge of the construction procedures and cost of of the construction procedures and cost of materials & labour in addition to the skill , materials & labour in addition to the skill , experience, foresight and good judgment.experience, foresight and good judgment.

TYPES OF ESTIMATESTYPES OF ESTIMATES

There are two main types of estimates:-There are two main types of estimates:-1 = Rough cost estimate.1 = Rough cost estimate.2 = Detailed estimate.2 = Detailed estimate.

Depending upon the purpose of estimate, Depending upon the purpose of estimate, some types of detailed estimate are as some types of detailed estimate are as follows:-follows:-

a)a) Contractor's estimateContractor's estimateb)b) Engineer's estimateEngineer's estimatec)c) Progress estimateProgress estimate

I = Rough cost estimateI = Rough cost estimate

• Estimation of cost before construction from Estimation of cost before construction from plans or architectural drawings of the plans or architectural drawings of the project scheme, when even detailed or project scheme, when even detailed or structural design has not been carried out, structural design has not been carried out, is called Rough cost estimate.is called Rough cost estimate.

• These estimates are used for obtaining These estimates are used for obtaining Administrative Approval from the Administrative Approval from the concerning Authorities. concerning Authorities.

• Sometimes, on the basis of rough cost Sometimes, on the basis of rough cost estimates, a proposal may be dropped estimates, a proposal may be dropped altogether. altogether.

Rough cost estimate (-ctd-)Rough cost estimate (-ctd-)

• Unit cost Unit cost is worked out for projects is worked out for projects similar to the project under consideration similar to the project under consideration carried out recently in nearly the same site carried out recently in nearly the same site conditions. conditions.

• Unit cost means cost of execution of a unit Unit cost means cost of execution of a unit quantity of the work. quantity of the work.

Rough cost estimate (-ctd-)Rough cost estimate (-ctd-)• To find rough cost of any project, this worked To find rough cost of any project, this worked

average unit cost is multiplied with total quantity average unit cost is multiplied with total quantity of the present work in the same units. of the present work in the same units.

• For example, in case of a building, plinth area For example, in case of a building, plinth area (sq. ft.) of the proposed building is worked out, (sq. ft.) of the proposed building is worked out, which is then multiplied by the cost per unit area which is then multiplied by the cost per unit area (Rs. /ft(Rs. /ft22) of similar building actually constructed ) of similar building actually constructed in the near past in nearly the same site in the near past in nearly the same site conditions, to find out the rough cost estimate of conditions, to find out the rough cost estimate of the building. the building.

• This cost is sometimes adjusted by the average This cost is sometimes adjusted by the average percentage rise in the cost of materials and percentage rise in the cost of materials and wages. wages.

Rough cost estimateRough cost estimate The rough cost estimate may be prepared on the The rough cost estimate may be prepared on the

following basis for different types of projects:following basis for different types of projects:

1. Cost per square foot of covered area (plinth area) is 1. Cost per square foot of covered area (plinth area) is the most the most commonly adopted criterion for preparing commonly adopted criterion for preparing rough cost estimate for most of the residential rough cost estimate for most of the residential buildings.buildings.

2. For public buildings, cost. Per person (cost per 2. For public buildings, cost. Per person (cost per capita) is capita) is used. For example,used. For example,

Students hostel———————-—cost per studentStudents hostel———————-—cost per student

Hospitals————————————Cost per bedHospitals————————————Cost per bed

Hotel—————————————Cost per GuestHotel—————————————Cost per Guest

Rough cost estimate (-ctd-)Rough cost estimate (-ctd-)3.3. Cost per cubic foot Cost per cubic foot is particularly suitable for is particularly suitable for

commercial offices, shopping centers, and commercial offices, shopping centers, and factory buildingsfactory buildings, etc., etc.

4.4. For For water tank/reservoirwater tank/reservoir, cost may be worked out , cost may be worked out on the basis of capacity in on the basis of capacity in gallons of water gallons of water stored.stored.

5.5. For roads and railwaysFor roads and railways, cost may be found out , cost may be found out per mile/kilometer per mile/kilometer of length.of length.

6.6. For streetsFor streets, cost may be , cost may be per hundred feet/meters per hundred feet/meters of length.of length.

7.7. In case of In case of bridgesbridges, , cost per foot/meter cost per foot/meter of clear of clear span may be calculated.span may be calculated.

DETAILED ESTIMATEDETAILED ESTIMATE

• Detailed estimates are prepared by carefully Detailed estimates are prepared by carefully and separately calculating in detail the costs and separately calculating in detail the costs of various items of the work that constitute of various items of the work that constitute the whole project from the detailed working the whole project from the detailed working drawings after the design has been finalizeddrawings after the design has been finalized. .

• The mistakes, if any, in the rough cost estimate are The mistakes, if any, in the rough cost estimate are eliminated in the detailed estimate. eliminated in the detailed estimate.

• Detailed estimates are submitted to the competent Detailed estimates are submitted to the competent authorities for obtaining technical sanction.authorities for obtaining technical sanction.


The whole project is sub-divided into different The whole project is sub-divided into different items of work or activities. The quantity for each items of work or activities. The quantity for each item is then calculated separately from the item is then calculated separately from the drawings as accurately as possible. The procedure drawings as accurately as possible. The procedure is known as is known as ""taking out of quantitiestaking out of quantities".".

The quantities for each item may be estimated The quantities for each item may be estimated and shown in the pattern which is called and shown in the pattern which is called ""Bill of Bill of quantities."quantities."

The unit, in which each item of the wok is to be The unit, in which each item of the wok is to be calculated, should be according to the prevailing calculated, should be according to the prevailing practice as followed in various departments of the practice as followed in various departments of the country.country.


Each item of the work is then multiplied by its Each item of the work is then multiplied by its estimated current rate calculated by a fixed procedure estimated current rate calculated by a fixed procedure to find out to find out cost of the itemcost of the item. .

At the end, a total of all items of the work are made to At the end, a total of all items of the work are made to get the get the total estimated costtotal estimated cost..

The rates are usually as per The rates are usually as per Schedule of RatesSchedule of Rates for the for the locality plus a locality plus a premiumpremium to allow for rise in labor and to allow for rise in labor and material rates over and above the schedule of rates. material rates over and above the schedule of rates.

A percentage, usually 5% is also provided on the total A percentage, usually 5% is also provided on the total estimated cost for the work to allow for the possible estimated cost for the work to allow for the possible contingenciescontingencies due to unforeseen items or expenditure due to unforeseen items or expenditure or other causes, besides 2% or other causes, besides 2% establishment chargesestablishment charges..


Besides drawings and details of measurements and Besides drawings and details of measurements and calculation of quantities (Bill of Quantities), the following calculation of quantities (Bill of Quantities), the following documents documents are also usually submitted with the detailed are also usually submitted with the detailed estimate for obtaining Technical Sanction:estimate for obtaining Technical Sanction:

1.1. A A reportreport explaining History, necessity, scope and main explaining History, necessity, scope and main features of the project, its design, and estimate, etc.features of the project, its design, and estimate, etc.

2. 2. SpecificationsSpecifications lying down the nature and class of work lying down the nature and class of work and material to be used in various parts of the work.and material to be used in various parts of the work.

3. 3. The The abstract of costabstract of cost (priced Bill of Quantities) showing the (priced Bill of Quantities) showing the total quantities under each sub-head, rate per unit of total quantities under each sub-head, rate per unit of measurement, and cost.measurement, and cost.

4. 4. Calculation sheetsCalculation sheets showing calculations for important showing calculations for important parts of the structure. In fact, in estimating the art and parts of the structure. In fact, in estimating the art and skill lies only in the computation of details without any skill lies only in the computation of details without any omissions, of all parts of the building or work.omissions, of all parts of the building or work.

CLASSIFICATION DEPENDING UPON CLASSIFICATION DEPENDING UPON PURPOSE OF DETAILED ESTIMATEPURPOSE OF DETAILED ESTIMATE

1- CONTRACTOR ESTIMATE1- CONTRACTOR ESTIMATE

It is made by the contractor for determining It is made by the contractor for determining the price or prices to be bid. the price or prices to be bid.

It is usually a carefully prepared detailed It is usually a carefully prepared detailed estimateestimate..

2- ENGINEER’S ESTIMATE2- ENGINEER’S ESTIMATE

This type of estimate is made by the Engineer This type of estimate is made by the Engineer (Consultant) usually for the purposes of (Consultant) usually for the purposes of financing the work and for checking bids and financing the work and for checking bids and running bills submitted by contractors.running bills submitted by contractors.

3- PROGRESS ESTIMATES3- PROGRESS ESTIMATES

• These are made by the These are made by the EngineerEngineer at at regular intervals for the completed parts regular intervals for the completed parts of the project during the progress of the of the project during the progress of the work for determining the amounts of work for determining the amounts of partial payments to be made to the partial payments to be made to the contractor. contractor.

• On large contracts, such estimates are On large contracts, such estimates are commonly made each month and, hence, commonly made each month and, hence, are frequently called are frequently called monthly estimatesmonthly estimates..

UNFORESEEN ITEMS IN DETAILED ESTIMATE UNFORESEEN ITEMS IN DETAILED ESTIMATE

• While preparing a detailed estimate, one had to While preparing a detailed estimate, one had to be very careful to see that all items of the work be very careful to see that all items of the work are incorporated. are incorporated.

• It is likely that a few Items, though unimportant It is likely that a few Items, though unimportant in nature, might have been overlooked and in nature, might have been overlooked and which may result in raising the estimate of the which may result in raising the estimate of the project. project.

• There may be also certain unforeseen There may be also certain unforeseen circumstances affecting the project. circumstances affecting the project.

• Hence, a certain allowance usually Hence, a certain allowance usually 5 to 10% 5 to 10% of of the total cost, is made in the estimation which the total cost, is made in the estimation which will take care of all these items that are will take care of all these items that are unforeseen or are overlooked and are known as unforeseen or are overlooked and are known as "Contingencies"."Contingencies".

METHODS OF DETAILED ESTIMATEMETHODS OF DETAILED ESTIMATE The dimensions, length, breadth and height or depth The dimensions, length, breadth and height or depth

are to be taken out from the working drawings (plan, are to be taken out from the working drawings (plan, elevation and section). elevation and section).

Junctions of walls, cornersJunctions of walls, corners and the and the meeting pointsmeeting points of of walls require special attention. walls require special attention.

For symmetrical footings, which is the usual case, For symmetrical footings, which is the usual case, earthwork in excavation in foundations, foundation earthwork in excavation in foundations, foundation concrete, brickwork in foundation and plinth, and concrete, brickwork in foundation and plinth, and brickwork in superstructure may be estimated by either brickwork in superstructure may be estimated by either of the of the two methodstwo methods::

(1)(1) SEPARATE OR INDIVIDUAL WALL SEPARATE OR INDIVIDUAL WALL METHODMETHOD

(2) CENTER LINE METHOD(2) CENTER LINE METHOD

SEPARATE OR INDIVIDUAL WALLS METHODSEPARATE OR INDIVIDUAL WALLS METHOD

• The walls running in one direction are termed as The walls running in one direction are termed as ""long wallslong walls”” and the walls running in the and the walls running in the transverse direction, as transverse direction, as ""Short waLlsShort waLls",", without without keeping in mind which wall is lesser in length keeping in mind which wall is lesser in length and which wall is greater in length. and which wall is greater in length.

• Lengths of long walls are measured or found Lengths of long walls are measured or found ""Out-to outOut-to out"" and those of short walls as " and those of short walls as "In-to-In-to-in".in".

• Different Different quantitiesquantities are calculated by are calculated by multiplying the length by the breadth and the multiplying the length by the breadth and the height of the wall. height of the wall.

• The same rule applies to the excavation in The same rule applies to the excavation in foundation, to concrete bed in foundation, foundation, to concrete bed in foundation, D.P.C., masonry in foundation and super D.P.C., masonry in foundation and super structure etc.structure etc.


• For symmetrical footing on either side, the For symmetrical footing on either side, the center line remains same for super structure, center line remains same for super structure, foundation and plinth. So, the simple method is foundation and plinth. So, the simple method is to find out the centre-to-centre lengths of long to find out the centre-to-centre lengths of long walls and short walls from the plan.walls and short walls from the plan.

• Long wall length out-to-outLong wall length out-to-out = Center to center length + half breadth on one = Center to center length + half breadth on one Side + half breadth on other side.Side + half breadth on other side.

= Center to center length + one breadth= Center to center length + one breadth

• Short wall length in-to-inShort wall length in-to-in = Center to Center = Center to Center length - one breadth.length - one breadth.


This method can also be worked out in a quicker way., as follows:This method can also be worked out in a quicker way., as follows:

For long wallsFor long walls

• First of all, find the length of the First of all, find the length of the foundation trenchfoundation trench of the long of the long wall wall “out-to-out”“out-to-out” in the same manner as explained above. in the same manner as explained above.

• The length of the The length of the foundation concretefoundation concrete is the same. is the same. • For the length of the For the length of the first footingfirst footing or first step of the brick wall, or first step of the brick wall,

subtract two offsets (2x6"=12") in foundation concrete from the subtract two offsets (2x6"=12") in foundation concrete from the length of the trench or concrete. length of the trench or concrete.

• For the For the second footingsecond footing subtract from the length of the 1st footing subtract from the length of the 1st footing two offsets (2x2.25"= 4.5"), for two offsets (2x2.25"= 4.5"), for 3rd footing3rd footing subtract from the subtract from the length of the 2nd footing 2 offsets (4.5") and in this way deal length of the 2nd footing 2 offsets (4.5") and in this way deal with the long walls up to the super-structure. with the long walls up to the super-structure.

For short wallsFor short walls

Follow he same method but instead of subtracting add two offsets Follow he same method but instead of subtracting add two offsets to get the corresponding lengths to get the corresponding lengths in-to-inin-to-in. .

CENTRE LINE METHODCENTRE LINE METHOD In this method, total length of centre lines of walls, long In this method, total length of centre lines of walls, long

and short, has to be found out. and short, has to be found out. Find the total length of centre lines of walls of same Find the total length of centre lines of walls of same

type, having same type of foundations and footings and type, having same type of foundations and footings and then find the quantities by multiplying the total centre then find the quantities by multiplying the total centre length by the respective breadth and the height. length by the respective breadth and the height.

In this method, the length will remain the same for In this method, the length will remain the same for excavation in foundations, for concrete in foundations, excavation in foundations, for concrete in foundations, for all footings, and for superstructure (with slight for all footings, and for superstructure (with slight difference when there are cross walls or number of difference when there are cross walls or number of junctions). junctions).

This method is quicker but requires special attention This method is quicker but requires special attention and considerations at the junctions, meeting points of and considerations at the junctions, meeting points of partition or cross walls. partition or cross walls.

CENTRE LINE METHODCENTRE LINE METHOD For rectangular, circular polygonal (hexagonal, For rectangular, circular polygonal (hexagonal,

octagonal etc) buildings having no inter or cross octagonal etc) buildings having no inter or cross walls, this method is quite simple. walls, this method is quite simple.

For buildings having cross or partition walls, for For buildings having cross or partition walls, for every junction, half breadth of the respective every junction, half breadth of the respective item or footing is to be deducted from the total item or footing is to be deducted from the total centre length. centre length.

Thus in the case of a building with one partition Thus in the case of a building with one partition wall or cross wall having two junctions, deduct wall or cross wall having two junctions, deduct one breadth of the respective item of work from one breadth of the respective item of work from the total centre length. the total centre length.

CENTRE LINE METHODCENTRE LINE METHOD

For buildings having different types of walls, each set of For buildings having different types of walls, each set of walls shall have to be dealt separately. walls shall have to be dealt separately.

Find the total centre length of all walls of one type and Find the total centre length of all walls of one type and proceed in the same manner as described above. Similarly proceed in the same manner as described above. Similarly find the total centre length of walls of second type and find the total centre length of walls of second type and deal this separately, and so on. deal this separately, and so on.

Suppose the outer walls (main walls) are of A type and Suppose the outer walls (main walls) are of A type and inner cross walls are of B type. inner cross walls are of B type.

Then all A type walls shall be taken jointly first, and then Then all A type walls shall be taken jointly first, and then

all B type walls shall be taken together separately.all B type walls shall be taken together separately. In such cases, no deduction of any kind need be made for A In such cases, no deduction of any kind need be made for A

type walls, but when B type walls are taken, for each type walls, but when B type walls are taken, for each junction deduction of half breadth of A type walls (main junction deduction of half breadth of A type walls (main Walls) shall have to be made from the total centre length Walls) shall have to be made from the total centre length of B type walls.of B type walls.

CENTRE LINE METHODCENTRE LINE METHOD

At corners of the building where two walls At corners of the building where two walls are meeting, no subtraction or addition is are meeting, no subtraction or addition is required. required.

In the figure, the double cross-hatched In the figure, the double cross-hatched areas marked P,Q,R, & S come twice, while areas marked P,Q,R, & S come twice, while blank areas, A,B,C, & D do not come at all, blank areas, A,B,C, & D do not come at all, but these portions being equal in but these portions being equal in magnitude, we get the correct quantity.magnitude, we get the correct quantity.

DESCRIPTION AND UNITS DESCRIPTION AND UNITS OF MEASUREMENT FOR OF MEASUREMENT FOR

COMMON ITEMSCOMMON ITEMS

1 = SITE CLEARANCE WORKS1 = SITE CLEARANCE WORKS

• This item is described in detail but This item is described in detail but the price of this item is usually the price of this item is usually indicated as indicated as lump sum (LS).lump sum (LS).

• The cost of this item is provided in The cost of this item is provided in the estimate by judgment, the estimate by judgment, according to the description of the according to the description of the item and is indicated as item and is indicated as Lump sum Lump sum (L.S). (L.S).

2 = EXCAVATION FOR FOUNDATION TRENCHES2 = EXCAVATION FOR FOUNDATION TRENCHES

• Earthwork in excavation for foundation Earthwork in excavation for foundation trenches is calculated by taking the trenches is calculated by taking the dimensions of each trench as dimensions of each trench as length X length X breadth X depth.breadth X depth.

• It is measured in cubic ft, cubic yard or It is measured in cubic ft, cubic yard or cubic meter, according to the prevailing cubic meter, according to the prevailing practice.practice.

• The payment for this item is generally The payment for this item is generally

done as Rs. per hundred cubic ft. done as Rs. per hundred cubic ft.

FILLING IN TRENCHESFILLING IN TRENCHES

Filling in trenchesFilling in trenches after the after the construction of foundation construction of foundation masonry is ordinary neglected. If masonry is ordinary neglected. If the trench filling is, also taken in the trench filling is, also taken in account, it may be calculated by account, it may be calculated by deducing the volume of masonry deducing the volume of masonry in trenches from that of the in trenches from that of the volume of excavation.volume of excavation.

3 = FOUNDATION CONCRETE (P.C.C.)3 = FOUNDATION CONCRETE (P.C.C.)

• The type of concrete must be clearly The type of concrete must be clearly mentioned. The mix proportions and the type of mentioned. The mix proportions and the type of cement, sand and coarse aggregate must be cement, sand and coarse aggregate must be specified. specified.

• This item is measured in cubic ft and the This item is measured in cubic ft and the unit for measurement is, generally Rs. per unit for measurement is, generally Rs. per 100 cubic ft.100 cubic ft.

• When the soil is soft or weak, one layer of When the soil is soft or weak, one layer of dry dry bricks or stone solingbricks or stone soling is applied below the is applied below the foundation concrete. The soling layer is foundation concrete. The soling layer is computed in computed in sq.ft (length X breadth),sq.ft (length X breadth), specifying specifying the thickness in description of item.the thickness in description of item.

4 = BRICKWORK IN FOUNDATION UP TO PLINTH4 = BRICKWORK IN FOUNDATION UP TO PLINTH

Care must be taken, while taking dimensions Care must be taken, while taking dimensions from the drawings in the bill of quantities from the drawings in the bill of quantities because the walls in this part of the structure because the walls in this part of the structure are in the form of steps with changing are in the form of steps with changing dimensions. dimensions.

This item is calculated in cft and the unit for This item is calculated in cft and the unit for payment is Rs. per 100 cft.payment is Rs. per 100 cft.

In the description of work, the quality of bricks In the description of work, the quality of bricks and mortar ratio must be specified. For and mortar ratio must be specified. For example,example,"Brickwork in foundation and plinth using first "Brickwork in foundation and plinth using first class bricks laid in (1:4) or (1:6) cement-sand class bricks laid in (1:4) or (1:6) cement-sand (c/s) mortar———————“(c/s) mortar———————“

5 = BRICKWORK IN SUPER STRUCTURE5 = BRICKWORK IN SUPER STRUCTURE

Important considerations are:Important considerations are:

a =a = Measurements of walls shall be taken in the Measurements of walls shall be taken in the same order and in the same manner as for same order and in the same manner as for brickwork in foundations and plinth.brickwork in foundations and plinth.

b =b = In the first measurements, all openings such In the first measurements, all openings such as doors, windows, veranda openings etc. shall as doors, windows, veranda openings etc. shall be neglected. However, deductions shall be be neglected. However, deductions shall be made for all openings in the walls, at the end of made for all openings in the walls, at the end of the item.the item.

BRICKWORK IN SUPER STRUCTURE (ctd)BRICKWORK IN SUPER STRUCTURE (ctd)

c = In the description of the work, the c = In the description of the work, the quality quality of bricks and mortar ratioof bricks and mortar ratio have to be specified. have to be specified.

d = d = Masonry for archesMasonry for arches shall be paid separately, shall be paid separately, at a different rate.at a different rate.

e = The height of super structure is very e = The height of super structure is very important. Generally the quantities are important. Generally the quantities are worked out for each storey separately and worked out for each storey separately and rates would be different for different storeis rates would be different for different storeis because of additional labor work, scaffolding because of additional labor work, scaffolding and shuttering.and shuttering.

f = f = The item is worked out in cft and the The item is worked out in cft and the standard unit for payment is Rs. Per 100 cft.standard unit for payment is Rs. Per 100 cft.

6 = DAMP PROOF COURSE (D.P.C.)6 = DAMP PROOF COURSE (D.P.C.)

Horizontal D.P.C.Horizontal D.P.C. shall extend the full width of shall extend the full width of the super structure walls, however, it shall not the super structure walls, however, it shall not be provided across doorways and veranda be provided across doorways and veranda openings. It is also provided in roof and floors.openings. It is also provided in roof and floors.

Vertical D.P.C.Vertical D.P.C. is provided in external walls, is provided in external walls,

especially, in the walls of basements.especially, in the walls of basements.

The quantity of D.P.C. is estimated in square ft.The quantity of D.P.C. is estimated in square ft.(on area basis) and standard unit for payment (on area basis) and standard unit for payment is Rs. per 100 sft.is Rs. per 100 sft.

7 = ROOFING & RCC WORKS7 = ROOFING & RCC WORKS Area of the Area of the Roof slabRoof slab is calculated by taking inside is calculated by taking inside

dimensions of the room plus a bearing of the roof slab dimensions of the room plus a bearing of the roof slab on the walls, on all sides. on the walls, on all sides.

For R.C.C. Roof slabs and beamsFor R.C.C. Roof slabs and beams, the total quantities of , the total quantities of concrete and steel are estimated, separately. concrete and steel are estimated, separately.

The quantity of plain concrete is estimated in cft and The quantity of plain concrete is estimated in cft and the standard unit for payment of concrete is Rs. per the standard unit for payment of concrete is Rs. per 100 cft.100 cft.

Volume of Volume of Reinforcing SteelReinforcing Steel is not deducted , while is not deducted , while

estimating the volume of plain concrete for payment.estimating the volume of plain concrete for payment.

c = c = R.C.C. lintelsR.C.C. lintels over wall openings such as doors over wall openings such as doors and windows are also included in R.C.C. work.and windows are also included in R.C.C. work.

ROOFING & RCC WORKS (ctd)ROOFING & RCC WORKS (ctd)• Roof consisting of beams, battens, and tiles or wooden Roof consisting of beams, battens, and tiles or wooden

planks is estimated for each part, separately. planks is estimated for each part, separately.

Steel beam is estimated by weight, whereas, wooden Steel beam is estimated by weight, whereas, wooden beam is measured in cft. Battens are estimated by beam is measured in cft. Battens are estimated by numbers indicating there size and lengths. Tiles are numbers indicating there size and lengths. Tiles are also estimated by size and numbers.also estimated by size and numbers.

• Roof finishingRoof finishing may consist of bitumen coating and/or may consist of bitumen coating and/or Polythene sheets (water proofing) , earth filling (heat Polythene sheets (water proofing) , earth filling (heat proofing) and brick tiles, etc. proofing) and brick tiles, etc.

Dimensions are taken from inner face to inner face of Dimensions are taken from inner face to inner face of parapet walls. parapet walls.

This item is estimated in sft and a composite rate for This item is estimated in sft and a composite rate for payment is taken as Rs. per 100 sft of the roof area.payment is taken as Rs. per 100 sft of the roof area.

8 = REINFORCEMENT STEEL / 8 = REINFORCEMENT STEEL / GENERAL STEEL WORKGENERAL STEEL WORK

Steel is provided separately from R.C.C. Steel is provided separately from R.C.C. per ton, per Kg, or per cwt (standard per ton, per Kg, or per cwt (standard weight also called weight also called Quintal or century Quintal or century weightweight equal to 112 Ibs = 50Kg). equal to 112 Ibs = 50Kg).

Quantity of steel can either be worked Quantity of steel can either be worked out by out by rules of thumb practicerules of thumb practice or by or by intensive calculationsintensive calculations taking the length taking the length and diameter of steel bars from the and diameter of steel bars from the working drawings showing reinforcement working drawings showing reinforcement details and bar-bending schedules. In details and bar-bending schedules. In taking length of bars, due margin of taking length of bars, due margin of hooks, bends and overlappinghooks, bends and overlapping is given is given

REINFORCEMENT STEEL / GENERAL STEEL REINFORCEMENT STEEL / GENERAL STEEL WORK (-ctd-)WORK (-ctd-)

As a As a Rule Of Thumb PracticeRule Of Thumb Practice, , for for ordinary beams and slabs for residences, ordinary beams and slabs for residences, assume 6.75 Ibs of steel per cft of R.C.C. work. assume 6.75 Ibs of steel per cft of R.C.C. work. However, for R.C.C. columns, it varies from 8 to However, for R.C.C. columns, it varies from 8 to 10 Ibs per cft., because normally, we use 2% of 10 Ibs per cft., because normally, we use 2% of steel in columns. steel in columns.

Percentage of steelPercentage of steel means, area of steel divided means, area of steel divided by total area of the column multiplied by 100 by total area of the column multiplied by 100 and 1% of steel in columns corresponds to a and 1% of steel in columns corresponds to a quantity of 4.5 Ibs/cft.quantity of 4.5 Ibs/cft.

9 = FLOORS9 = FLOORS Cement concrete floors. Mosaic floors, and brick Cement concrete floors. Mosaic floors, and brick

floors are most commonly used. floors are most commonly used.

Payments are made separately for different Payments are made separately for different layers, like, topping, lean concrete, sand filling, layers, like, topping, lean concrete, sand filling, earth filling, etc.earth filling, etc.

Earth filling, sand filling and lean concrete are Earth filling, sand filling and lean concrete are paid by volume, whereas, topping is paid on paid by volume, whereas, topping is paid on area basis, mentioning thickness in the area basis, mentioning thickness in the description. description.

Standard unit for payment of topping is, usually, Standard unit for payment of topping is, usually, Rs. per 100 sft.Rs. per 100 sft.

The The skirtingskirting is estimated in running ft. is estimated in running ft.

10 = PLASTERING10 = PLASTERING The type of plaster, proportioning of materials The type of plaster, proportioning of materials

and minimum thickness of plaster have to be and minimum thickness of plaster have to be specified. specified.

The quantity is calculated for total wall surface The quantity is calculated for total wall surface without deduction for openings such as doors without deduction for openings such as doors windows, ventilators, etc. However, if the wall is windows, ventilators, etc. However, if the wall is being plastered on both the faces, the being plastered on both the faces, the deductions for opening areas are made from one deductions for opening areas are made from one side only. side only.

Standard unit for payment is Rs. per 100 sft.Standard unit for payment is Rs. per 100 sft.

HeightHeight is also specified for plastering because, is also specified for plastering because, for greater heights, labor cost increases. The for greater heights, labor cost increases. The rate varies according to the number of the storey rate varies according to the number of the storey

11 = WOODWORK/CARPENTRY11 = WOODWORK/CARPENTRY

The type of material used and the quantity of The type of material used and the quantity of finish required should be clearly indicated in the finish required should be clearly indicated in the description of the item. description of the item.

The rate for any type of woodwork includes The rate for any type of woodwork includes cutting of timber to required sizes, joinery work, cutting of timber to required sizes, joinery work, fittings and fastenings, three coats of oil paints fittings and fastenings, three coats of oil paints or varnish, bolts, locks, handles, etc. or varnish, bolts, locks, handles, etc.

The measurements are taken for the overall The measurements are taken for the overall area of doors, windows, etc.area of doors, windows, etc. If volume of timber If volume of timber required for these items is to be finding out, the required for these items is to be finding out, the computed area is multiplied with the nominal computed area is multiplied with the nominal thickness and an allowance of 25% is made for thickness and an allowance of 25% is made for wastage of timber.wastage of timber.

WOODWORK/CARPENTRY (-ctd-)WOODWORK/CARPENTRY (-ctd-) Rectangular wooden beams, vertical Rectangular wooden beams, vertical

columns, trusses, etc., are measured in columns, trusses, etc., are measured in cft. cft.

Wooden stairs are measured in number of Wooden stairs are measured in number of steps and description of the item includes steps and description of the item includes the riser, tread, and width of the steps. the riser, tread, and width of the steps.

Wooden shelves are measured in running Wooden shelves are measured in running ft (RFT).ft (RFT).

12 = PLUMBING WORK/SANITARY FITTINGS12 = PLUMBING WORK/SANITARY FITTINGS

For water supply and drainage works in a For water supply and drainage works in a building, the pipe lines and sewer lines are building, the pipe lines and sewer lines are measured in RFT, while other items are measured in RFT, while other items are measured in numbers.measured in numbers.

These items include wash hand basins (W.H.B.), These items include wash hand basins (W.H.B.), kitchen basins (which may be of glazed kitchen basins (which may be of glazed ceramic, mosaic, or stainless steel), water ceramic, mosaic, or stainless steel), water closets (W.C., which may be of European type, closets (W.C., which may be of European type, or local type), flushing tanks (also known as or local type), flushing tanks (also known as flushing cisterns), shower rose, and all type of flushing cisterns), shower rose, and all type of water tapes.water tapes.

PLUMBING WORK/SANITARY FITTINGS (-ctd-)PLUMBING WORK/SANITARY FITTINGS (-ctd-) Within sewer lines, Within sewer lines, man holes or inspection chambersman holes or inspection chambers are are

to be provided at every corner and also at a distance, not to be provided at every corner and also at a distance, not exceeding every 50 ft inside the house and every 100 ft exceeding every 50 ft inside the house and every 100 ft outside the house. outside the house.

The The size of man holesize of man hole may be may be 2.5ft X 2,5ft2.5ft X 2,5ft for low depths for low depths and 3ft X 3ft, 4ft X 4ft or 5ft X 5ft for deep depths. and 3ft X 3ft, 4ft X 4ft or 5ft X 5ft for deep depths.

Drainage pipe lines outside the covered area but inside the Drainage pipe lines outside the covered area but inside the boundary wallboundary wall are, usually, of R.C.C. with minimum are, usually, of R.C.C. with minimum diameter 4 in, however, these are available in different diameter 4 in, however, these are available in different sizes. sizes.

Inside the buildingInside the building, drainage pipe is, usually, of C.I. with , drainage pipe is, usually, of C.I. with minimum diameter 3 in. minimum diameter 3 in.

Water supply pipes are, usually, G.I. pipes., estimated in Water supply pipes are, usually, G.I. pipes., estimated in RFT in different dias. RFT in different dias.

Other accessories, like sockets, elbows, tees, reducers, Other accessories, like sockets, elbows, tees, reducers, unions, etc., are estimated in numbers. unions, etc., are estimated in numbers.

13 = ELECTRIC FITTINGS13 = ELECTRIC FITTINGS

• All the accessories used in electric All the accessories used in electric fittings are described in detail and fittings are described in detail and payment is done in numbers or RFTpayment is done in numbers or RFT..

• All All wires and pipeswires and pipes are taken in RFT are taken in RFT while other items are taken in No’s.while other items are taken in No’s.

SOME COMMON RELATIONS SOME COMMON RELATIONS USED IN BUILDING USED IN BUILDING

ESTIMATESESTIMATES

1- MORTARS

(a)Cement-Sand Mortars120 cft dry yields 100 cft wet

(b) Lime-Sand Mortars113 cft dry yields 100 cft wet

(C) Cement-Lime-Sand Mortars112 cft dry yields 100 cft wet

(d) Dry mortar required for 100 sft of ½” thick cement plaster =6 cft

2- CEMENT CONCRETE154 cft dry yields 100 cft wet

3- BRICKWORK

(a) 100 cft Brick masonary Bricks ------------1350Dry Mortar ------- 30 cftWet Mortar ------- 25 cft

(b) 100 sft surface area using bricks on bedBricks --------------360Mortar ------------- 9 cft

(b) 100 sft surface area using bricks on edgeBricks --------------540Mortar ------------- 13 cft

4- POINTING PER 1000 SFT AREA

Ingredient 1:1 1:2 1:3

Cement 8 cft 5 cft 3.8 cft

Sand 8 cft 10 cft 11.4 cft

5- EARTHWORK

Output of labor assuming one man working 8 hours per day with lift up to 5 ft or less

TYPE OF SOIL EXCAVATION PER DAY

Medium Soil 75 – 100 cft

Hard / Stiff Soil 50 – 75 cft

Rocky Soil 25 – 30 cft

6- BITUMEN

Bitumen for 100 sft of DPC (first coat) = 15 Kg

Bitumen for 100 sft of DPC (second coat)

= 10 Kg

7- CEMENT

1 Bag ------------- 50 Kg (Weight), 1.25 cft (Volume)

8- SPECIFIC WEIGHTSRCC --------------- 150 lbs / cft

PCC --------------- 145 lbs / cft

Aggregate ------- 166 lbs / cft

9- TIMBER

Timber for 100 sft of Panelled Doors and Windows = 13 cft

Timber for 100 sft of Glazed windows and Ventilators = 8 cft

10- WHITE WASH

Lime for 100 sft of white wash (one coat) = 1.00 Kg

FOUNDATIONSFOUNDATIONS

SPECIFICATIONSSPECIFICATIONS Clear height of roomsClear height of rooms: : 12’12’ Clear height of VerandahClear height of Verandah: : 10’-0”10’-0” Plinth levelPlinth level: : 1’-6”1’-6” Thickness of roof slabThickness of roof slab: : 4”4” Thickness of RCC shadeThickness of RCC shade: : 3”3” Depth of RCC Beams in VerandahDepth of RCC Beams in Verandah:: 1’-6” below verandah slab 1’-6” below verandah slab Parapet wallParapet wall: : 1’-0” (Clear height above roof tiles)1’-0” (Clear height above roof tiles) Ventilators (4 No.)Ventilators (4 No.): : 2’-6” x 1’-6”2’-6” x 1’-6” RCC lintelRCC lintel: : 6” in depth6” in depth Damp proof coarseDamp proof coarse: : 1 ½”thick PCC (1:2:4) + 2 coats of hot 1 ½”thick PCC (1:2:4) + 2 coats of hot

bitumen + polythene sheetbitumen + polythene sheet Full foundationFull foundation up to plinth level along verandah periphery is up to plinth level along verandah periphery is

providedprovided Internal finishesInternal finishes:: Three coats of white wash/distemper paint Three coats of white wash/distemper paint External finishesExternal finishes:: Three coats of Weather shield paint Three coats of Weather shield paint

Center to Center LengthsCenter to Center Lengths

L1 =L1 = (10’-0”) + (12’-0”) + (0’-4 ½”) + (0’-4 ½”) + (10’-0”) + (12’-0”) + (0’-4 ½”) + (0’-4 ½”) + (0’-4 ½”) = (0’-4 ½”) = 23’-1 ½”23’-1 ½”

S1& S2 =S1& S2 = (12’-0”) + (0’-4 ½”) + (0’-4 ½”) = (12’-0”) + (0’-4 ½”) + (0’-4 ½”) = 12’-9”12’-9”

S3 =S3 = (8’-0”) + (0’-4 ½”) - (0’-4 ½”) = (8’-0”) + (0’-4 ½”) - (0’-4 ½”) = 8’-0”8’-0”

House Estimation

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