Quantity Estimation for Buildings Unit 1 Part 1

Que1.1. What’s estimation? What’s the purpose of estimation? 

Answer  Estimation It’s the process which guides us to determine the cost,   volume, tools,  shops and labours which are  demanded to complete the   design with in time of completion.  Purpose of Estimation Following are the purposes of estimation 

1. To give a nicely Accurate Idea of the Cost An estimate is  necessary to give the  proprietor a  nicely accurate idea of the cost to  help him decide whether the work can be accepted as proposed or  not, depending upon the vacuity of  finances. 

2. Estimating Accoutrements From the estimate of a work it’s possible to  determine what accoutrements ( and in what amounts) will be  needed for  the work so that arrangements to  land them can be made. 

3. Estimating Labour The number and kind of workers of different   orders who’ll have to be employed to complete the work in the  specified time can be  set up out from the estimate. 

4. Estimating Plant An estimate will help in determining the  quantum  and kind of  outfit  demanded to complete the work.

5. Estimating Time The estimate of a work and  once experience enable  one to estimate  relatively  nearly the length of time  needed to complete an  item of work or the work as a whole. 

Que1.2. Describe the types of estimates. 

Answer  Types of Estimates Estimates can be grouped into two main  orders  Approximate Estimates An approximate estimate is an approximate  or rough estimate prepared to  gain an approximate cost in a short  time. 

Detailed Estimates 

1. A detailed estimate of the cost of a  design is prepared by determining  the amounts and costs of everything that a contractor is  needed to   give and do for the satisfactory completion of the work. 

2. It’s the stylish and most  dependable form of estimate. 

3. A detailed estimate may be prepared in the following two ways  Unit-  volume Method 

a. In the unit-  volume  system, the work is divided into as  numerous  operations or  particulars as are  needed. 

b. A unit of  dimension is decided.

c. The total  volume of work under each item is taken out in the  proper unit of  dimension. 

d. The total cost per unit  volume of each item is analysed and worked  out. 

e. also the total cost for the item is  set up by multiplying the cost  per unit  volume by the number of units. 

f. This  system has the advantage that the unit costs on  colorful jobs  can be readily compared and that the total estimate can  fluently be  corrected for variations in amounts. 

ii. Total-  volume Method In this  system, an item of work is divided  into the following five services  Accoutrements,

b. Labour,

c. Plant,

d. Charges, and

e. Profit. 

The total amounts of each kind or class of material or labour are   set up and multiplied by their individual unit cost. also, the cost of  factory, outflow charges and profit are determined.

Que1.3. What are the main  way in medication of estimate? 

Answer  Following are the  way in the medication of an estimate 

1. Taking Out Amounts 

i. In the first step of taking out amounts, the  measures are taken   out from the  delineations and entered on  dimension  distance or dimension  paper. 

ii. The  measures to be taken out would depend upon the unit of   dimension.

For  illustration, in the case of gravestone masonry length,  consistence and height of the walls would be entered on the  dimension   distance, whereas, in the case of publishing only the lengths and height of  the walls would be entered. 

2. Squaring Out The alternate step consists of working out volumes,  areas and so on, and casting up their total in recognised units. 

3. Abstracting 

i. In the third step, all  particulars along with the net results  attained in the  alternate step are transferred from  dimension  wastes to especially  ruled  wastes having rate column ready for pricing. 

ii. The alternate and third  way  over are known as ‘ working up ’.  All  computations in these stages and every entry transferred should be  checked by another person to  insure that no  fine or copying  error occurs. 

Que1.4. What are the principles of deciding unit of   dimension? 

Answer  Following are the principles of selection of unit of  dimension  1. The unit of  dimension should be simple and accessible to measure,  record and understand. 

2. It should be one which provides for fair payment for the work involved. 

3. In the result it should yield amounts which are neither too minute nor  too large. 

4. The price per unit shouldn’t be a  veritably small figure or a  veritably large one,  that is, generally  premium  particulars will be measured in  lower units, cheaper  bones in larger units. 

5. The unit of  dimension may  occasionally depend upon the unit for the  raw material and/ or labour and/ or important  confines. For  illustration,  gravestone masonry is measured in boxy metres because raw accoutrements  are  measured in boxy metres. Publishing or pointing is measured in square  metres as the labour is considerable. 

Que1.5. What are item of  workshop? Write the units  needed to  measure them. 

Answer  particulars of Works Following are the main  particulars of  workshop and their  measure units 

1. Earthwork Earthwork in excavation and channel in  stuffing are   generally taken out independently under different  particulars and amounts are  calculated in m3. 

2. Concrete in Foundation The concrete is taken out in m3 by length  × breadth × consistence. The length and breadth of foundation concrete  are  generally the same as for excavation only the depth or consistence  differs. 

3. smirching When the soil is soft or bad, one subcaste of dry  slipup or gravestone  soling is applied below the foundation concrete. The soling subcaste is   reckoned in m2( length × breadth) specifying the consistence. 

4. Damp Proof Course( DPC) It’s  generally of 2.5 cm thick rich cement  concrete 11.5 3 or 2 cm thick rich cement mortar 1 2, mixed with  standard water proofing material is  handed at the plinth  position to full   range of plinth wall and the amounts are  reckoned in m2( length ×  breadth).  5. Masonry It’s  reckoned in m3( L × B × H). Foundation and plinth  masonry is taken under one item, and masonry in superstructure is  taken under a separate item. 

Que1.6. What are the  colorful  system of estimation? Explain in   detail. 


What are the different  styles of estimation? Which  system you  borrow for octagonal bay front  structure? 

Answer  styles of Estimation for Building Works The estimation of   structure amounts like earth work, foundation concrete, brickwork in  plinth and superstructureetc. can be worked out by long wall-short wall   system and center line  system. 

1. Long Wall- Short Wall Method 

i. In this  system, the wall along the length of room is considered to be long  wall while the wall  vertical to long wall is said to be short wall. 

ii. To get the length of longwall or shortwall, calculate first the centre line  lengths of individual walls. also the length of long wall( out to out) may  be calculated after adding half breadth at each end to its centre line  length. 

iii. therefore the length of short wall measured in to  by and may be  set up by  abating half breadth from its centre line length at each end. 

iv. The length of long wall  generally decreases from earth work to  slipup work  in super structure while the short wall increases. These lengths are  multiplied by breadth and depth to get amounts. 

2. Centre Line Method 

i. This  system is suitable for walls of  analogous cross sections. Then the total  centre line length is multiplied by breadth and depth of  separate item  to get the total  volume at a time. 

ii. When cross walls or partitions or gallery walls join with main wall,  the centre line length gets reduced by half of breadth for each junction. 

iii. similar junction or joints are studied precisely while calculating total centre  line length. The estimates prepared by this  system are most accurate  and quick. 

iv. Center line  system is suitably used for estimating  indirect, blockish,  hexagonal, octagonaletc., shaped  structure . incompletely Centre Line and incompletely Cross Wall Method 

  1. This  system is  espoused when external( i.e., around the  structure) wall is  of one consistence and the internal walls having different  density. In   similar cases, centre line  system is applied to external walls and long wallshort  wall  system is used to internal walls. 
  2. ii. This  system suits for different  density walls and different  position of  foundations. Because of this reason, all Engineering departments are   rehearsing this  system.

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