Estimation and Costing! What is quantity surveying and estimating?, What are the type and purposes of estimation?, What are D.S.R. and S.S.R.?, List of item of work, Format of face sheet, measurement sheet and abstract sheet.

Quantity Surveying:- 

• Quantity Surveying is a part of estimation in which calculating the quantity of all the materials needed to build any structure.

Estimation:-

• In this process, If any structure is to be constructed, then calculate all the quantities of the material and their cost required to construct it.

Valuation:-

• Valuation means calculating the present marketable cost of any structure.

Purposes of estimation:-

• Estimation helps you know the approximate quantities of various materials required in any project.
• Estimation helps to know the approximate cost of any project.
• It helps financial planning.
• To know the approximate project time.
• The estimations used to obtained administrative approval and the sanction of proposed work.
• It helps to invite tenders.
• Estimation helps you know the number of labour required for the completion of work.
• It is used to know the requirement of tools and equipment for particular work.

Types of estimate:-

A) Approximate estimate:-

• It is also known as Preliminary or Rough estimation.
• Preliminary or rough type of estimate is prepared to know the approximate cost of any work.
• Based on practical field experience.
• Following are the different method of approximate estimation of building:-

  1) Plinth area rate method:- 

• It is a part of the rough estimate.
• The plinth area is the covered area of the building and is measure at the floor level of each storey.
• Plinth area rate estimate = Plinth area of building × Plinth area rate

  2) Cubic content method:-

• It is an approximate estimate.
• The cubic rate is determining by the cost of a building having similar construction in that area.
• Approximate cost of building = Volume of building (cubical content) X Rate per unit volume (cubic rate)

  3) Service unit method:-

•  In this method, all cost of unit quantity is considered for calculating approximate estimates.
• For example,

        For school = service unit is per classroom.
        For hospital = service unit is per bed.

• Approximate cost = Number of service unit × cost per service unit

  4) Bay method:-

• Bay method is used for the similar parts of a structure.
• It is used for factory building, railway platform, go-downs, etc.
• Approximate cost = N. of bays X Cost of one bay

          N. of bays - Number of bays
  5) Approximate quantity method:-

• Approximate quantity method is a part of the approximate method.
• The plan or line plan of the building must be required in this method.
• In this method, the running meter cost of the foundation and superstructure first be calculated, and then the running rate is multiplied by the total length of the wall.

B) Detailed estimate:-

• It is an accurate method.
• Detailed estimates are prepared based on the drawing plan, which includes length, width, and height.
• This estimate is required to sanction from the technical authority of the engineering department of the government.
• Following factors to be considered during preparation of detailed estimate:-

        1) Specification

        2) Quantity and availability of the material

        3) Transportation of material

        4) Location of site

        5) Labor component

        6) Nature of work

• Types of detailed estimate:-

1. Revised estimate:-

• A revised estimate is a part of the detailed estimate.
• A revised estimate is prepared under any one of the following condition:-

1. When approved estimate is more than 5%.
2. When the cost of the work more than 10% of the administrative sanctioned amount.
3. If there is a changing number of materials.

     2. Supplementary estimate:-

• It is a type of detailed estimate.
• A supplementary estimate is prepared when additional work is required along the running project.

     3. Revised and Supplementary estimate:-

• It is a type of detailed estimate.
• Revised and supplementary estimates are used when deviations in material, planning and changes in construction or item of work.

     4. Annual maintenance or repair estimate:-

• It is prepared to maintain the structure in a safe condition.
• The annual repair of the building provides for 1.5% of the original cost of the building.

List of Item of Work:-

A) List of different items of work in load bearing structure:- 

1. Site clearance
2. Excavation for foundation
3. P.C.C. in foundation
4. U.C.R. masonry in foundation
5. C.R. masonry in plinth
6. D.P.C. at plinth level
7. Plinth filling
8. Brick work in superstructure
9. Providing and fixing door and window frame
10. Lintel over opening
11. Roof 
12. External and Internal wall plastering
13. Flooring
14. Water supply and Sanitary arrangement
15. Electrification

B) List of different items of work in framed structure:-

1. Site clearance
2. Excavation for foundation
3. P.C.C. in foundation
4. R.C.C. in footing 
5. Plinth beam
6. Column
7. Floor beam
8. Slab
9. Staircase 
10. Plinth filling
11. Brickwork in superstructure
12. Providing and fixing door, window frame and shutter
13. External and Internal wall plastering
14. Water supply and Sanitary arrangement
15. Electrification
16. External and Internal wall painting

Face sheet:-

• The face sheet is attached to the cover of the prepared detailed estimate.
• The face sheet includes following item:-

1. Introduction of Organization
2. Total budget of project
3. Objective of project work
4. Method of estimate followed
5. Time required for completion of project work
6. Fund required for project 
7. All other charges, EMD, Security Deposit.

• Format of face sheet:-

   

Measurement sheet:-

• The measurement sheet is used to giving the exact total quantity for each item.
• Format of measurement sheet:-

   

Abstract sheet:-

• It is also known as BOQ (Bill of Quantity)

   

Schedule of rates:-

 1) District Schedule Rate (D.S.R.)

• District Schedule Rates in the form of the printed book.
• This booklet contains the rates of each district for various items of civil engineering work such as cost of material, labour, transportation charges, etc.
• District schedule rates booklet is published by the public work department for the different region.
• The district scheduled rates is revised every year because of the change in the cost of the material and labour wages every year.

 2) State Schedule Rates (S.S.R.)

• State schedule rates are applicable for a particular State.
• While preparing the rates for S.S.R., the basic rates of all the district are considered at average level.