An estimate is calculation or computation of the quantities of materials needed for a particular work and expenses likely to be incurred in the execution of the work.
- To assess the financial requirements.
- For obtaining the approval and sanction of component authority.
- To access the economic feasibility of the project.
Types of estimates
- Preliminary estimate or rough cost estimate.
- Detailed estimate
- Revised estimate
- Supplementary estimate
- To decide the financial involvement for AS by the authority.
- Cost of major components should be shown separately.
- Brief report and site plan needed.
- Prepared based on practical knowledge and similar works undertaken in the past.
- Based on the plan and sectional drawings.
- Details of the works.
- Quantities of different items of works.
- Cost of each item.
- Contingencies etc.
- It also a detailed estimate.
- Prepare when original sanctioned estimate is likely to exceed during the execution of work.
- New components incorporated.
- Detailed estimate of the additional work.
- Is prepared when additional works are required to supplement the original work.
Preparation of estimates
- Rates of items are worked out based on detailed data providing cost of materials, conveyance charges and labour as per schedule.
- The data book deals with the quantities of materials and labour required for different items of work.
- Will remain unchanged by fluctuation in market rates.
SOR-Schedule of Rates
- Prepared by the chief engineer PWD Administration.
- Data from economics and statics department and current market rates are taken into account.
- Is for estimating purpose.
- Followed for original and maintenance works.
- Consist of 2 volumes.
- Actual distances are used.
- Taluk conveyance not used.
- Certificate- “The distances noted in the data for conveyance from quarry or source have been personally verified by me and are found correct. These are the minimum leads require.
- Rates available for lorry load, head load and boat load.
- For hilly areas 15% increase in rates are allowed.
- Lead or distance for removal-horizontal distance between the vertical central line of the pit cross section and the bank which is formed with the excavated material.
- Measured in units of 50m.
- Shortest practicable route.
- Vertical distance.
- ½ depth of the pit excavated +½ the height of bank formed with excavated earth + difference in level between the top of the pit and bottom of the bank.
- Excavation in difference material to be estimated separately.
- Ordinary soil- Any material yield to the application of mammati, spade or shovel.
- Hard soil- Any material which requires the application of picks or scarifies to loosen.