Estimation is the process or method in which the total cost or the fund required for the construction work is calculated before starting the construction. Simply, we can define it as the mathematical process to find out the probably required fund for the work.
An estimate is used to find out the expected expenditure that could be required to complete the project or that work. It is necessary to know the probable cost to complete the construction work, which consists of the cost of materials, cost of transportation, cost of labor, cost of scaffolding, water, cost of tools and plants, and supervision charges, taxes and reasonable profit of the contractor, etc.
Estimate gives us the probable cost of the work, not 100% exact cost.
Before starting any construction, the owner and the contractor should know the probable cost of the project. If the probable cost of construction work is greater than the budget of the owner, then the cost is reduced by minimizing the expenses or by changing the specifications. So while preparing an estimate, the quantities of different items of work are calculated carefully and from these quantities, the cost is calculated.
The primary motive of estimation is to know the probable cost for the project. The estimator needs to do estimate carefully. Otherwise, if the expenditure exceeds then the estimated cost, it is difficult to arrange additional money. The rate of each item should be reasonable and prefer the present market rates.
The estimated cost may not be exactly to the actual cost but it should be tentative close to the actual cost.
For every engineering works, it is necessary to know the probable cost of construction before starting it so that we have a clear idea of whether we have that much fund or not to perform the work. And we can make changes to the work if the shortage of funds my occurs before starting the works.
Example: Let suppose if the estimation of a project is $10,000 but you have only $8000 then either you have to stop that project or manage the fund or reduce the works.
So, my point is that due to the estimate report you have a clear idea about the projects. Either you have to manage a fund or pull out the project. Also, you can reduce the quantity of work to work within that limited funds.
You want to construct it, know the cost of construction first.
Importance of estimation
The importance of estimation in the civil engineering field is:
- To find out the necessary amount of funds required to complete the proposed works.
- To ascertain the required quantity of materials for the work.
- Preparing schedules and programs for construction work.
- To decide the tools, plants, and equipment required during the work.
- To find out the numbers of workers (Skilled workers / Unskilled workers) required to complete the work.
- For the valuation of the existing property.
- For inviting tender and to prepare a bill for payment.
- It is necessary for public projects to prepare estimation to obtain the administrative approval for the work.
- It gives an idea about the quantity of materials such as the required amount of bricks, cement, steel, etc. required in construction.
- It is also used for the contract proposed.
- For claiming the insurance after damage or destruction.
- For selling or purchase propose of the property.
How to prepare an estimate report?
To prepare an estimate report, you need a detailed drawing of the work which includes all dimensions. Also, detail specifications of workmanship mentioning the property and portion of the material to be used. And, the rate list of the materials. After getting all these data you can prepare an estimation of any work.
During preparing estimate you need to be more precise and accurate and overcome calculation errors.
Data required for Preparation of Estimate Report
1. Drawing of the work: The complete drawing including the dimension is required. On the basis of the drawing, the quantity of materials or items required for work is calculated. So fully drawing of the building or projects including its dimension on it is required.
The drawing must have different views as plan, elevation, and sections. Thus, drawing is the basic requirement for estimation. We cannot start the estimate of any work without drawing because we don’t have any idea for what we are doing the estimate.
2. Rate list: List of the rate of different materials, labors, plants, etc is required to calculate the total required fund for construction. Different materials such as cement, sand, etc requirement for construction purposes may not have the same rate throughout the country or states, it may vary depending upon the availability of materials. Also, the rate of different tools, plants, and workers is needed.
Generally the department of engineering, a government-owned institute used to provide the rate of materials of different locations throughout the country but sometime the rate may differ from the actual market rates. So during preparing estimates, both government rate and market rate are to be considered.
Note: It is not necessary that the rate of materials, labors charge be same throughout the country.
3. Specifications: Specification defines the nature of work to be done. It includes detail about the material, types of material,s and the method of work to do on the site. The contractor has to work according to the specification.
After getting all these data you can easily prepare the estimate report for any projects or works.
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