CONSTRUCTION ESTIMATES: TYPES & OBJECTIVES

What is Construction Estimate?

Construction estimating is the process of identifying the pieces of work that make up a project, as well as the rate at which materials are used to complete the work. This method of predicting aids in comprehending the cost of constructing a building, dam, road, or other structure.

Estimation allows you to get an estimate of how much a project will cost before you start working on it. As a result, it aids in the comprehension of the construction project's feasibility. To achieve high precision and quality, large building projects use a variety of construction estimation methodologies.

Objectives:

The following are some of the most essential goals of estimation in building projects:

1. To determine the extent and viability of a construction project in order to finalize and allocate the money.

2. To assist contractors in making decisions about whether or not to bid on a project.

3. Calculate the project's likely cost.

4. Determine the number of supplies and labor required for the project.

5. To determine when the project will be completed.

6. Maintaining cost control during the project's implementation.

7. To provide assistance with project bidding, tendering, and other technical sanctions.

8. Assisting with the rent, sales procedure, and other aspects of property value.

A proper cost estimate prevents the builder from losing money and assists the customer in avoiding circumstances where they are overcharged. The estimating process aids in the promotion of the earned value management component, which is a project management technique based on the premise of tracking project performance against the overall time and cost estimate of the construction project.

Types of Estimation in Construction

The different types of estimates used in construction are as given below:

1. Rough Cost Estimate

2. Plinth Area Estimate

3. Cubical Content Estimate

4. Item Rate Estimate or Detailed Estimate

5. Revised Estimate

6. Supplementary Estimate

7. Repair and Maintenance Estimate

1. Rough Cost Estimate:

A preliminary or approximate estimate method is often known as a rough cost estimate.

1) A preliminary estimate provides insight into a financial policy issue.

2) Estimate based on practical experience and the cost of similar projects.

3) The preliminary estimates for a road construction project define how much money will be spent on each kilometer of road. The following documents are included in this estimate:

• a. Comprehensive Report
• b. Site plan for the proposal

c. Installation of a power and water supply system

d. Information on land acquisition, etc.

e. The preliminary estimate obtained must be precise enough that only a 10% to 15% variance from the original project cost can be predicted.

2. Plinth Area Estimate

The plinth area estimate is calculated by multiplying the building's plinth area by the country region's plinth area rate. The cost of similar building structures developed in the area is used to determine the rate of plinth area.

1) Rate: Total construction cost divided by plinth area

2) For new construction, the rate is utilized.

3) The following documents are linked to the plinth area estimates:

a. The structure's line plan with brief details.

b. The cost of additional utilities such as electricity and water.

3. Cubical Content Estimate

The cubic contents estimations are calculated by multiplying the plinth area by the building's height. The height refers to the distance between the ground level and the roof's peak. This contains documents that are comparable to the ones described previously.

a. The estimate is based on the projected building's cubical contents.

b. After that, the rate per cubic meter is computed.

c. When compared to the plinth area approach, the cubic content method is more precise.

d. The cubic content rates are based on the cost of similar structures built in the area previously.

4. Item Rate Estimate or Detailed Estimate

a) The most precise estimating approach.

b) The figures are calculated using the building's plan and sections.

c) Building construction work is divided into subheads, such as excavation and foundation. The number of objects that fall under each subhead are calculated in detail using the dimensions of the drawings.

d) The total cost is calculated as the sum of the cost abstracts.

e) The abstract cost estimates list the required quantities as well as the rate for each item. This is appended to the detailed estimate at the end.

f) Along with the estimate, precise specifications and drawings must be given.

5. Revised Estimate

This is a form of a detailed estimate, as well. When the detailed estimate exceeds by 10% due to insufficient rate or other factors, this is generated as a revision of the detailed estimate.

The report must be attached to the revised construction estimate in order to determine the cause of the cost increase.

6. Supplementary Estimate

In construction, a supplemental estimate is a cost estimate for additional work beyond the scope of the original project. This extra work is a project that goes along with the primary work.

7. Repair and Maintenance Estimate

Repair and maintenance estimation is the estimation of a project that mostly consists of repair and maintenance work. The maintenance is usually done once a year. The expected maintenance cost cannot exceed 1.5 percent of the project's total capital cost.

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Conclusion:

The goal of the project and the level of precision required determine the estimation approach. The approach for estimating material supply must be precise, whereas the method for estimating feasibility studies is less precise.