Followings are common types of estimate -* Detail Estimate
* Unit Based Estimate
* Model Estimate
* Comparison Estimate
* Parametric Estimate
Detail Estimate - This type of estimate includes everything that needs to complete the project as well as overhead and contractor's profit. For this type of estimate, an estimator needs complete set of drawing and instruction manual of the project. This estimate shows required materials, labor, time to complete the project, complete cost details and overhead and also contractor profit. It also includes insurance, bond, equipment and other necessary things that need to complete the project. Estimator for this type of estimating should be experienced person because complete project budget, time duration and contractor profit depends on his visualization.
Unit Based Estimate - This type of estimate is prepared by calculating building area and then multiplying area by predefined unit cost. And then adjusted the cost by considering building height, length, width and other necessary building components. Required documents for preparing this type of estimate is a simple floor plan with measurement and key elevation of the building. This type of estimation is used to check whether the project was designed within owner's budget.
Model Estimate - This type of estimate is prepared based on a model project estimate which is developed before. Preparing this type of estimate needs answering several key questions depending on model project. Such as length and width of building, number of base, size of base, floor height, number of bath etc. Keep in mind that proposed project should be similar to model project. this type of estimate may prepare a details estimate of whole project or a part of project depending on the model project.
Project Comparison Estimate - In this method, an estimator prepares estimate of proposed project by comparing similar completed project. After preparing the comparison estimate, estimator makes adjustment for variation of proposed project with the completed project.
Parametric Estimate - In this type of estimate, an estimator uses equations to prepare the estimate. This equation is the relationship between "parameters" and "cost" of a building project. This estimate is like unit based estimate but more complex than unit based estimate. This type of estimate is done for getting concept of proposed project cost.
There are some other methods are used to determine the project cost in the different location of the world. Nowadays, there are many computer programs available in the market to make the estimation process easy and quick.