INTRODUCTION TO ESTIMATING
CONSTRUCTION COST ENGINEERING
BUILDING CONSTRUCTION ESTIMATING – is the determination of probable construction costs of any given project.
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Estimator who can visualize the project and accurately determine its cost will become one of the most important
persons in any construction company.
The estimators begin their career doing quantity takeoff; as they develop experience and judgement, they develop
into estimators.
DESIGN PROCESS
1. CONCEPTUAL ESTIMATE
 used early in the design process to check and see of the owner’s wants are in line with their budget.
It is often used as a starting point to begin contract negotiation.
2. PRELIMINARY ESTIMATE
 In this point of design process, the contractor prepares and maintain a cost estimate based on the current,
but incomplete design. Contractors may prepare estimates that are used to select between building
materials and to determine whether the cost to upgrade the materials is justified.
ESTIMATING METHOD
The required level of coupled with amount of information about the project that is unavailable will dictate the type of
estimate that can be prepared. These estimating methods required different amounts of time to complete and produce
different level of accuracy for the estimate.
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Detailed Estimating
Assembly Estimating
Square-foot Estimating
Parametric Estimating
Model Estimating
Project Comparison Estimating
DETAILED ESTIMATE
• Includes determination of the quantities and costs of everything that is required to complete the project -materials, labor, equipment, insurance, bonds, and overhead, as well as an estimate of the profit
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To perform this type of estimate, the contractor must have a complete set of contract documents
ASSEMBLY ESTIMATE
• Rather than bidding each of the individual components of the project, the estimator bids the components in
groups known as assemblies. The components of an assembly may be limited to a single trade or may be installed
in many different trades.
• Can be prepared in hours instead spending days preparing detail estimate; however it has many broad
assumptions and less accurate.
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SQUARE-FOOT ESTIMATE
It is prepared by multiplying the square footage of a building by cost per square foot and then adjusting the price
to compensate for differences in the building heights, length of the building perimeter, other building components
The information required is much less than is needed to prepare detailed estimate
It is helpful to check whether the project, as designed, is within the owner’s budget
PARAMETRIC ESTIMATE
• Use equations that express the statistical relationship between building parameters and the cost of the building.
• May include the gross square footage, number of floors, length of perimeter, percentage of the building that is
common space and so forth.
MODEL ESTIMATING
• Uses computer models to prepare an estimate based on the number of questions answered by the estimator
• Similar to assembly estimating, but it requires less input from the estimator.
PROJECT COMPARISON
• Prepared by comparing the cost of proposed project to a completed project.
• The estimator starts with the costs of a comparable project and then makes adjustments for differences in the
project.
ESTIMATING OPPORTUNITIES
1. Architectural Offices
2. Engineering Offices
3. General Contractor
4. Estimating with Quantities Provided by the Designer
5. Subcontractors
6. Material Suppliers
7. Manufacturers’ Representatives
8. Project Management
9. Government
10. Professional Quantity Surveyors
11. Freelance Estimators
12. Computer Software
To be able to do quantity takeoffs, the estimator must:
1. Be able to read and quantify plans
2. Have knowledge of mathematics and a keen understanding of geometry.
3. Have the patience and ability to do careful, thorough work.
4. Be computer literate and use computer takeoff programs.
To be an estimator, an individual needs to go a step further. He or She must:
1. Be able, from looking drawings, to visualize the project through its various phases of construction.
2. Have enough construction experience to possess a good knowledge of job conditions, including methods of
handling materials on the job, the most economical methods of construction and labor productivity
3. Have sufficient knowledge of labor operations and productivity to thus convert them into costs on a project.
4. Be able to keep a data base of information on costs of all kinds including those of labor, material, project overhead,
and equipment, as well as knowledge of the availability of all the required items.
5. Be computer literate and know how to manipulate and build various databases and use spreadsheet programs and
other estimating software.
6. Be able to meet bid deadlines and still remain calm
7. Have a good writing and presentation skills.
TYPES OF BIDS
Basically there are two bidding procedures by which contractors get to build a project for the owners.
1. Competitive Bid
2. Negotiated Bid
TYPES OF BIDS
1. COMPETITIVE BID
 Involves each contractor submitting a lump-sum bid or a proposal in competition with other contractor
to build the project.
 The project may be awarded based on the price or best value.
BASED ON PRICED
• The Lowest Lump-sum bidder is awarded the contract to build the project as long as the contract to build the
project as long as the bid form and proper procedures have been followed and this bidder is able to attain the
required bonds and insurance .
BASED ON BEST VALUE
• The proposals from the contractors are rated based on specified criteria with each criterion given a certain
percentage of the possible points. The criteria may include review of the capabilities of the assigned project team,
the company’s capabilities and its approach to the project (including schedule), proposed innovation method of
mitigating risk and price.
2. NEGOTIATED BIDDING
 Parties arrive at mutually agreed upon price, terms and conditions, and conceptual relationship
 Often used when owners know which contractor they would like to build the project.
 The biggest disadvantage of this arrangement is that the contractor may not feel the need to work quite
as hard to get the lowest possible prices as when a competitive bidding process is used.
CONTRACT DOCUMENTS
The bid submitted for any construction project based on the contract documents. If the estimator is to prepare complete
and accurate estimate, he or she must become familiar with all documents.
CONTRACT DOCUMENTS
1. INVITATION TO BID. The invitation to bid invites potential contractors to bid on the project and provides brief
summary of the project, including project scope and size, location, project’s owner and so on.
2. INSTRUCTION TO BIDDERS. The instructions to bidders provides bidders with the procedures that must be
followed to submit a complete bid and contains such information as the date, time, and place the bid is due,
attendance at pre bid meetings, and so on.
3. BID FORM. The bid form is a standard form that all contractors use to submit their bids.
4. OWNER-CONTRACTOR AGREEMENT. formalizes the construction contract, and it is the basic contract;
incorporates by reference all of the other documents and makes them part of the contract; also states the
contract sum and time allowed to construct.
5. GENERAL CONDITION. define the rights, responsibilities, and relations of all parties to the construction
contract.
6. SUPPLEMENTARY GENERAL CONDITIONS. Used to amend or supplement portions of the general conditions
because conditions vary locality and project.
7. TECHNICAL SPECIFICATION. Written instructions concerning project requirements that describe the quality of
materials to be used and their performance.
8. WORKING DRAWINGS.(Drawings, Illustrations) from which the project is to be built are the working drawings;
containing the dimensions and locations of building elements and materials required and delineate how they
fit together.
9. ADDENDA.Is a drawing or information that modifies the basic contract documents after they have been issued
to the bidder, but prior to the taking of bids. They may provide clarification, correction, or changes in the
other documents.