ESTIMATING IN BUILDING

Instructor’s Manual for

ESTIMATING IN BUILDING

CONSTRUCTION

Ninth Edition Steven J. Peterson Frank R. Dagostino

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Chapter 1 Introduction to Estimating

6 Chapter 1—Introduction to Estimating

LEARNING OBJECTIVES

Gain an overall picture of estimating including the difference types of estimates, the careers available to estimators, what it takes to be a successful estimator, and what comprises the contract documents on which the estimate is based.

ACTIVITIES

• Invite an estimator from industry to discuss his or her job with the students. Have him or her answer

the following questions:

• How does he or she go about estimating a project?• What are the different types of estimating method he or she uses?• What roll does estimating play in the success of his or her company?• What does it take to be a successful estimator?Encourage them to tell estimating related stories.

• Discuss Problems 11 and 12 from the chapter.

INSTRUCTIONAL RESOURCES

PowerPoint Slides: Chapter 01.ppt

SOLUTIONS TO THE REVIEW QUESTIONS

• What information is contained in the working drawings?

The working drawings are the actual plans (drawings, illustrations) from which the project will be constructed. Those drawings contain the dimensions and locations of building elements, the materials required, and delineate how they fit together.

• What information is contained in the technical specifications?

The technical specifications are written instructions concerning project requirements that describe the quality of materials to be used and their performance.

• What is the relationship between the working drawings and the technical specifications?

The working drawings usually contain information relative to design, location, dimensions, and construction of the project, while the technical specifications are a written supplement to the drawings and include detailed information pertaining to materials and workmanship.

• How does the work involved in being an estimator for a general contractor differ from that of an

estimator who works for a subcontractor?

The estimator for the general contractor is responsible for a detailed estimate for the whole project.They must compile costs on everything that is integrated into the project and put it together into a bid for the entire project. An estimator for a subcontractor will prepare an estimate only for the part 2 / 4

Chapter 1 Introduction to Estimating

7 of the project for which they will be involved. For example they may be bidding only the masonry on the project.

• What is the difference between doing a quantity takeoff and doing a full detailed estimate?

A quantity takeoff (QTO) is an estimate of the amount of in place materials required for the construction of a project. A full detailed estimate is an estimate that covers everything required for the construction of the project and includes both costs and quantities for materials, labor, and equipment and subcontractor costs.

• What additional skills must the estimator have to be able to take a quantity survey and turn it into a

detailed estimate?

• Be able, from looking at the drawings, to visualize the project through its various phases of

construction.

• 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.

• Have sufficient knowledge of labor operations and productivity to thus convert them into costs

on a project.

• Be able to keep a database 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.

• Be computer literate and know how to manipulate and build various databases and use

spreadsheet programs and other estimating software.

• Be able to meet bid deadlines and still remain calm. Even in the rush of last-minute phone calls

and the competitive feeling that seems to electrify the atmosphere just before the bids are due, estimators must “keep their cool.”

• Have good writing and presentation skills.

• What is the difference between competitive and negotiated bidding?

Competitive bidding involves each contractor submitting a bid in competition with other contractors to build the project. In most cases the lowest bidder is awarded the contract to build the project as long as the bid form and proper procedures have been followed and the contractor is able to attain the required bonds and insurance. Negotiated bidding involves the contractor working with the owner (or through the owner's architect-engineer) to arrive at a mutually acceptable price for the construction of the project. It often involves negotiations back and forth on materials used, sizes, finishes, and other items which affect the price of the project.

• What is the difference between a detailed estimate and a square-foot estimate?

The detailed estimate includes determination of the quantities and costs of everything required to complete the project. This includes the materials, labor, equipment, insurance, bonds, and overhead, as well as an estimate of profit. Square-foot estimates are prepared by multiplying the square footage of a building by a cost per square foot and then adjusting the price to compensate for differences in the building heights, length of the building perimeter, and other building components.Square-foot estimates require less information to prepare and are less accurate.

• What are the contract documents, and why are they so important? 3 / 4

Chapter 1 Introduction to Estimating

8

The contract documents consist of the invitation to bid, instructions to bidders, bid form, owner- contractor agreement, general conditions of the contract, supplementary general conditions, technical specifications, and the working drawings, including all addenda incorporated in the documents before their execution. All of these taken together form the contract. These documents provide the legal basis for the construction of the project.

• Why is it important to bid only from a full set of contract documents?

It is important to bid from a full set of contract documents to be certain you have all of the required information. If part of the documents are missing that portion of the project would most likely be left out of the bid. Errors of omission can be catastrophic for a contractor.

• For this assignment you will explore the role estimating plays in the construction industry by

interviewing a person whose job duties include estimating. Begin by setting up an interview with an estimator, project manager, project engineer, superintendent, foreperson, architect, engineer, construction material salesperson, or freelance estimator. During the interview, ask the person the following questions and ask follow-up questions as necessary. Be respectful of their time and limit your interview to 20 minutes, unless the person offers to extend the interview. Be sure to thank the person before you leave and mail them a thank you note within 48 hours of the interview. After the interview, prepare written responses to the following questions and be prepared to discuss your

findings in class, if your instructor chooses to do so:

• What are the estimates used for (ordering materials, preliminary budget, etc.)?
• At what stage of the construction process (early-design, late-design, bidding, construction, etc.)

does the estimate occur?

• What are the consequences if the estimate is slightly wrong? If it is very wrong?
• How do they prepare an estimate? After the interview, decide which estimating method

(detailed, assembly, square-foot, parametric, model, or project comparison) best describes the type of estimates he or she prepared.

• How long does it take to prepare an estimate?
• What skills are required to become a good estimator?
• What experience is required to get a job like his or hers?

The answers to these questions will vary from interviewee to interviewee.

• Review a copy of the contract documents (drawings and project manual) for a construction project.

Contact documents may be reviewed at a contractor’s, subcontractor’s, architect’s, or engineer’s office or may be downloaded from the Internet. Write a brief summary of how the contract documents are organized. Be sure to discuss both the project manual and the drawings. Be prepared to discuss your findings in class, if your instructor chooses to do so.

The answers to this question will vary from project to project.

• Using the Warehouse.xls Excel file that accompanies this text, determine the estimated cost of a

warehouse with the following parameters:

Building length—210 feet Number of bays on the length side of the building—7 each Building width—120 feet Number of bays on the width of the building—4 each Wall height above grade—22 feet Depth to top of footing—12 inches Floor slab—6 inches thick with wire mesh Number of roof hatches—2 each Number of personnel doors—4 each Number of 14-foot-wide by 14-foot-high overhead doors—14 each Number of 4-foot by 4-foot skylights—28 each

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