Professional PracticesCE-428

The EstimateLecture 4

Organisation

• The estimator must maintain a high degree of organization throughout the estimate development stage

• A well organised estimate improves the probability of getting the work, facilitating the actual work in the field, and completing the work within budget

• The estimator’s work must be kept organised to the extent that in an unforeseen circumstance (such as illness or accident), someone else might step in, complete the estimate, and submit a proposal on the project

The Estimating ProcessFigure 4.1

Planning the Estimate

• When and how will the work be done

• Who is responsible for activities

• Bar Chart Schedule may be used

Bar Chart ScheduleFigure 4.2

Estimating Notebook

• A notebook should be kept for each estimate prepared. The notebook should be broken down in to several areas which may include:

– Workup sheets– Summary sheets– Errors and omissions sheets– Listing of calls made to the architect / engineer

• Every page of the estimate should numbered and initialed by the person who prepared the estimate

To Bid or Not To Bid

• It is not possible for the contractor to submit a proposal for every project that goes out to bid

• The contractor finds out what projects are out for bid and then must decide on which projects to submit a proposal

• The contractor must consider the following factors before submitting a proposal:– Type of construction involved– Location of the project– Size of the project in terms of total cost

The Estimate• Once the contractor makes a decision to bid on a particular project,

arrangements are made to pick up the contract documents

• The accuracy for the estimate must be in the range of 98 to 99 % for all major items on the estimate

• Listed below are involved in working up a detailed estimate. – Drawings and the project manual should be carefully checked for completeness– Get yourself acquainted and get a feel for the project. How large is it? What

shape is it? What are the principal materials?– Review the floor plans, room layouts– Review wall sections to see what materials are being used– Review structural drawings

The Estimate

– Review mechanical (plumbing and HVAC) drawings– Read and study the project manual– Visit the site• Take pictures

– Review general conditions and supplementary general conditions making a list of all items contained in the project manual that will affect the cost of the project

The Estimate

– Order:• Insurance• Bonds

– The estimator should now begin the take off of the quantities using workup sheets

– Ask subcontractors and materials suppliers to bid– List all overhead items required

The Estimate

– Summarize costs from workup sheet on the summary sheet

– Check for errors– Verify with architect/engineer:• That you have received all of the addenda• Time and place of bid

Common Errors to Check

• Math errors (+, -, x, /)• Omission of items (material, labor, equip,

overhead)• Time to complete the project• Errors in estimating construction waste• Errors in estimating quantities of material• Transferring number from one sheet to another

Common Errors to Check

• Adding a line to a spreadsheet and not checking to make sure that the new line is included in the total

• Set up errors in software– Formulas

• Improper use of software since the user does not understand the limits of the software or the inputs required by the software

Site Investigation (Visit)

• Site access• Availability of utilities

(electric, water, telephone)

• Site Drainage• Transportation facilities• Required protection or

foundation of adjacent property

• A rough layout of the site locating the proposed storage and equipment locations

• Subsurface soil conditions (bring a post hole digger to check this)

• Local ordinances– Permits – Licenses– Fences

• Local labor and union rules

Site Investigation (Visit)

• Local material and delivery pricing• Subcontractor availability• Road conditions to the project• Housing and food facilities• Banking facilities

Specialty Contractors

• Is a separate subcontractor hired by the prime contractor to perform certain portions of the work. e.g. plumbing, electrical, HVAC

• Advantages:– Less direct-hire craft personnel– Reduced risk

• Disadvantage:– Less control

• Bid Tabulation (see Fig. 4.4 for Subcontract)

Materials

• For each project being bid, the contractor will request quotations from materials suppliers and manufacturers’ representative for all materials required

• Quote should include:– Material cost– Freight (cargo, shipment)– Taxes– Delivery time– Terms of payment

Estimating Sheets

• Workup sheet– Used to make “work up” the cost of each item

(See Fig. 4.6 Estimate Workup Sheet – Reinforcing Steel

• Takeoff be complete, do not write e.g. “wire mesh” but “wire mesh 6x6– If mesh is galvanized, it will increase your material

cost by about 20%

Estimating Sheets

• Summary sheet– Summarized cost on workup sheets– List all the information required • but none of the calculations and sketches of the

workup sheet.

– Figure 4.7 is an example of a summary sheet for concrete in the project.

– Figure 4.8 summarize all cost for the project.

Errors and Omissions

• Make list of errors and omissions• Get clarification from architect/engineer• Specifications take precedence over drawings