5 COMPLETE THE ESTIMATE

After totaling the material, labor, and subcontracts to get total direct costs, complete the estimate by applying steps 6-12 of the ratio estimating technique described earlier in Section 204.

Example of a Detailed Estimate

Figures 205-4 through 205-6 illustrate a portion of a detailed estimate for the direct costs of installing piping. The format used is that given in Figure 601-1.

Source of the Data The source of the data is the piping section of the offplot tankfield portion of a control (Class 4) estimate. The estimate was prepared in late 1992 by the construction contractor for the Pascagoula Aromax project. The figures on the following pages present this data.

Figure 205-4 gives information on eight-inch piping from the contractor’s estimate (12/92).

A/C Description

Material Labor Sub-

con- tracts Total Quantity Unit Cost Cost Unit Mhs Man-

hours Rate Cost 1701 Field-run CS Pipe/fittings

8-inch Pipe, Linear Feet 1,008 13.15 13,255 1.74 1,754 11.76 20,627 33,882 1704 Shop-fabricated CS Pipe Spools

8-inch Pipe, Linear feet 628 39.12 24,567 1.81 1,137 11.76 13,371 37,938 1709 Valves CS (labor w/pipe)

8-inch 150 Lb Ball Valve 6 3187.00 19,122 8-inch 150 Lb Check Valve 3 847.67 2,543 8-inch 150 Lb Gate Valve 10 987.00 9,870

8-inch 150 Lb Gate Valve w/GO 4 1833.90 7,336 38,871

1772 Tie-ins (mat’l w/pipe)

8-inch, Each 34 35.00 1,190 11.76 13,994 13,994

1773 Hot Taps (mat’l w/pipe)

8-inch, Each 1 6.50 7 11.76 82 82

1773 X-rays

8-inch, Each (Subcontract Cost @ $36)

9 0.50 5 11.76 59 324 383

1781 Hangers/supports - Fabricate & Erect, Lump Sum

1 593 11.76 6,974 6,974

1798 Takeoff Allowance at 5 Percent 82 3,835 234 2,755 16 6,606

1700 Total Direct Cost 80,528 57,862 340 138,730

Figure 205-5 gives the same eight-inch piping, using Richardson Process

Plant Construction Estimating Standards, 1993 edition.

A/C Description

Material Labor Sub-

con- tracts Total Quantity Unit Cost Cost Unit Mhs Man-

hours Rate Cost 15-43 Field-run CS Pipe/fittings

8-inch Pipe, Linear Feet 1,008 15.65 15,775 0.109 110 11.82 1,300 17,075 8-inch Ells, Long Radius, Each 30 76.65 2,300 7.20 216 11.82 2,553 4,853 8-inch Tees, Each 6 105.00 630 10.80 65 11.82 768 1,398 8-inch Weld Neck Flanges, Ea 10 60.90 609 3.60 36 11.82 426 1,035 8-inch 150 Lb Check Valve 3 2082.00 6,246 3.00 9 11.82 106 6,352 8-inch 150 Lb Gate Valve 14 2118.00 29,652 3.00 42 11.82 496 30,148 8-inch 150 Lb Ball Valve 6 2102.00 12,612 3.45 21 11.82 248 12,860 8-inch Field Erection Buttwelds, Ea 113 7.80 881 11.82 10,413 10,413 15-44 Shop Fabricated CS Pipe Spools

8-inch Pipe, Linear Feet 628 15.65 9,828 0.456 286 11.82 3,381 13,209 8-inch Ells, Long Radius, Each 65 195.75 12,724 12,724

8-inch Conc Reducers, Each 4 145.45 582 582

8-inch Tees, Each 15 277.57 4,164 4,164

8-inch Weld Neck Flanges, Ea 40 120.40 4,816 4,816

15-72 Bolts And Gaskets

8-inch 150 Lb Spiral Wound, Sets 50 21.21 1,061 2.00 100 11.82 1,182 2,243 15-74 Hot Taps

8-inch, Subcontract, Each 1 575 575

Mobilization, 60 Miles 75 75

15-75 X-ray of Buttwelds

8-inch, Subcontract, Each 9 351 351

15-76 Hangers/Supports - Fabricate +

Erect, Lump Sum Allowance 1 800 400 11.82 4728 5,528

Takeoff Allowance

At 5 Percent 82 5,090 108 11.82 1277 50 6,417

1-0 Productivity Adjustment for Labor Not From Contractors

Regular Forces at 15% 341 11.82 4031 4,031

Total Direct Cost 106,889 30,909 1,051 138,849

Figure 205-6 gives the same eight-inch piping, using a PC program, Questimate (see Section 206). This figure uses First Quarter 1993 pricing.

A/C Description

Material Labor Sub-

con- tracts Total Quantity Unit Cost Cost Unit Mhs Man-

hours Rate Cost 306 Piping System Testing

Pipe Testing, Each 1 171 171 12.00 2,052 2,052

307 Prefab Pipe Rework

Repair & Adj Prefab Pipe, Each 1 126 12.00 1,512 1,512 311 CS Field Mat’l

Elbow, 8-inch, Std Wt, Each 30 39.80 1,194 1,194

Pipe, 8-inch Std, Feet 1,008 10.04 10,120 10,120

Tee, 8-inch, Std Wt, Each 6 59.52 357 357

Block Valve, 8-inch 150 Lb, Each 1 1,560.00 1,560 1,560

Flange, 8-inch 150 Lb, Each 16 35.56 569 569

Nipple, 8-inch, Each 1 20.00 20 20

312 CS Field Shop Fabrication

Pipe & Fittings, Feet 510 1.41 719 12.00 8,628 8,628 313 CS Remote Shop Mat’l

Elbow, 8-inch, Std Wt, Each 65 39.80 2,587 2,587

Pipe, 8-inch Std, Feet 628 10.04 6,305 6,305

Reducer, 8-inch, Std Wt, Each 4 19.75 79 79

Tee, 8-inch, Std Wt, Each 15 59.52 893 893

Flange, 8-inch, Std Wt, Each 34 35.55 1,209 1,209

314 CS Remote Shop Fabrication

Pipe, 8-inch Std, Lbs 23,091 0.80 18,473 18,473

315 CS Valves, Flanged

Ball Valve, 8-inch 150 Lb, Each 6 1,559.67 9,358 9,358 Check Valve, 8-inch 150 Lb, Each 3 862.00 2,586 2,586 Gate Valve, 8-inch 150 Lb, Each 13 840.00 10,920 10,920 317 CS Pipe Erection

Hot Tap, Each 1 69.20 69 12.00 828 828

Bolt up Connections, Each 47 4.20 197 12.00 2,364 2,364 Erect Shop Fab Pipe, Feet 1,138 1.14 1297 12.00 15,564 15,564 Erect Straight Run Pipe, Feet 498 0.67 334 12.00 4,008 4,008

Erect Valve, Each 22 5.60 123 12.00 1,476 1,476

Welding, Each 120 7.30 876 12.00 10,512 10,512

366 Pipe Hangers, Shoes, Etc.

Erect Prefab Pipe Supp., Each 83 60.24 5,000 6.35 527 12.00 6,324 11,324

Freight on Material, at 5% 3,562 3,562

Takeoff Allowance

(Outside Questimate), At 5% 82 3,740 222 12.00 2,664 6,404

When comparing estimates, note the following:

The sequence of items in each estimate follows the code of accounts for each method (chapter sequence, in Richardson).

Figures 205-5 and 205-6 show a fittings count and pricing while Figure 205-4 has the fitting prices buried in the unit cost for pipe. For hot tap, Figure 205-4 includes only the labor to make the tap, places equipment rental in the indirect costs (not shown), and presumably buries the cost to provide and attach the piping stub and valve in the piping material and labor costs. Figure 205-5 shows the subcontract cost for making the hot tap, but again assumes that the material and labor for the stub are elsewhere. Figure 205-6 has all the material and labor costs, but not the equipment rental.

There is considerable variation in the unit pricing of material and unit labor hours for individual items, although the bottom line cost is similar. Figure 205-4 does not show the number of fittings. We selected quantities for Figures 205-5 and 205-6 to make the grand totals similar.

Example of a Semi- Detailed Estimate

Figure 205-7 shows a semi-detailed estimate for the same eight-inch piping. We took off the total quantity of eight-inch pipe and added a generous quantity takeoff allowance.

A/C Description

Material Labor Sub-

contracts Total Quantity Unit Cost Cost Unit Mhs Man-

hours Rate Cost Piping take off from plot plan

8-inch piping, feet 1,500 Takeoff allowance at 15% 225 Total length 1,725 Diameter-inch-feet 13,800

Data1 from Section 411 13,800 5.19 71,622 0.17 2,346 12.00 28,152 99,774

Index to 1Q93 2 2,090 2,090

Total Direct Cost 73,712 28,152 _101,864

1 _{EDMI = 850, with current labor rate} 2 _{Section 301 (incremental cost)}

For this illustration, we

assumed that the quantity takeoff from a plot plan is 1500 feet added a 15 percent takeoff allowance

obtained a total of 1725 feet (similar to Figures 205-4 through 205-6 with their five percent quantity takeoff allowances)

converted the total to diameter-inch-feet by multiplying by the diameter of the pipe

estimated material costs and labor hours using factors for offplot piping (see Section 411) and adjusted them using cost indexes (see Section 301) to the first quarter of 1993

Summary The total cost in Figure 205-7 is significantly lower than in Figures 205-4 to 205-6 because that estimate allows for fewer valves.

The data in Section 411 is based on a project with 0.2 large-bore valves per 100 feet of pipe, which translates to 3–4 valves for the quantity of pipe in Figure 205-7. Figures 205-4 through 205-6 each show 23 valves. Therefore, based on the valve prices in Figures 205-4 to 205-6, the additional 19–20 valves easily account for the bottom-line differential of $33,000–37,000.