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sequence in which the work is physically performed, and the trade symbol prefixed to the numeral. If "M" represents masonry, "M.1" might be excavation, "M.2" shoring, "M.3" concrete foundation, "M.4" brick-work. It is sometimes advisable to break up a principal feature into the subfeatures composing it. A letter designating the subfeature is affixed to the feature symbol. If "M.I" is the excavation symbol, "M.1.E" would be earth excavation, and "M.1.R" rock excavation. When a particular contract includes features of work applying only to it, special symbols are established for use during the life of the contract.

Features of work should, of course, always be broken up to whatever extent is necessary to furnish data having a productive value greater than the cost of obtaining the additional information.

The Cost Ledger

The cost ledger consists of loose-leaf sheets.

The ledger sheet used provides columns for recording data in connection with the actual cost and with the estimated cost. Those dealing with the actual cost, beginning at the left of the sheet, are successively as follows:

1. Date column.

2. Column for the reference number of the purchase register
sheet.

3. A column for description or quantities of material used.
4. The amounts of contracts let and extra orders issued to

subcontractors.

5. The amount of applications received from subcontractors for work done by them.

6. The cost of materials.

7. Wages of mechanics.

8. Wages of helpers, etc.

9. Total of columns 5, 6, 7, and 8.

The column for description of material (column 3) is subdivided into smaller columns for recording quantities used on different classes of bulk material, such as brick, sand, cement, etc. Each column is headed with the name of the material and the unit price paid for it. These smaller columns can also be used for an analysis of the main items composing the cost of supplies other than bulk material, this analysis being shown either in money values or quantities.

The columns dealing with the estimated cost are in successive order:

1. Column for the reference number of the extra order.
2. The estimated cost of work to be let to subcontractors.

3. The estimated cost of material.

4. The estimated cost of labor.

A sheet is assigned to each feature of work for which there is a cost symbol. The symbol is inserted in a blank space provided for the "Subdivision" and a description of the work included in the subdivision is noted in the upper left-hand corner. Each sheet is a record of estimated and actual cost. The four columns at the right contain the record of estimated cost and the remaining columns show the details of the actual cost.

Estimated Costs

Postings to the columns marked "Estimate and Change Orders" are taken from the working estimate and from change order cards. These cards are the detail trade classification of work included in extra orders issued by the architect and are prepared by the employee in charge of changes in plans and specifications.

The proper amount given in the working estimate as the estimated cost of each subdivision is posted in the three columns marked "Contracts," "Material," and "Labor" ("Contracts"

means work let to subcontractors). When all items appearing in the working estimate have been posted to the proper subdivisions, the total of these three columns on all ledger sheets should equal the total of the working estimate. The total should also be the remainder obtained by deducting the original estimated profit from the amount of the original contract, as recorded in the Owner's account (Form 22, page 161) kept by the accounting department.

The amounts appearing on change order cards are posted to the subdivisions indicated by them: The total of the three columns on all ledger sheets should then equal the remainder, obtained by deducting the total of the profit column from the total of contract and extras as shown on Form 22.

These three columns of the cost ledger sheet are the analysis of the estimated cost of work by features of work and the basis for controlling the actual cost of performance. The number of the change or extra order is indicated in the column marked "Change."

A memorandum record showing the amount of the original contract with the owner and of each extra order, together with the estimated profit thereon, should be kept by the cost department as a control of the figures in these three columns.

ACTUAL COST. Actual cost of performance is recorded in the remaining columns on this sheet. The postings are made from the purchase register (Form 18) and can be the total amount charged to a particular subdivision on any purchase register sheet, except when the character of any charges posted will act as a control of the number of units of work performed, such as brick, etc. The details of other items forming a substantial portion of the charge to be posted to the subdivision can be entered whenever any advantage results. The first two columns at the left are references only as to the date and number of the purchase register sheet. The subdivisions of the panel headed "Description" into smaller columns is for record

ing the quantities of different classes of material used on each subdivision, such as brick, sand, cement, broken stone, etc. The class of material is indicated at the top of each column and the quantity used on the line to which the cost of the material is posted.

"Contracts Let" and "Requisitions" refer to contracts sublet. The amount of the subcontract or extra order is entered under "Contracts Let." The value of work performed by the subcontractor is posted from the purchase register to the Requisitions column. The total money value of all charges, except those covering payrolls and subcontract work, is posted from the purchase register sheets to the Material column. The sums spent for weekly payrolls are divided and are entered under Mechanics or Helpers. "Total" is the sum of the Requisitions, the Material, and Payroll columns. The sum of the "Total" cost of all features of the work must at all times equal the total of all purchase register sheets and be in agreement with the actual cost of the job appearing on the books of the accounting department. The amounts of contracts let do not enter into actual cost until work is performed and applications from the subcontractors charged to construction cost on the purchase register.

Cost Elements

The chief elements entering into the cost of work are:

1. Payrolls of mechanics and laborers.

2. Cost of material.

3. Service charges, including hauling, surveys, tests, insurance, commissary operation, stable operation, etc.

4. Cost of work let to subcontractors.

5. Job overhead, representing the cost of supervision, maintenance of a field office, etc.

6. Charges for construction equipment.

7. Expenses of contractor's office which are not overhead

expenses.

CHAPTER XXII

ANALYZING COSTS

Importance of Labor Costs

The most important element in construction cost-keeping is the one dealing with labor costs. Their relation to work in hand and work in prospect should be clearly understood.

When preparing a bid for a prospective contract, the contractor examines the plans and specifications to ascertain the number of units of different work required to be done and then values these units. To the sum of these values, he adds his profit, and the total is the basis of the contract price between himself and the owner. It follows that values placed by the contractor on the units of work really represent the selling prices of these units of work to the owner.

If the contractor finds that a building requires one million brick which he values at $40 per M, he is in effect saying he will sell the owner one million brick laid in the wall for $40,000. This $40,000 includes the wages of brick-layers and laborers, the sum paid the manufacturer for the brick, and his disbursements for sand, cement, hauling, and other incidentals.

When the contractor decides upon a value of $40 per M, he has in mind a certain cost for brick, for sand, for cement, for labor, etc. The city in which the building is to be constructed and the location of its site materially affect the amount that must be paid for freight and for hauling. The law of supply and demand has a decided bearing upon the amount the manufacturer demands for his brick, inclusive of freight and hauling charges. Proper valuation of brick for estimate purposes requires that dealers be requested to quote prices for

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