58. Plans. - If work of importance is being considered, a contractor should always insist upon having a complete set of plans, a carefully prepared set of specifications, and a written contract, all so drawn as to insure against the possibility of a misunderstanding.

59. Location. - The contractor should be familiar with the location of the house and be thoroughly posted concerning the facilities for transportation and for obtaining material and help. He should know how far from the excavation the earth has to be carried and should have reliable information about the nature of the subsoil and the possibility of ledges and springs which might cause difficulty in making a dry cellar.

60. Method. - In writing the matter for this chapter, the plans of a house and its accompanying stock list and estimate have been purposely omitted, as it will be far better that the students or teacher should select a small accessible building, make a set of plans of it from actual measurements, and use these as the basis from which the estimates and the stock lists of the class should be made. In this case, the building can be used for the purpose of study and demonstration, thus giving the student the benefit of comparing his work with actual results.

By the approximation method1 of estimating, the estimator works upon the basis that the use of a certain quantity of a certain sized material will accomplish a known result; for instance, instead of counting the exact number of studs necessary to stud the wall of one side of the house, then of another, he measures the entire distance to be covered by all of the walls and partitions, and allows one stud to each foot, with an additional one for each angle and opening. Instead of figuring that a man can set a certain number of studs in a given time, the cost is found by figuring that it will cost a certain amount to set a thousand feet (board measure) of studs.

The estimate based upon the approximation method should be first worked out, followed by the stock bill from which the actual work would be done if the building was to be built. If the building which is being studied was built by contract, and copies of the contract and of the original stock bill could be secured, they would be of great value in criticizing the results of the work of the class.

A contracting carpenter may follow the safe method of getting estimates upon the different parts of the building which must be done by other workmen, then adding his own estimate; to this total are added the amounts for incidentals and profit, the sum of which is his bid for the contract. If he is awarded the contract, he treats the bid from each sub-contractor as a maximum, and tries to find a man who will do the work for a lower price. This method usually results in fewer contracts, but there is less risk than if the contractor depended upon his own figures entirely. It is impracticable to give here prices of labor and material, as they vary so that no list can be devised which will suit all localities and times; therefore we shall, in most cases, discuss only the time necessary for doing the work under average conditions, and the methods of estimating the materials, leaving the student to obtain the local prices. All estimates are based upon a day's labor of nine hours.

1The term "Approximation Method," as used in this book, has no relation to the "Preliminary Approximation Method," which is based upon the cubical contents of a building and is principally used by architects in arriving at the approximate cost of a contemplated building.

The contractor should not try to save too much time in estimating, but should aim at accuracy and safety, since this is as important as it is that the work is done well and economically.

Note. - In all estimates given, the student should not forget that they are based upon the actual cost, and that, for the estimate to be submitted, the profit is to be added to the total cost.

Whether he gets the job or not, the young contractor should keep a systematic and permanent record of all his estimates, the cost of material and labor, and any information he may think valuable; if he does the work himself, he should check his estimates when the actual results are known. This record will be found of great value in making succeeding estimates. A pocket size loose-leaf binder is a great convenience for the valuable data which is continually presenting itself.

In order to estimate successfully, there should be a schedule containing the items to be estimated. These should be considered one at a time to ascertain the necessary dimensions and quantities, after which similar items of the same price should be gathered together and the cost of the total quantity estimated as one item. The totals of these different items should be summarized, and their total ascertained; to this should be added from 5 per cent to 25 per cent for incidentals, use of equipment, etc., and the same percentages should govern the amount to be added for profit. The grand total should be the amount of the bid.

61. Excavations. - Under the head of excavations, unless otherwise specified, should be included those for the cellar, piers under the partitions, porches, cisterns, cesspools, vaults, and trenches for the water and sanitary system of the house.

The excavated earth should be carried far enough away so that it will not interfere with the workmen, but if it is to be used for filling and grading around the house, work which is usually in the contract for the excavation, it should be carried as little distance as possible.

For a day's work, two men should excavate from 10 to 12 cubic yards of sand, gravel, or moderately soft clay, and carry it 60 feet in a wheelbarrow. Two men and the driver, with a horse and cart, should pick, throw out, and carry the same distance from 16 to 20 cubic yards of the same sort.

Filling in and grading around the house usually costs about a fourth as much as the excavating.