=3. Important Factors.=—The prime considerations in making an estimate are accuracy and time. To these ends the estimator must systematize his efforts, and endeavor to do a maximum amount of work in a minimum amount of time. This, however, should not be done at the expense of accuracy, for accuracy is the most important factor and is only insured when the figures are carefully checked. The estimator, therefore, while avoiding too great refinements in calculation, should aim at correctness rather than at speed in doing the work. Very frequently do the effects of haste and inaccuracy in estimating the cost of a structure become evident when it is too late to remedy the errors, resulting sometimes in the financial ruin of the builder that trusts too implicitly in the estimator’s figures. A record should be kept of all estimates made, as this kind of information is most valuable and establishes a precedent on which to base subsequent estimates, as well as a check on the work at hand. PRINCIPLES OF ESTIMATING APPROXIMATE ESTIMATING =4.= In order to make a preliminary estimate, before the plans of a structure are drawn, but after the general dimensions of the proposed building have been determined, architects and builders sometimes employ a method of =approximate estimating=, by which the cost is figured at so much per cubic foot of the building, the rate varying according to its character and the finish required. The method is also considerably used by insurance companies in fixing the amount to be placed on a building. It should be borne in mind that this method gives the approximate cost only, and should never be used in figuring the contract price of a building. This estimate, however, may be used to advantage in checking the accurate estimate, with which it will frequently be found to agree remarkably well. TABLE I COST OF BUILDINGS PER CUBIC FOOT ==========================================+============= | Cost Class of Building | Cents per | Cubic Foot ------------------------------------------+------------- Small frame buildings, costing from $800 | to $1,500 | 10 to 12 Frame houses, 8 to 12 rooms, costing from | $1,500 to $10,000 | 12 to 15 Reinforced-concrete mill buildings | 10 to 14 Brick houses, 8 to 10 rooms | 15 to 18 Highly finished city dwellings, brick or | stone | 20 to 25 Schoolhouses, brick | 12 to 20 Churches, stone | 20 to 40 Office buildings, well finished | 35 to 50 Hospitals, libraries, and hotels | 35 to 50 ==========================================+=============