=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.