The Art of Estimating Materials and Labor
Posted By Houston Decorator on January 14, 2010
The most correct method of estimating is by taking out accurate quantities of materials and items of all kinds and pricing them as the figures are obtained, and then adding the cost of labor to each item. This method, because of its entailing so much labor, should be adopted only when it is intended to carry out the work and when a tender is sent in or submitted for work about to be gone on with.
It is very laborious, and necessitates great skill and a thorough knowledge of building construction, and particularly of the work to be tendered for, so that the subject is somewhat difficult for young hands to deal with. In this method a full set of drawings of the work, copious specifications, and appropriate measuring wheels are necessary, so that the estimator can take the dimensions from one and quality of material and character of work from the other.
The cost of the various descriptions of material and workmanship is then priced in accordance with the current rates obtained in the locality where the work is to be carried out. In fact, it is the only method a young contractor should use when commencing business. After years of experience and observation as a builder and contractor, cubing, or one or other of the quick methods, may be made use of under certain conditions, where the contractor knows what he is about.
Sage advice, however, is to stick to the old and reliable method of estimating by items and the use of applicable private label tape measures or even tanking gauge tapes. It takes time, but the time and labor are well invested. It is but just to say that these rules and methods can be found in many works, but it has been thought expedient to reproduce them here, so that the student may have them at hand when making use of this work for study or for practical estimating.
The rules and problems are selected chiefly from educational works, and the tables have been prepared by competent authorities, and have been examined and corrected, where necessary, and made suitable to the work in hand. Previously, it has been shown at length how a detailed estimate of the cost of any ordinary building may be ascertained; and while the process is somewhat lengthy and tiresome, it is decidedly the better method for the younger estimator to follow.
The longhand method has many advantages over all the others, besides being the best of practice for the figurer and will make him familiar with all details pertaining to building and construction. A few remarks on the much-lauded cubing system may not be out of place at this point, as it is the best known method after the “detailed” and the most usually adopted for hurried estimates, because of its general convenience. In this case the dimensions are best taken by measuring the length and breadth from out to out of walls and the height from half foundation to half way up the roof.
The cubic contents then obtained are multiplied by the price per foot of some building of similar style whose cost per cubic foot is known. The cubing method is open to many objections, for the lumping together of voids and solids is not by any means a scientific process, but more of one that requires measuring wheels and measuring tape. The same class of buildings may be divided into many rooms with many shapes and a great number of doors and windows.
Meanwhile the one being estimated upon may have much larger rooms and fewer of them, which would, of course, make quite a difference in the total cost. This method requires a large experience and a nicety in pricing which the estimator cannot always possess. The description and quality of materials and workmanship, too, are seldom the same; neither are the conditions of contract and these variations are frequently overlooked when a certain rate per cubic foot is assumed.
Allison Ryan is a freelance writer from San Diego, CA. She specializes in home improvement and construction; from the best measuring wheels to what private label tape measures to use. For measuring tape and world class tools from 1876, check out http://www.ustape.com/.
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