The Golden State: Where & How to Live, Secure, Visit, Enjoy and Thrive in California
Plumbing Heating And Piping
Explanation of Methods
1.1. General Discussion
The use of a bid summary is not a new concept in estimating. It has been found, by years of use in many fields, to be the only practical tool available to keep the estimator aimed at his ultimate goal. The bid summary will be used in this book for the same purpose. It is essential that the estimator follow this summary which will be fully explained at the appropriate place in the text.
The efficiency-factor method of setting labor requirements used in this book necessitates an explanation of its development and a thorough understanding of its meaning by the estimator. It is certainly not complicated, but it must be understood in order to avoid errors caused by misuse or misconception.
First, we consider that since we are estimating the amount of labor required to install a certain number of pieces of material, we must begin with an accurate take-off of material. The fitting take-off is of utmost importance. If the material list is a guess, the labor established by this method will be based on that guess. Slipshod take-off of material will produce poorly evaluated labor requirements.
1.2. The Efficiency Factor
The efficiency factor E used throughout the tables given in this book is actually an evaluation of the difficulty of installation of the particular system involved. Its selection is based on the estimator's best judgment of the conditions which will prevail at the time the system is installed. The estimator should evaluate such conditions as weather, area labor, ability of available supervisory staff, and the probable working conditions in the area through which the system will be run. He should determine the efficiency factor E which he will use based on this evaluation. If he considers conditions to be average, he should set E equal to 1.0. If he believes the work, for some good reason, will be less costly than average, he should use E less than 1.0 by a variation which he considers proper. The same holds true should he consider the job more difficult than average; he should then set E equal to a figure larger than 1.0 by an amount which he considers appropriate.
The determination or evaluation of the efficiency factor E is of utmost importance to the final value of the estimate. In order to assist the estimator in this evaluation, the following is a list of items which should be considered concerning the project and conditions surrounding its development or construction:
1. The general economy of the area, the economic trend, and the construction volume available in the area
2. Labor availability and probable training
3. Supervision, availability, training, and ability
