Understanding Man-Hours Every proper electrical estimate must include the time that it will take to install all of the material. This is based on calculating the installation time of each item down to the manhour. Therefore, it is important to understand the use of man-hours. So, what is a manhour? The definition of a Man-Hour is: A man-hour, Labor Unit or Person Hour is the amount of work performed by an average worker in one hour. It is used in written “estimates” for estimation of the total amount of uninterrupted labor required to perform a task. A labor unit is a benchmark used by a company or estimator to determine the labor value of an installation. Notice the word benchmark. Man-hours out of a book are just a great starting point. A good estimator will include their own knowledge and working experience along with the level of difficulty that a certain phase of work will take. It would be impossible to relate all the influences that affect labor units, but you as the estimator must consider Job Difficulty, Installation difficulty, and at what percent of the given man-hours is your company able to perform the work. Most companies that I have estimated for can install work at about 80% of the book’s manhours. This is for standard 1 and 2 story work with 9’ ceilings. Take into consideration such things as ceiling heights and the floors of a building. All of these factors increase the man-hours. My suggested man-hours would increase to 85% for installations over 10 feet and to 110% for installations of 16 to 20 feet. The same factors should be considered for multiple story buildings. Examples of Multi Story building labor additions 1 to 2 floors +0% 3 to 4 floors +2% 5 to 6 floors +3% 7 to 8 floors +5% 9 to 10 floors +7% 10 to 15 floors +15% This does not include exposed work, block work or poured in place concrete. You may never get a block job by using this tip, but it is my experience that it will take at least double the man-hours to install work in block. I suggest 200% of book. Exposed work will take an additional 20% so my suggestion for exposed work would be 100%. 49 Man-hours are one of the most misunderstood areas of the estimate, but they are simple once you understand it. You can arrive at man-hours by using the following formula. Minutes to perform a task divided by (1 Hour or 60 Minutes) = man-hours. Example: 15minutes / 60 = .25 man-hours .25 man-hours x 60 = 15 minutes 1 man-hours = 1 Electrician working for 1 hour or 2 electricians working for 30 minutes. So, the amount of time it takes to install electrical materials is measured in man-hours. This makes calculating time when estimating more precise. It is manageable to estimate a project that will last a couple of weeks just by saying that it will take 1 day to do this function and 2 days to do that function, but when estimating projects longer in duration, then it becomes essential to revert back to man-hours. Each piece of material, no matter how big or how small, will have an associated man-hour. This is the time allotted to install the item. The following is a Labor Breakdown Conversion Chart: Labor Unit breakdown .05 Man Hour = 3 minutes .10 Man Hour = 6 minutes .15 Man Hour = 9 minutes .20 Man Hour = 12 minutes .25 Man Hour = 15 minutes .30 Man Hour = 18 minuets .35 Man Hour = 21 minutes .40 Man Hour = 24 minutes .45 Man Hour = 27 minuets .50 Man Hour = 30 minutes .55 Man Hour = 33 minutes .60 Man Hour = 36 minutes .65 Man Hour = 39 minutes .70 Man Hour – 42 minutes .75 Man Hour = 45 minutes 1.00 Man Hour = 1 hour 50 Every estimator should select a standard of man-hours, whether published or created from experience. NECA man-hours have been the benchmark of the electrical construction for as long as I can remember. Most all estimates are derived from using standardized manhours. Practical Man Hours As stated before, each item will have an associated man-hour. The process will begin by creating your material list, then placing a man hour by each item, then extending the math and total. Next, you would price each item, extend the math and total. The following is an example: Also, to have a complete estimate, you will also need to place a price by each item as shown in the following example: 51 As you can see this is a long and tiring process. I can’t tell you how many 20 page estimates that I have penciled in just like the examples above. Hour after exhausting hour of looking up man hours and pricing each line item. With an electrical estimating software like the Best Bid by 1CEES, this can be created in detail in seconds not hours. Simply by entering the QTY of 10 will produce a detailed list of material with pricing and man hours extended.
