You can arrive at man-hours by using the following formula. 49 Man-hours are one of the most misunderstood areas of the estimate, but they are simple once you understand it. Exposed work will take an additional 20% so my suggestion for exposed work would be 100%.
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.
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. The same factors should be considered for multiple story buildings. My suggested man-hours would increase to 85% for installations over 10 feet and to 110% for installations of 16 to 20 feet.
All of these factors increase the man-hours. Take into consideration such things as ceiling heights and the floors of a building. This is for standard 1 and 2 story work with 9’ ceilings. Most companies that I have estimated for can install work at about 80% of the book’s manhours. 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. 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. Man-hours out of a book are just a great starting point. A labor unit is a benchmark used by a company or estimator to determine the labor value of an installation. It is used in written “estimates” for estimation of the total amount of uninterrupted labor required to perform a task. 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. Therefore, it is important to understand the use of man-hours. This is based on calculating the installation time of each item down to the manhour. Understanding Man-Hours Every proper electrical estimate must include the time that it will take to install all of the material.