The other day, I saw an online discussion about using the labor units that come with computer estimating systems. The question was whether you should use the labor units as is. The simple answer is “maybe.” The complex answer is also “maybe.”


The bottom line is that the application of labor units can be very complex. Let’s start with where they come from. The National Electrical Contractors Association (NECA) first published the Manual of Labor Units (MLU) in 1923. A task force of member contractors from a variety of markets and contractor sizes revises it every other year. You should definitely read the instructions in the front of the manual and each section before using the labor units. 


There are three columns of labor units: normal, difficult and very difficult. It is important to understand that the “normal” column is only to be used for simple construction, including items such as new construction with new materials, three stories and fewer, inside your normal geographical area of work, within standard hours, etc. A complete list of conditions and a labor-factor score sheet are in the manual. Any deviation from normal conditions is a reason to adjust your labor units. Most often, you will adjust them upward.


It’s complex


Here’s a real-life example. I was estimating a 1-million-square-foot hanger for McDonnell Douglas. The scope included the installation of 14,400 feet of 4-foot rigid conduit above the truss. The conduit was to be installed in four parallel runs. Since the truss height varied from 50–80 feet above the floor, zoom booms would be required to facilitate the installation. However, digging into the documents, we discovered the general contractor would suspend a work platform from the bridge crane rails. The platform would change positions every two weeks, eventually covering the entire building. This meant we could make our installations using an 8-foot ladder.


As you can imagine, coming up with a labor unit for this installation was complicated. Right up front, we have one of the few reasons to factor labor down: parallel conduits. Four parallel conduits could have a labor deduction of around 20 percent. Next, since we are working on the platform, we do not need to factor up for the height. However, we need to consider how much time it takes to access the platform. In this case, there was only one construction elevator, so we had to anticipate delays. In addition, since the building was so big, it took a long time to get from our yard to the work locations in the building. Coming up with the labor factor for time spent getting men and materials up to the platform and then back down was difficult, because this kind of situation was not in any labor manual I had ever seen. We had to make a judgment based on experience and a little guesswork.


Let’s get back to the original question about the labor units that come with estimating systems. These systems often come with several columns of labor units. Three of them are usually similar to the columns in the MLU. A fourth column—competitive—is often included and is less than the MLU normal column. Be careful using this column because it is meant for contractors working in areas and on projects where they get superior production from their crews. If you are at such a company, these competitive units can be used based on your company’s experience.


Release the hounds


During my first 10 years as an estimator, I was fortunate to have worked at several companies that practiced tracking the labor used on a project by categories, such as fixtures, rough-in and finish. I recommend keeping the number of basic categories to around a dozen, with a few more for special systems on a project. 


This accomplishes two things. First, it is a project management tool that allows you to see if you are using up the estimated labor for a category too quickly, so you have a chance to investigate and make corrections before it is too late. Second, when the project is done, you can analyze the differences between the estimated labor and the actual labor. Having this kind of historical data is a great tool for future estimates.


So the answer to the original question is yes, you can use the labor units that come with an estimating system if a project falls under the normal conditions that the MLU describes. If the project is not “normal,” you must adjust your labor units accordingly.