I first wrote about the declining quality of bid documents for ELECTRICAL CONTRACTOR’s April 2013 issue. Nine years later, the trend of electrical engineers providing less information on bid documents continues.
When I started estimating in the early 1980s, the bid documents were complete. The specifications were clear and easy to understand. The plans were fully engineered with only an occasional mistake. That is no longer the case. The following are what I miss from the bid documents I worked on in the past. Please note that these examples are from “theoretically” fully engineered documents for hard bidding.
Matching ceiling types
Yes, fixture specifications used to include the ceiling types in the catalog numbers. I was told that they stopped this in the Los Angeles area because of the many different types of suspended ceilings used in the high-rise buildings. If the engineer specified the wrong fixture, we submitted a change order because the proper fixture almost always costs more. The engineers did not like that.
Voltage drop calculations
During my first few years as an estimator, I never had to worry about voltage drop. I was a bit panicked the first time I saw a specification that made the contractor responsible for voltage drop calculations on branch wire. Fortunately, my boss told me not to worry about it, as the projects we were bidding were on the smaller side. Later in my career, the specifications made the task easier by requiring branch wire to be upsized after a certain footage. Still, it was another task I had to finish to produce an accurate estimate.
The next aspect to disappear from the bid documents was conduit and wire sizing for branch conduit on the floor and roof plans. The first to go were mechanical and HVAC loads. For a while, those requirements were moved to a table or two on other plan sheets. However, the sizing for mechanical and HVAC loads on recent projects has started to disappear altogether. Therefore, I must refer to the schedules on the mechanical plans to get the load requirements and calculate the wire sizes myself.
Another related problem is that most of the projects I estimate no longer have any of the branch conduit and wire sized. Most often, the symbol list indicates that a line with no hash marks is two No. 12 and one No. 12 ground.
This is not true in most cases now, as there are often many conduits without hashmarks that need more or larger wires. My solution is to go to the panel schedules first to identify any circuits needing more than two No. 12 and one No. 12 ground, and measure those runs first. After these upsized circuits are measured, the remainder are mostly two No. 12 and one No. 12 ground. The exceptions usually have to do with multiple circuits in one conduit and 3-way switching.
The invisible loads
A more recent development is electrical plans that do not show the locations of everything I need to complete the estimate. This is particularly true for industrial work, but it also occurs on commercial projects.
I could send formal requests for information to the general contractor. However, I expect the answers would be the same thing I am doing anyway, which is going through the other trades’ drawing sets looking for answers. I usually find what I am looking for on the architectural, civil, plumbing or mechanical drawings. On one commercial project, no HVAC was shown on the electrical drawings. There were a few circuits indicated in the panel schedules, but even that was incomplete. I had to study the mechanical drawings for the location and electrical characteristics of each unit.
The practice of not showing all the electrical loads on the electrical drawings concerns me, as it makes the load calculations for the project inaccurate. In this example, there were many large HVAC loads not accounted for. This could affect the load calculations from the main switchgear all the way down to the panelboards. If this happens to you, make sure to qualify in the proposal that you are not responsible for any costs related to the additional loads.
The scale of it all
I have written about inaccurate scales before. I mention it again now because the problem is getting worse. For your own protection, assume the scale on every plan sheet is wrong. Use the custom scale feature on electronic scalers or the calibrate routine for on-screen takeoff programs on each plan sheet. Don’t ever assume they are all correct just because one plan sheet is correct.
Be careful, estimators. Although the bid documents are less complete than ever, you are still responsible for a full estimate.Header image by Shutterstock / Ranjith Ravindran.
About The Author
CARR has been in the electrical construction business since 1971. He started Carr Consulting Services—which provides electrical estimating and educational services—in 1994. Contact him at 805.523.1575 or [email protected], and read his blog at electricalestimator.wordpress.com.