Do You Trust The Drawings?

One of the recurring themes of my writing has been the continuing decline in the quality of electrical bid documents. Let’s put it this way: the bidding documents, plans and specifications have become a black hole, sucking up estimating hours like never before. Before I get into specifics, let me clarify that I am referring to plans released for bidding on both private and public projects.

What irritated me enough to inspire another article about bad documents? Recently, I worked on a large low-voltage 
project that appeared to be very well designed. The floor plans seemed to be well-engineered and indicated an extensive amount of branch conduit with only a few labeling mistakes. However, being a thorough estimator, I reviewed the riser diagrams. Usually on these types of projects, the risers are only typical representations of the devices and wiring methods. Yet, while reviewing this set of riser drawings, I noticed a wire type I had not seen on any of the floor plans. Sure enough, after some research and a few phone calls, I confirmed that this project required the wire type. If I had not carefully reviewed the riser diagrams, I would have missed several thousand feet of conduit and wire.

You may think that, because the wire in question was not shown on the floor plans, you would not have to include it in the estimate. In most cases, you would be wrong. Almost every specification I have read states something like “any work shown in one location on the plans will be considered to be shown in all locations.” This means, if the wire is on the riser diagrams, you must include it in your estimate.

Another problem with drawings I see more frequently these days is inaccurate scales. Not only are the stated scales incorrect, but the graphic scales are also incorrect. Most of the time, they are inaccurate in a way that you will come up short in your measurements. Occasionally, they are imprecise in a way where you will never win the bid because you overestimate your measurements. Just yesterday, I worked on an industrial project with graphical scales. I set my scale according to the graphic and started measuring. Right away, something seemed off; a feeder running across a small control building measured more than 200 feet. I went to the architectural drawings and found that the building was only 68 feet long.

To protect yourself, you must calibrate the scale on every page of every project you estimate. For those unfamiliar with this process, it works as follows: Find a written dimension for the page you are working on, usually on an architectural plan. If you have a mechanical scaler, upgrade to an electronic model. Once you have the dimension, set a custom scale on your electronic scaler. Check your instructions if you don’t know how.

The process usually includes measuring a dimension and typing the distance into the scaler. If you are using an on-screen takeoff program, use the “calibrate” command to set the scale. This usually consists of pointing to the beginning and end of your measurement and typing in the actual length of that measurement.

Let’s talk some legalese. In 1918, the U.S. Supreme Court recognized the legal doctrine of implied fitness of design warranty (United States v. Spearin, 248 U.S. 132). The doctrine provides that a contractor, bound to build according to plans and specifications prepared by an owner, is not responsible for the consequences of defects in the plans and specifications.

Recently, the U.S. Court of Appeals for the Fifth Circuit ruled that a contractor’s immunity created by the doctrine of implied fitness of design warranty, as codified in Louisiana law, can include immunity for failure to warn an owner of defects or errors in the owner’s design (LaShip LLC v. Hayward Baker Inc.). Therefore, a contractor may not be responsible for damages resulting from its implementation of an owner’s design, even if the contractor could have discovered and reported the defects in the documents to the owner.

Since you may not want to engage in a legal battle, you can protect yourself from poor and incomplete engineering by writing a thorough proposal. Exclude work that is not shown on the electrical plans and exclude dangerous phrases in the specifications. The scariest one I have seen recently goes something like: “Review the specifications and drawings of all other trades for electrical work and include any electrical work you find in your proposal.” 

Please, give me a break.

For more on the Spearin doctrine, see “A New Norm for Defective Drawings” by Gerard Ittig in the July 2017 issue of 
Electrical Contractor.

About the Author

Stephen Carr

Estimating Columnist

Stephen 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, and...

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