Key Notes: Carefully read notes on plan sheets

Shutterstock / Stokkete
Shutterstock / Stokkete
Published On
Nov 15, 2021

When I first started estimating, notes on a plan sheet were very rare. Now, it is the opposite. Almost all plan sheets have notes, and many have dozens. You might say today’s projects are more complex than they were 40 years ago, so they need more notes. I disagree. Projects in the 1980s had all of the same systems that are in today’s, including fire alarm, security, communications and data. In many instances, the old systems were more complex to estimate because the wiring was analog, which often required more wire compared to digital systems.

For instance, a fire alarm branch run may have required dozens of No. 14 wires going to the devices instead of a single twisted pair of No. 18 wires looping between the devices. Telephone risers in a small office building were hundreds of wires, but now they can be a single fiber optic cable. I believe that in many cases, notes are being used instead of actually drawing the scope on the plan sheets.

Notes can convey much information, such as elevations and specifications for materials and scope. The latter is the most dangerous because a short note, easily missed, can require thousands of dollars worth of material and labor.

General notes

General notes that affect the entire project will usually be found on one of the first plan sheets. It is important to read these notes carefully before you start the takeoff. For instance, instead of using a special symbol, a note, which only appears just this once, may require tamper-proof receptacles in all public areas. In the last few years, I have seen a significant increase in general notes that require scope not indicated elsewhere in the electrical documents, including the plans and specifications.

I have seen notes that require simple items such as a delivery doorbell system, and those requiring large, complex items such as a 2,000-kilovolt-ampere UPS system. These notes can be extensive while specifying the parts required, how the system is to be installed and who is qualified to install it.

I also often see general notes that describe how the branch wiring is to be designed, including normal systems, emergency systems, voltage-drop calculations and harmonic feedback restrictions. An example would be, “Find an existing emergency circuit and connect it to all emergency fixtures and exit lights” or “The wire size for all 120V circuits over 75 feet must be increased to No. 10 AWG.”

General notes on other plans

Other than the first, notes on plans sheets come in several varieties. Most often, there are general notes that apply to the entire plan sheet. They can be specifications, such as, “All conduit on this page shall be EMT.” They can require additional electrical materials not shown on the plan, such as requiring seal-off fittings everywhere a conduit penetrates the wall of a cooler or freezer. They can also be scope requirements such as, “Demolition shall be the responsibility of the electrical contractor.”

General notes on a plan can also attempt to excuse the designer from providing a complete and accurate design. Consider this note: “Existing conditions shown are based on as-built drawings provided by the owner. Adjust for actual field conditions at no additional cost to the owner.” Here is another example: “Branch circuit wiring is shown as a guide. Exact quantities of conduits and conductors are not indicated. The contractor shall provide branch circuit wiring as required for a complete and operable system.”

Another type of note on plan sheets is the key, specific or plan note. Usually, you will see a number in a box, circle or oval that refers to a list of notes on the plan sheet. For instance, 9 in a circle points to a junction box on the plans. When you refer to Note 9 in the list, it tells you to furnish a junction box, circuit and connect to the architectural lighting.

Sometimes, notes conflict with each other. I recently saw a note that specified all demolition to be done by the electrical contractor. The very next note said that the electrical contractor is only responsible for disconnecting and making safe so the general contractor can do the demolition. This kind of conflict requires coordination with the contractors to whom you are bidding.

Plan sheets with many notes have become the standard on projects ranging from a small strip mall store to the most complex industrial projects. As an estimator, you must read, understand and implement the requirements of every note on every plan sheet. If you gloss over or ignore notes, it can be very costly. Per my “if it’s not marked off, you missed it” philosophy, I recommend marking off the notes only after you have completely complied with them.

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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