National Electrical Code

Grounding Requirements for Floating Buildings

Oct. 16, 2018

If a building is floating, how do you connect it to the earth?

Part III of Art. 553 of the 2017 National Electrical Code (NEC) provides the requirements for grounding buildings that float. Part III begins by requiring that all electrical and non-electrical parts be grounded (ground terminal connection) via connection to the grounding bus in the building panelboard [Sec. 553.8(A)].

Article 100 defines “ground” as “The earth.” If the building is floating, how do you connect it to the earth? You connect the grounding terminal in the service equipment through an insulated grounding electrode conductor to a grounding electrode on shore [Sec. 553.8(D)]. Notice, there’s no mention of using the water as ground; not for bonding the equipment and not for grounding the floating building.

The grounded circuit conductor (neutral) must be connected to the equipment grounding terminal in the service equipment. That is the only connection it can have to equipment grounding conductors (EGCs). And it must be an insulated conductor [Sec. 553.9]. Ensure the neutral conductor terminals in panelboards and appliances are insulated from the enclosures.

Connect non-current-carrying metal parts (e.g., metal piping, electrical enclosures, metal parts contacting the water) to the grounding bus [Sec. 553.10(A) and Sec. 553.11]].

About the Author

Mark Lamendola

Mark is an expert in maintenance management, having racked up an impressive track record during his time working in the field. He also has extensive knowledge of, and practical expertise with, the National Electrical Code (NEC). Through his consulting business, he provides articles and training materials on electrical topics, specializing in making difficult subjects easy to understand and focusing on the practical aspects of electrical work.

Prior to starting his own business, Mark served as the Technical Editor on EC&M for six years, worked three years in nuclear maintenance, six years as a contract project engineer/project manager, three years as a systems engineer, and three years in plant maintenance management.

Mark earned an AAS degree from Rock Valley College, a BSEET from Columbia Pacific University, and an MBA from Lake Erie College. He’s also completed several related certifications over the years and even was formerly licensed as a Master Electrician. He is a Senior Member of the IEEE and past Chairman of the Kansas City Chapters of both the IEEE and the IEEE Computer Society. Mark also served as the program director for, a board member of, and webmaster of, the Midwest Chapter of the 7x24 Exchange. He has also held memberships with the following organizations: NETA, NFPA, International Association of Webmasters, and Institute of Certified Professional Managers.