Please Design Safely

The very nature of design/build projects requires you to participate in the design process. You may even feel comfortable with assisting in this process. However, these types of projects come with increased responsibility.

With most design/build projects, the owner will ask you for your opinion. And, in some cases, the owner will ask you to either design or “value engineer” the fire alarm system. It is especially important in all design/build projects that you understand the owner’s fire protection goals before proceeding with your proposed design or value engineering.

When it comes to fire protection, never assume the owner will only want the minimum requirements dictated by the code. In addition, you should seek the input and approval of the local authority having jurisdiction (AHJ). He or she will provide valuable insight into the local code and jurisdiction’s requirements and let you know which manufacturers have the most reliable reputation in the jurisdiction. However, remember that, even with AHJ approval, you still have to meet the code requirements.

And also remember that so-called designing-by-walking-around does not equal design/build. You must fully and carefully document your design, and you must provide scaled design drawings.

You also may have the opportunity to influence the owner on which fire alarm system manufacturer to use. Choose wisely to ensure your choice will also make the new fire alarm system easier to install and more reliable to maintain.

One of the first “traps” that can snare your design occurs when you do not understand your limitations. Every day, fire alarm systems become more complex. At the same time, research provides better background for detection design and more information on the limitations of detection. Of course, for you to make an informed decision to assist in the design, you need know about the research and all new building and fire code requirements.

You will find much of the new detector layout information developed as a result of current research in the Annex “A” of NFPA 72 2010, the National Fire Alarm Code. Ensure you have up-to-date knowledge and that you have a track record of ever-growing experience. No contractor does more poorly than the one who refuses to learn, the one who repeats one year of experience.

Furthermore, know when to ask for help. Only when you know your limitations and when you know when to ask for help can you serve the best interests of your customers.

Additionally, you need to know the limitations of the fire alarm system components, for example, of each type of detector you might use in your design. Many contractors fall into a trap when they try to overextend the spacing for smoke detectors. They assume that the spacing considerations provided in the code serves as a recommendation. Yes, closer spacing will generally provide better detection because the detector conceivably will be located closer to a potential fire. But, the balance comes from having the right amount of detection without increasing the false alarm potential of the design.
Another trap awaits the contractor who does not truly understand the audibility and intelligibility requirements for audible notification appliances, as stated in the code. If the design/build fire alarm system will include mass notification, the number of speakers will greatly increase based on system intelligibility concerns. This means, of course, that the contractor will need to know the basics of sound and communications before proceeding with the design. If the system will not use voice evacuation for notification, audibility will become the prime concern. In either case, do not design a system that is not code compliant to save the owner money.

You will want to have the required test equipment to prove you have designed the system correctly. You must prepare to defend your design against an AHJ. Also, remember that, in a fire alarm system design/build scenario, you are considered the expert. Do not let the owner dictate specific coverage.
Even though you perform the design/build of the system, you will still need the proper documentation to ensure that the AHJ approves the installation. This documentation includes the fire alarm system operational matrix, voltage-drop calculations and battery calculations. As a contractor, you will develop the operational matrix based on conversations with both the owner and the AHJ. You will ultimately tell the manufacturer’s technician how to program the particular fire alarm system.

For the “build” part of design/build, you will still need to ensure you install all equipment conforming to the manufacturer’s published instructions, approved plans, and the applicable codes and standards that you referenced in your design. You must assume the responsibility to ensure the programming is correct and matches the operational matrix that you developed during the design process.

Finally, you need to provide a proper acceptance test and commissioning of the fire alarm system, as well as the close-out documents. Your design/build fire alarm system still must include as-built drawings and system operational documents.
Remember, design/build doesn’t mean cutting corners in the project development and installation.

MOORE, a licensed fire protection engineer, frequent speaker and an expert in the life safety field, is a past chair of the NFPA 72 Technical Correlating Committee. Moore is a principal with Hughes Associates, Inc. at the Warwick, R.I., office. He can be reached at

About the Author

Wayne D. Moore

Fire/Life Safety Columnist
Wayne D. Moore, a licensed fire protection engineer, frequent speaker and an expert in the life safety field, is a principal member and past chair of NFPA 72, Chapter 24. Moore is a vice president with JENSEN HUGHES at the Warwick, R.I., office. He c...

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