Anyone who has grown up in North Texas knows the unmistakable sound of the tornado siren—whether it’s a routine weekly test or a real-life warning, often experienced from the safety of a closet or bathtub. From 1981 to 2010, Texas averaged more tornadoes annually than any other state, with an average of 150 tornadoes each year. These storms have the power to disrupt lives and damage property in an instant, from uprooting trees to leveling homes.
At BHB, we share a deep-rooted connection to the Texas community, and our commitment to tornado safety and storm shelters runs through everything we do. We understand firsthand the importance of designing safe, resilient buildings. That’s why, in addition to designing code-compliant storm shelters for our clients, we’re dedicated to advancing the practice of storm shelter design.
In response to changing regulations in the 2015 International Building Code (IBC), the National Storm Shelter Association (NSSA) developed its certification exam. The IBC, adopted by municipalities across the U.S., mandates that certain new buildings—based on their use and geographic location—include storm shelters built to withstand natural disasters, in compliance with ICC 500 standards.
To meet the growing demand for expertise in storm shelter design, the NSSA created its Advanced Professional (AP) program. This program offers certifications across multiple engineering disciplines, including structural, mechanical, electrical, civil, and architectural engineering. To achieve AP status, candidates must pass both a general knowledge exam and a specialty-specific exam. They must also serve as the architect or engineer of record on an approved storm shelter project.
Two of BHB’s mechanical engineers, Allen Grammer and Kirk Plum, are NSSA Accredited Professionals. Both serve Texas school districts by designing and conducting peer reviews of storm shelter plans. Allen also serves as Vice-Chair of the NSSA ICC 500 Chapter 7 workgroup, where he plays an active role in reviewing and updating code provisions to ensure they stay aligned with the latest technological advancements and evolving climate data.
Allen’s work on both the exam committee and the ICC 500 workgroup has deeply influenced his approach to emergency storm shelter design. One notable insight he gained was the flexibility allowed by the ICC 500 standards in storm shelter ventilation systems. For instance, during a tornado, wind pressures can easily exceed the pressure rating of typical ventilation ductwork construction. In that case, while the shelter would still be protected from dangerous flying debris, ductwork could be damaged during the tornado event, which could prevent proper operation during the emergency. Because of this, BHB designs low-cost pressure relief into our ductwork at the shelter penetration, allowing excess pressure to vent from the system without damage to the mechanical systems. This solution helps maintain a more secure environment, helping to give occupants peace of mind during a stressful situation.
At BHB, we take pride in applying this knowledge to real-world projects. For example, one of our recent storm shelter designs incorporated these ventilation strategies, ensuring occupants’ safety and comfort while meeting stringent code requirements. We provided these pressure relief systems for the Vanguard Preparatory School in Aledo, which had its groundbreaking event on Jan. 28th, into each duct penetrating the storm shelter envelope. This project design has passed a third-party storm shelter peer review, and construction is about to begin.
By focusing on safety and comfort, we design buildings that are not only prepared for extreme weather events but also incorporate innovative solutions that improve the overall experience for occupants. At BHB, we remain committed to helping our clients navigate these challenges, providing them with shelter solutions that are both safe and effective in the face of nature’s unpredictability.