Following its own hurricane-preparation advice, St. Petersburg-based American Strategic Insurance has built a headquarters designed to withstand a Category 5 hurricane. The 110,000-sq.-ft. building is the first phase of a $42-million expansion by the company. ASI has added employees, too, more than 100 during the past 18 months. It employs 330. Founded in 1997, the company sells insurance in 24 states and has $878 million in premiums and $421 million in policyholder surplus.