Related Refinances New Florida Office Building: A new offering for a multiborrower commercial mortgage-backed security comes with its own unique loan-specific bonds. The certificates are secured by 360 Rosemary Ave., Related Cos.’ newly constructed, 313,002-square-foot, Class A office building in the heart of West Palm Beach, Florida. The project wrapped up last year and is fully leased, according to CoStar data. Loan-specific bonds are tied to the performance of one property, whereas other bond certificates in the deal are tied to a pool of loans. The technique is used only occasionally for investment-grade properties.