"UB-5" was laid down by Germaniawerft in Kiel on 22 November. As built, "UB-5" was long, abeam, and had a draft of . She had a single Daimler 4-cylinder diesel engine for surface travel, and a single Siemens-Schuckert electric motor for underwater travel, both attached to a single propeller shaft. Her top speeds were , surfaced, and , submerged. At more moderate speeds, she could sail up to on the surface before refueling, and up to submerged before recharging her batteries. Like all boats of the class, "UB-5" was rated to a diving depth of , and could completely submerge in 33 seconds.