Notwithstanding the exemptions set forth in Section 4-357(f) and Section 4-357(g) of this Division, only the following universal design requirements in this Division shall be required for townhouses and two over two's: Universal Design: Interior Hallways, Doorways, Stairs. Hallways shall have a 42-inch-wide minimum width measured from wall to wall. Doorways shall have a minimum width of 36-inches and all doors shall contain levers for accessible access. Interior stairs shall be able to accommodate the installation of a chair lift, with an electrical outlet within four feet of the stairs. Universal Design: Bathroom. Continuous wall reinforcement at toilet and bathroom fixtures shall be included to enable easy retrofitting with grab bar(s). All wall reinforcement shall be capable of resisting shear and bending forces of a minimum of 250 pounds. Controls on sinks, tubs, showers, and toilets shall be easily accessible or usable by persons with disabilities. Universal Design: Smoke Detectors and Fire and Carbon Monoxide Alarms. Audible and visual smoke detectors, fire alarms, and carbon monoxide alarms shall be installed pursuant to the IBC.