A recreational vehicle is disclosed providing living space extensions with improved actuation and alignment systems, sun deck extensions, a deployable stairway, and a stowable tub. In some embodiments, the living space extension may be actuated by at least one self-centering rack and pinion system. In another embodiment, the alignment system may provide at least one tension cord for maintaining the extension in an upright position. The sun deck extension may be provided with actuatable sidewall panels configured to provide a parapet on at least a portion of the extension. The stairs may be provided with sliding treads coupled to a stringer, and the tub may be retractable and configured with a retractable bed and cover.