What do you call the little "shed" structure on the rooftop that has a door, usually metal, that leads to the stairway in English? You see it in action movies all the time when they're fighting on the roof. The one I need in my context is only for stairs, not for elevators or pulleys or anything. "En la cubierta del edificio se ubicarán los equipos de climatización y para acceder a la misma se dispone una escalera interior que desembocará en un casetón." "The HVAC equipment shall be located on the rooftop of the building and be accessible via an indoor staircase that goes up to a CASETON on the roof." Thanks!