When I first saw this #IELTS task, I thought someone misreported it. But then I saw it again - and decided to write. 

One problem I see is that there is little information. My first version was basically over after the overview. Another problem is that it's not exactly clear what to compare. Anyway, here is the 233 words I managed to produce. 

"The diagram shows the fire evacuation plan for the second floor of a student residence hall. The floor has seven bedrooms and two emergency exits with staircases leading to two different meeting points outside. The exit routes, however, are not evenly distributed: one is reserved for three rooms and has a more spacious access area, while the other will have to accommodate occupants from four rooms in a smaller space.

The first staircase, leading to Meeting point 1, is close to bedrooms 1-3, with rooms 1 and 2 adjacent to each other and room 3 on the opposite side. The doors of all three rooms are a short distance from the exit, which ensures that all occupants can reach the staircase quickly. In addition, this exit access area is spacious as there is an empty space the size of a room proximate to the staircase. 

The staircase leading to Meeting Point 2 is designated for bedrooms 4-7, all adjoining each other, with rooms 4-5 located fairly close to it and rooms 6-7 further down the corridor. In front of the exit is an elevator; as it must not be used during a fire, its occupants will have to leave it and evacuate via the stairs. Given the potentially larger number of evacuees and the position of the elevator, this evacuation path is likely to be more crowded in the event of a fire."