What is the name for walls that extend above the roofline on a flat roof?

The term for walls that extend above the roofline on a flat roof is a parapet wall. Parapet walls serve several important functions in building design and fire safety. They act as a protective barrier, preventing people from falling off the roof. Additionally, parapets can help minimize wind uplift on the roof structure and can also provide fire protection by acting as a barrier between different buildings or structural elements.

Parapet walls are also important when it comes to drainage and preventing water from accumulating on the roof edges, which can lead to leaks and structural damage over time. They can enhance the aesthetic appeal of a building, especially in urban environments where roofs are visible from surrounding structures.

While the other terms listed have specific meanings in construction and design, they do not refer to walls that extend above the roofline on a flat roof. For example, a balustrade is typically a railing supported by balusters, used on balconies or staircases. A fascia is the horizontal board that runs along the edge of the roof, and a ridge wall typically refers to a wall at the peak of a pitched roof, not flat roof structures.