Purpose of vertical extension of curtain-walls and structural elements over the roof
 

What's the purpose of vertical extension of curtain-walls and primary structural elements over the roof of tall buildings?

In many tall buildings, parts of primary structural elements and/or the curtain-walls are above the occupied space and the roof.

See this image as a clear example : https://architizer-prod.imgix.net/me...press&cs=strip

They don't separate interior and exterior spaces; in fact, they are only in the exterior space.

How are they called? Is there a specific term to address them?

And what's the purpose of designing and constructing them?

Are they useful to reduce wind-induced noise at the top floors?

Are they useful to reduce wind speed on the roof?

Or are they just for aesthetical purposes?


Thank you

There is typically a lot of mechanical, elevator and other electrical equipment on top of a tall building. The exterior cladding is extended beyond the occupied floors to conceal this equipment. It is called a mechanical penthouse.

And the actual walls are called parapets.