By selecting this option, your cupola vents will be open and allow airflow in and out of the interior of the structure. Generally a cupola is used as a decorative accent that is closed off to the a space below the roof, but making this decoration functional can provide additional benefits in some situations. Ventilation can be a concern if the structure is enclosed with privacy panels or 4 track windows. A cupola box will be incorporated into the frame of the roof, so there is nothing more to do when building your gazebo. Our square structures, as well as Octagon and Dodecagon gazebos, have open and functional cupolas by default, mostly because it allows for easier installation, but including this feature on any cupola can be a great way to get fresh air through the roof.