oriel

An oriel is a cantilevered projecting bay with windows, generally with a rounded or chamfered form, which allows greater natural light as well as improved views and additional floor space inside a building.

An oriel is similar to a bay window, except that an oriel projects over empty space while a bay window extends to the ground or to the base of the facade.

The windowed bay increases the interior space while projecting above open space. A ground-supported continuation down to the facade base has the bay-window arrangement; the rounded or chamfered outline is common but does not supply that distinction.