Balustrade - a railing supported by short posts or pillars (balusters).
Source: Fleming, Honour, and Pevsner. The Penguin Dictionary of Architecture And Landscape Architecture. Fifth edition, 1999 (paperback).
Banded rustication - large stone blocks separated from each other by deep
Coffer - an ornamental, sunken panel on a ceiling.
Cupola - a small dome on a base crowning a roof.
Dome - a curved vault (arched surface) on a circular base.
Façade - the front or face of a building.
Festoon - carved ornament of a garland of flowers and fruit tied with ribbons and
suspended from two points.
Oculus - a circular window or opening.
Pavilion - an ornamental building, often in a garden.
Pier - the solid mass between windows, doors, and other openings; a rectangular
Pilaster - a rectangular support slightly projecting from a wall.
Portico - an open, roofed space forming an entrance.
Rotunda - a circular room that is usually domed.