Editing Byzantine architecture (section)

==== Construction ====
Hagia Irene is composed mainly of three materials: stone, brick, and [[Mortar (masonry)|mortar]]. Bricks 70&nbsp;cm x 35&nbsp;cm x 5&nbsp;cm were used, and these bricks were glued together using mortar approximately 5&nbsp;cm thick. The [[building material]]s chosen for the construction of the church had to be lightweight, durable, and strong. Volcanic materials were chosen for this purpose, as volcanic concrete is very light and durable. Perhaps the most definite feature of the Hagia Irene is the strict contrast between the interior and exterior design. While the plain outside composed of stone and brick favors functionality, the interior is decorated in elaborate mosaics, decorative marble, and, in some places, covered in plaster. Another important characteristic of the church include two domes that follow one behind another, the first being a lower oval, and the second being a higher semi-circle.<ref name=":0" />