On the exterior of the Small Hagia Sophia Mosque , the masonry adopts the style of that period in Constantinople: mainly using bricks sunk in thick beds of mortar . The walls are reinforced by chains made of small stone blocks .
In front of the building there is a portico and a court (they were added during the Ottoman period) , with a small garden , a fountain for ablution as well as several small shops .
Inside the edifice , there is a two-storey colonnade , which runs along the north , west and south sides , and bears an inscription in twelve Greek hexameters dedicated to the Emperor Justinian , his wife , Theodora , and Saint Sergius , the patron-saint of the soldiers of the Roman army . The lower storey has 16 columns and the upper one has 18 columns . There are many of the capitals still bear the monograms of Justinian and Theodora .
The main area is square planned measuring 25 x 28 meters . There is a gallery floor that surrounds the whole structure in octagon shape except for the mihrab (niche) . The dome covers the main location of the building and exceeds 15 meters and rises 19 meters from the ground . Nothing remains of the original interior decoration of the church as it is
believed to be covered in mosaics with walls of variegated marble . During the conversion of the building into a mosque the windows and entrance were changed , floor level were raised , and the interior walls were plastered .
