Comprehensive survey, restitution and restoration projects were prepared for Hagia Sophia following structural analyses.
The most extensive republic-era restoration of the Hagia Sophia Grand Mosque is nearing its final stage, with Culture and Tourism Minister Mehmet Nuri Ersoy confirming three of the four phases are successfully completed after touring the site.
Ersoy said the second stage, involving sensitive work on the minarets, main dome, semi-domes and mosaics, was continuing. He said the government was carrying out extensive efforts to protect cultural heritage and pass it on to future generations.
“The Hagia Sophia Grand Mosque, the symbol of the conquest and Fatih’s trust, is one of them,” Ersoy said, referring to Ottoman Sultan Mehmed II, known as Fatih Sultan Mehmet.
Comprehensive survey, restitution and restoration projects were prepared for Hagia Sophia following structural analyses. Strengthening projects were also drawn up for the main dome and semi-domes and implementation began after approval from the relevant conservation board.
During the first stage, restoration was carried out at the tombs of Mehmed III, Selim II, Murad III and the Princes in the southern courtyard. Lead coverings on the tomb domes were renewed, unsuitable materials were removed and windows, wooden shutters and other architectural elements were repaired and conserved. Exterior surfaces were also cleaned.
The historical muvakkithane, or timekeeper’s room, and the primary school were restored. The ablution area at the southwestern corner of the mosque was reopened and a bird deterrent system was
installed.
The second stage includes work on the northern, southern and eastern façades, where cement-based plaster is being removed and cleaning and inspections are continuing.
Ersoy said work on the northeastern minaret had been completed in line with its structural strengthening project. Following structural analyses, part of the minaret was carefully dismantled down to a specified level.
The operation began at the copper finial and continued through six rows of stone and the associated steps. Stainless steel plates and rod systems were installed to improve the minaret’s structural performance against earthquakes.
Digital modeling and ground-penetrating radar scans were also conducted to determine strengthening requirements. Approved reinforcement work has begun in the northeastern and southeastern stair towers.
Cleaning and repair work on the marble window elements is also continuing, with the preservation of original materials prioritized.
Main dome to be strengthened from outside
Ersoy said the main dome and semi-domes would be strengthened as part of an integrated project. As the interior surface is covered with mosaics, the main dome will be reinforced from the exterior.
All lead coverings must be removed for the required repairs and strengthening work. A temporary covering system was installed to protect the dome from seasonal weather conditions and prevent damage to the mosaics.
A platform and scaffolding system was also installed inside the building to allow conservation and restoration work on the mosaics to be carried out safely.
A steel platform supported by four main columns was installed so worship and restoration could continue simultaneously. Marble dismantling, protection and covering works were completed and scaffolding was erected for mosaic conservation.
Laser scanning and photogrammetry were used to document the condition of the mosaics on the interior surface of the main dome. The scans also revealed traces of repairs carried out during different periods, which were incorporated into the relevant project drawings.
Ersoy said interventions were being documented photographically at every stage and a structural monitoring system had been installed.
The third stage focused on preparations for opening the gallery floor to visitors. Visitor routes were reorganized and cleaning and conservation works were completed.
Entrance and exit ramps, a temporary entrance tunnel and ticket booths were constructed, while X-ray and turnstile systems were installed. Marble and wooden surfaces underwent cleaning and localized conservation.
Unsuitable plaster was removed, localized repairs were conducted and original railings were strengthened. Missing and broken glass panes were replaced and wire mesh was installed on windows to prevent birds from entering.
Lighting, security cameras, emergency announcement systems and internet infrastructure were also completed.
Restoration work is also continuing beneath Hagia Sophia. Ersoy said preliminary excavations and documentation had begun in Rooms 1 and 2, the hypogeum section in the northern courtyard and tunnels numbered one through five.
Ninety percent of cleaning work in the Vezir Garden and West Garden areas has been completed. Excavations of the hypogeum in the Vezir Garden were also completed.
Nine tunnel structures were identified in the West Garden. Except for Tunnels 2 and 8, all underwent fill soil removal.
In the 56-meter-long Room 2, damaged vaults were repaired along an 18-meter section using material compatible with the original structure. Similar work was conducted along 10-meter sections of Tunnels 4 and 5.
Structural strengthening with stainless steel supports was completed along 50 meters of Tunnel 4, while work continues along 90 meters of Tunnel 5.
