Updating and fine-tuning the oldest and largest library in Istanbul is not a project for the faint hearted, but Turkish international firm Tabanlioglu Architects rose to the occasion, embarking on the sensitive re-organisation of the interior and restoration of the State Library's fabric in 2006.

Located on Beyazit Square, the library was first founded in 1884 and sits in a historical context, adjacent to the Beyazit Mosque – the oldest surviving imperial mosque in the city – and located on the main axis of Istanbul's historical heart, Divan Yolu. Previous uses of the building had involved it being everything from a soup kitchen to a traditional inn (or 'caravanserai').

The architects placed a light and transparent inflatable membrane structure over the building's open courtyard. This filters light through and creates a controlled atmosphere for books and visitors, while abstractly mimicking the library's iconic domed roof.

Transparent glass box pavilions now dot the interior, creating a modern counterpart to the historical surroundings. These enclosed spaces are also able to ensure an optimum atmosphere in which to preserve the library's rare book and manuscript collection.

The flow through the building was tweaked in order to best serve its modern function, so the main entrance is now through the aforementioned courtyard. Modern Turkish publications sit on the second floor, and periodicals on the first, while the ground level houses the rarer, more precious objects of the collection in their cubic boxes.

During the construction works, the remains of a Byzantine church were revealed. These have been preserved and can now be enjoyed through a glass roof – a gesture that highlights Tabanlioglu Architects' careful restoration work and minimal intervention, aimed at respecting the spirit of the historical library.