Avedissian, who is considered one of the founding fathers of Lebanese architecture and urban planning, is of Armenian descent.
[2][3] In 1887, Bechara Effendi was dispatched by order from the Porte to assist with the excavations conducted by Osman Hamdi Bey and Yervant Voskan at the necropolis near Sidon, Lebanon which unearthed the Alexander Sarcophagus among other artifacts.
He is credited with discovering new burial chambers and with devising transport mechanisms and superintending the transit of the massive troves to a frigate bound for Constantinople's museum.
Some of his work include the Petit Serail, the Sanayeh school complex, the Ottoman Bank in Beirut.
Avedisian worked closely with Youssef Aftimus who married his daughter Rose in 1899.