Garnier became an apprentice of Louis-Hippolyte Lebas, and after that a full-time student of the École royale des Beaux-Arts de Paris, beginning during 1842.

The subject of his final examination was titled:"Un conservatoire des arts et métiers, avec galerie d'expositions pour les produits de l'industrie".

The new submissions were sent to the jury in the middle of May, and on 29 May Garnier's project was selected for its "rare and superior qualities in the beautiful distribution of the plans, the monumental and characteristic aspect of the facades and sections".

[4] Garnier's wife Louise later wrote that the French architect Alphonse de Gisors, who was on the jury, had commented to them that Garnier's project was "remarkable in its simplicity, clarity, logic, grandeur, and because of the exterior dispositions which distinguish the plan in three distinct parts—the public spaces, auditorium, and stage ... 'you have greatly improved your project since the first competition; whereas Ginain [the first-place winner in the first phase] has ruined his.

Many of the most prestigious monarchs of Europe attended the opening ceremony, including the President of France's new Republic, Marshal MacMahon, the Lord Mayor of London, and King Alfonso XII of Spain.

The people who entered the massive building, spanning nearly 119,000 square feet (11,100 m2), were generally awed by its immense size and extensive ornamentation.

He was influenced by the Italianate styles of Renaissance artisans such as Palladio, Sansovino, and Michelangelo, perhaps[citation needed] the result of his many visits to Greece and Rome during his lifetime.

Aside from being fireproof, steel and iron was much stronger than wood, allowing it to successfully withstand the countless heavy tons of marble and other materials heaped upon it without breaking.

[11] The huge ornate granite pedestal was created in Aberdeen by Alexander McDonald & Co.[12] The information concerning Garnier's work on the Italian Riviera is taken from the inventory of Bouvier.