Fabiani's first large-scale architectural project was the urban plan for the Carniolan, now Slovenian capital Ljubljana, which was badly damaged by the April 1895 Ljubljana earthquake. Fabiani won a competition against the more historicist architect Camillo Sitte, and was chosen by the Ljubljana Town Council as the main urban planner. One of the reasons for this choice was Fabiani was considered by the Slovene Liberal Nationalists as a Slovene. Second reason was that he knew Ljubljana better than Sitte and prepared really good and modern plan. With the personal sponsorship of the Liberal nationalist mayor of Ljubljana Ivan Hribar, Fabiani designed several important buildings in the town, including the L-shaped school in the Mladika Complex facing Prešeren Street (), which is now the seat of the Slovenian Foreign Ministry.