Complex sentence: Many of the Catalan architects of his time opposed Cerdà's ideas, even accusing him of promoting socialism; in the end, however, they designed the Modernist façades that brought fame to the district.
Split into simpler sentences: Many of the Catalan architects of his time opposed Cerdà's ideas, even accusing him of promoting socialism. In the end, though, they designed the Modernist façades that brought fame to the district.