Complex sentence: Unfortunately this project was not carried out, though there are currently plans by the Chilean architect Christian Matzner to take up the project, which if completed would become the first of Gaudí's works to be constructed in the Americas.
Split into simpler sentences: Unfortunately this project was not carried out, though there are currently plans by the Chilean architect Christian Matzner to take up the project. Once completed it will become the first of Gaudí's works to be constructed in the Americas.