As a private architect he produced the designs for the residences of Secundino Lozana (El Cortijo) in Barranquitas barrio-pueblo[4] and Dionisio Trigo in Santurce, the General Electric store in San Juan, Colegio San José in Río Piedras and the Casino de Puerto Rico in El Condado.
Carmoega also designed the Capitol Building, the University of Puerto Rico Main Campus at Rio Piedras, the School of Tropical Medicine, and the Mayaguez City Hall, all listed on the National Register.
In his interest to preserve Hispanic traditions in the wake of the recent change of sovereignty of Puerto Rico from Spain to the United States, Carmoega utilized the Spanish Baroque and Neo-Mudejar vocabularies in his designs, emphasizing the use of glazed, mosaic tiles in many buildings.
[3] The Plaza de los Perros in Ponce is a fine example of this latter style, incorporating glazed mosaics, horseshoe arches, and galleries in a mosque-like space for commercial usage.
Approximately 48 cubic feet in size, the collection contains architectural drawings, photographs, artifacts, textual documents, and publications.