This project, which houses the Uruguayan branch of McCann-Erickson, the American advertising agency, is a remodeling of and addition to a modern house in Montevideo. The original house, located in a quiet residential neighborhood, is a classic example of fifties modernism and it was a challenge to respect the identity of the original house while responding to the many contemporary functional requirements of the clients. Extensive retrofitting of the existing house, for instance, with up-to-date mechanical and electrical systems was necessary to meet the challenging structural conditions and circulation requests of the client.The house was originally a one-story, three-bedroom structure with an adjoining studio. A second story was later added to the rear of the house. Our project expanded the second story into the front—the façade of the new office space mirrors the façade of the original entrance below. The building, which now accommodates thirty people in two separate offices, is around 5,000 square feet. With a backyard patio and an open-air barbecue for outdoor meetings and parties, the project exemplifies the flexible city code of Montevideo which allows for the coexistence of residential and ‘soft’ commercial activities such as offices and light manufacturing, thus contributing to a vibrant and multi-faceted urban environment.