The remaining part of Fazenda Guaquica was gradually acquired by local residents such as Luiz Fávero, the Teressari family, and João Berton. Fávero moved to the urban center in 1946 and continued the warehouse business previously managed by the Hermann family. Electricity was installed on the main street in 1945, and public lighting followed in 1947/48.

In the 1940s, Alfredo Francisco Guimarães (known as Alfredo Peixoto) acquired plots and built five houses within six months. This period marked significant urban development in Engenheiro Coelho, with growing commercial and service activities.

According to Claudete Aparecida Soares, in 1947 an airfield was inaugurated, largely due to the efforts of Lázaro Silva (Lazinho), a dentist and airplane owner. He maintained friendly relations with well-known aviation figures and aeroclubs, which held exhibitions in the region.

From 1950 onward, population growth was slow, with a major highlight being a subdivision in 1954 by Pedro Forner. In 1958, the São Pedro Church was built. In 1963, a telephone center was inaugurated. In 1968, an artesian well was opened, helping to alleviate water shortages, and water supply points were installed.

Between 1969 and 1972, water connections reached all homes and a sewage network was installed along the main avenue (Pedro Hereman) and nearby streets.

From 1977 onward, under Mayor Rubens da Silva Harros, the city saw major improvements: better lighting, paved streets, a water treatment station, expanded electricity and telephone networks, a police station, and the opening of bank services (Bradesco and Caixa Econômica).