Edifício vs. prédio
While edifício and prédio are synonymous and both mean "building", the choice between them usually depends on formality and regional habits. In general, prédio is the everyday term for residential structures, especially in Brazil, while edifício implies a higher degree of formality, architectural importance, or constitutes part of a proper name.
Edifício
B1This word represents a formal way to describe a constructed structure. It focuses on the architectural aspect or the institution housed within. It is the standard term used in proper names of skyscrapers (like the Empire State Building) and represents the preferred term in formal written Portuguese in both Brazil and Portugal.
O antigo edifício foi transformado em um museu moderno.
(The old building was transformed into a modern museum.)
Não é permitida a entrada de animais neste edifício público.
(Animals are not allowed inside this public building.)
O Edifício Copan é um dos mais famosos de São Paulo.
(The Copan Building is one of the most famous in São Paulo.)
A arquitetura deste edifício reflete o estilo gótico.
(The architecture of this building reflects the Gothic style.)
A segurança do edifício monitora todas as entradas.
(The building security monitors all entrances.)
Prédio
A2This is the most common term in spoken language, particularly in Brazil, to refer to vertical buildings like apartment blocks or offices. In Portugal, it is also widely used for urban properties but can legally refer to any estate or land property. If you say you live in an apartment, a Brazilian will naturally say you live in a prédio.
Moro em um prédio de três andares sem elevador.
(I live in a three-story building without an elevator.)
O síndico do prédio marcou uma reunião para hoje à noite.
(The building manager scheduled a meeting for tonight.)
Estão pintando a fachada do prédio de azul.
(They are painting the building's facade blue.)
Meu prédio fica perto da estação de metrô.
(My building is located near the subway station.)
Os moradores daquele prédio reclamaram do barulho.
(The residents of that building complained about the noise.)
Summary
Use prédio for casual conversations, specifically when referring to residential apartment blocks or generic vertical constructions in a city. Use edifício for formal contexts, when discussing architecture, government structures, or when referring to a building by its specific proper name.