In some ways, Yosuan Crespo’s real estate office resembles any you might find in New York, London or Tokyo. There are slick posters of hot properties hanging from the ceiling, a steady stream of hopeful buyers and sellers, and a constant clack of computer keys.

But Crespo’s headquarters in central Havana’s trendy Vedado neighborhood is actually somebody else’s breezy front porch. The computer’s only connection to the Internet is a creaky dial-up link, and Crespo is careful to say he’s not operating as a broker, since the job is still technically illegal.