It took less than a month to sell half the units in a Sao Paulo luxury apartment building earlier this year, even though construction won’t be complete until 2022. And one brokerage that specializes in high-end real estate saw its revenue double in the first four months of this year.

The luxury residential-property market in Brazil’s biggest city is booming with demand from rich Brazilians, fed up with the toll record low interest rates are taking on their portfolios. Gone are the days of double-digit returns on simple treasury securities, so many of the rich are trying to capitalize on soaring prices in the high-end real estate market.