Vatican spokesman Federico Lombardi said the new pontiff would remain in the 120-room guesthouse among other members of the clergy "until further notice."
"He is trying out this type of simple living with other priests," Lombardi said, without saying when, or even if, the pope would move into the papal residence.
"This morning he let his fellow cardinals know that he will keep living with them for a certain period of time."
The pontiff has been taking his meals in the common dining room of the guesthouse and celebrating 7am mass with Vatican employees in its main chapel.
However Lombardi said the pope had moved out of the simple room he was allocated during the conclave that elected him and is now staying in a slightly larger suite where he can receive visitors.
The Argentinian pope, who was appointed on March 13 after the historic resignation of his predecessor Benedict XVI, has won praise for his no-frills lifestyle and focus on humility.
Lombardi said the official residence, known as the Apostolic Palace, was ready for its new tenant. Local media have reported the pope finds the residence too spacious.
The apartments overlooking St Peter's Square were first occupied by St Pius X in 1903. The residence was completely renovated by Pope Paul VI in 1964 and has been slightly modified by each successive pope.
The pope, a son of working class immigrants has shunned much of the Vatican tradition by choosing simpler and less costly alternatives when it comes to both papal clothes and accessories.
The Casa Santa Martha guesthouse was built in 1996 specifically to house cardinals during a conclave, but also serves as a permanent residence for priests and bishops who work at the Vatican.