CHICAGO (CBS) — In the Vatican in Rome, the Church is on an uncharted course,how and when to elect a new Pope when the old one who is still alive?

It has never been done in modern times.

Vatican insiders are still scratching their heads, trying to figure out how they missed apparent hints being dropped for some time, reports chief correspondent Jay Levine.

In the shadow of St. Peter’s Basilica, tucked away in the Vatican Gardens, behind tall hedges and locked gates, the renovation proceeded almost unnoticed, until now.

The renovation is a building which housed cloistered nuns, soon to be the residence of a retired pope.

“I would to think the pope will really enjoy his time of retirement,” said Cardinal Keith O’Brien.

To pray, think, and write in tranquility with his own chapel and library.

Some at the Vatican now believe the renovation, which began back in November might have been a tip-off.

Others point to the Pope’s telling associates his long pilgrimage to Mexico and Cuba last March was more than he could handle.

Or a symbolic gesture, described by John Sweeney, author of the “Pope Who Quit,” of Benedict praying at the tomb of the only other pope to willingly abandon the seat of St. Peter centuries ago.

“He actually takes off his palium, the stole around was shoulders, and he lays in on the tomb of Celestine the 5th and he never explains why he does this,” said Sweeney.

Vaticanistas are still scratching their heads over what signs they missed; and the real reason, and whatever the reason, the unprecedented announcement has Vatican officials carefully orchestrating his final weeks, moving tomorrow’s Ash Wednesday mass from a local church, to the huge basilica.

His final Wednesday audience on the 27, the day before he leaves, has been moved from the auditorium to the more ceremonial setting of St. Peter’s Square. The world’s cardinals, expected to gather for that final mass, will then get down to business.

“To find out really what people are willing to say about another Cardinal who I wouldn’t know so well but obviously is being spoken about. That’s when you start asking questions,” said Cardinal Francis George.

With the seat becoming vacant on February 28, cannon law set a minimum of 15 days until the start of the conclave. That would be March 15. Assuming the Cardinals would take a few days to elect a successor, that would put the traditional Sunday inauguration mass on the 24th, Palm Sunday, leaving most Cardinals half a world away from their home dioceses on one of the holiest days of the year.

Starting the conclave a bit earlier, say March 10th, still giving the cardinals 10 days, instead of 15, for their informal discussions, could move everything up a week and eliminate the conflict with Palm Sunday. But as one insider said today, this is Rome. Tradition is everything. 15 days means 15 days.