Visitor experience about to change at Salt Lake City’s Temple Square. Here’s how and why.

Mormonism’s iconic Salt Lake Temple, in the heart of Utah’s capital, will close Dec. 29 for renovation, but the square surrounding it — as well as the historic domed Tabernacle and nearby Assembly Hall — will remain open during the four years of construction.

Make no mistake, though, the experience for visitors to Temple Square, one of Utah’s most popular tourist draws, will change.

There still will be Christmas lights on the square in the winter and tulips adorning the church’s downtown campus in the spring, but their location and number will shift as the new landscape takes shape.

The South Visitors’ Center will be demolished and the North Visitors’ Center, while remaining open, will be used for “guest services,” including restrooms and overflow seating for Tabernacle events.

The giant Conference Center, across the street, will become the main venue for the Temple Square “guest experience,” Tanner Kay, manager for guest services, said at a Wednesday news conference.

The massive building, used mainly for the twice-yearly General Conferences of The Church of Jesus Christ of Latter-day Saints, Kay said, will be the new home of art exhibitions, temple artifacts, a cutaway model of the sacred structure and an orientation film about the temple’s history.

A replica of the Christus, a marble statue of the resurrected Jesus by Danish artist Bertel Thorvaldsen, will remain in the North Visitors’ Center, Kay said, and a second one will be installed in the Conference Center.

The center’s balcony and roof, he said, also will give visitors a perfect vantage place to view the ongoing renovation and seismic-retrofitting of the temple.

As to the temple interiors, Andy Kirby, director of historic temple renovations, promised that they would be enhanced and improved but remain essentially the same.

The hand-painted murals in ordinance rooms will be cleaned and repaired, leaving the colors “brighter and more vivid.”

The rituals performed by live actors will remain part of the ceremony, he said, but screens will be added to the ordinance rooms so the filmed version can be shown to those who speak a language besides English. Such sessions will have to be scheduled in advance, Kirby said. They will not be done routinely.

The temple’s annex — added in the 1960s — will be torn down and replaced by an “architecturally sympathetic” addition, he said, which will be compatible with the original building materials, forms, millwork and windows.

The original baptistry, where Latter-day Saints do proxy baptisms for the dead, was much larger until it was downsized to accommodate 1960s heating and cooling elements, Kirby said. This renovation will restore the baptistry to its original spacious area.

That’s because today’s mechanical needs can be accomplished in a more compact, less-intrusive way, he said. And those are among the elements that most need upgrading — wiring and plumbing — while adding ramps and elevators for wheelchair access.

The granite exterior will get a “significant seismic upgrade to help the building withstand a large-magnitude earthquake,” explained Brent Roberts, managing director of special projects.

It will involve reinforcements threaded from underground through the temple and its 223-foot-tall spires intended to restructure the foundation and install a series of base isolators to lessen the effects of seismic shifts, similar to work completed on the nearby Tabernacle about a decade ago.

Digging around the base will have to be done in careful stages to ensure the temple’s stability, Roberts said.

The finished work will look more like the 19th century, said Emily Utt, curator of the church history department.

The expense and care to renovate the Salt Lake Temple are worth it, she said. “It is the symbolic center of the church — and the community.”

The temple was begun by Mormon pioneers in 1853 and dedicated 40 years later. It is slated to reopen in 2024 with a public open house — allowing outsiders to view for the first time since 1893 what previously only faithful Latter-day Saints have ever seen — followed by a rededication.

And that golden Angel Moroni, which sits atop the temple, blowing his horn? He will be taken down and spruced up but, in the end, will be back on his perch in perpetuity.