Forget simple words like preservation. What has occurred at the otherwise nondescript corner of 10th and Howard streets in San Francisco is nothing less than a resurrection — one that shows us how today’s cultural forces can alter the past, salvaging old treasures yet using them in ways their founders could not have conceived.

The juxtaposition involves the former St. Joseph’s Catholic Church, a long-closed landmark that has been restored with immaculate precision. The domed cupolas high above Howard Street again shine with gold leaf. Marble floors have been released from vinyl bondage. The immense sanctuary wears a fresh coat of smooth white plaster.

But our Romanesque Revival landmark no longer houses a religious congregation. It’s now an exclusive semi-private club with a theatrical decor that blends the sacred and the profane — complete with toilets where the confessionals once stood and sculpted limestone hounds poised on either side of the raised former altar area.

If the pairing is incongruous, the oddest detail of all may be that St. Joseph’s has survived.

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The building was consecrated in 1915, with a design by John Foley intended to evoke the spiritual majesty of European cathedrals. The stucco exterior was formed to look like stone, with an enormous stained glass window between the cupola-topped bell towers. Inside, the barrel-vaulted ceiling tops off at 56 feet. Above and behind the former altar, the ceiling glistens with nearly 100 plaster rosettes painted gold.

The architecture endured amid South of Market’s changes. Thoroughfares like Howard Street attracted car-repair shops and self-storage facilities. Filipino immigrants replaced Irish families in the residential alleyways. By the 1980s, far more people visited the area for late-night clubs than Sunday Mass.

Then came the Loma Prieta earthquake in 1989, which damaged St. Joseph’s and caused it to be red-tagged. The Diocese of San Francisco used the building for storage, while squatters scavenged any metal of value they could pry loose.

Finally in 2008, Chris Foley purchased St. Joseph’s. He hired Page & Turnbull, an architecture firm that specializes in preservation, to craft a design that would turn back the clock but make room for tech-oriented office space. After the project was approved in 2010, five years passed before federal tax credits were lined up. Palisades Builders joined Foley along the way.

Shortly before construction began, a third building partner stepped in: Ken Fulk, a well-connected interior designer and event planner attracted to the potential of what had been.

“This is the most complicated project I have ever done, by far,” said Foley, a developer active in the area. Not that there are any regrets: “When do you get the chance to bring a building like this back to life?”

Structural work was involved, such as the discreet threading of concrete shear walls into the exterior for seismic strength. Steel tubing was tied to the back wall, also for seismic reinforcement, then screened with vegetation.

The real triumph, though, is conjuring up a serene splendor that probably hadn’t existed since 1915. The sheet metal that covers the cupolas was patched and then coated with gold leaf. Decayed or vandalized plasterwork, such as the moldings on the tall columns that line the sanctuary, was re-created. The surviving stained glass windows were taken apart, cleaned and repaired, then reassembled.

There’s also one large addition, a steel mezzanine that runs along either side of the central hall where aisles once led to wooden pews.

Though it includes a narrow footbridge linking the east and west mezzanines, the addition isn’t jarring. Rather, it creates a vantage point to savor the spatial drama. You’re immersed and yet slightly detached, able to savor such details as the gold accents on the column moldings, or the overlapped tumble of ceiling curves and arched windows along the upper walls.

Amid all this, the rococo flourishes of what Fulk calls the St. Joseph’s Arts Society — part event space, part private club, part gallery and ultra-luxe boutique — are a lavish but harmless distraction.

Fulk is a self-styled “designer of experiences big and small,” with a portfolio that ranges from cocktail shakers at Pottery Barn to the plush interiors of restaurants such as the Cavalier on Fifth Street. He also staged the notorious Big Sur wedding of Napster co-founder Sean Parker in 2010, a gala that resulted in Parker’s paying fines to the California Coastal Commission for staging the elaborate nuptials without a permit.

At St. Joseph’s, the “salons” beneath the mezzanine wings are swathed in drapes and decorated with classical busts. Above the wings, papier-mache black bears loom larger than life. One staircase wears a (presumably) faux leopard-skin rug.

Some people will be seduced by the mannered ostentation. Others will roll their eyes. But it’s relatively restrained by Fulkian standards — and in its own way, a better fit for St. Joseph’s interior than the office space concept. Instead of filling the grand void with a hive of workers, it’s as if there is a stylized theater within a space conceived for ritual, albeit ritual of a different kind.

The other plus is that a major work of architecture received the care it deserves.

For all the social tensions caused by the impact of the Bay Area’s prolonged economic boom, the wealth it generates means we have an abundance of entrepreneurs and investors who want to make a mark. That’s a blessing for buildings like this. Similar structural treasures in other cities might languish until they collapse.

At some point, the good times will fade. There may no longer be a demand for parties in former churches festooned with affectations. Whatever happens, St. Joseph’s has a renewed lease on life — and anyone who contemplates its salvation can share the blessing.

John King is The San Francisco Chronicle’s urban design critic. Email: jking@sfchronicle.com Twitter: @johnkingsfchron