As the doors to Mario Botta’s stalwart brick San Francisco Museum of Modern Art opened in 1995, its central atrium greeted visitors with the Swiss architect’s formidable grand staircase, three stories of floating granite framed by white columns and spotlighted by the serene white glow of the oculus overhead. Architecture critics deemed the stairs a monumental centerpiece reminiscent of Frank Lloyd Wright’s iconic Guggenheim ramp or the bell tower that rises above an Italian piazza. The late Herbert Muschamp described it as “an endless ziggurat that rises toward the turret’s circle of light,” positing that “some will be unable to resist extending their arms in the classic Ziegfeld pose” as they descend the staircase.

It’s gone now.

SFMOMA, currently closed for construction, demolished Botta’s icon last year to make way for the museum’s forthcoming 235,000-square-foot expansion designed by the Oslo-based Snøhetta and slated to open early in 2016. Despite the architects’ vocal reverence for Botta’s work (and the pain these alterations would cause Botta’s many admirers), they and the museum deemed it necessary to remove the stairs to facilitate the flow between Botta’s space and theirs, a white building set to rise 10 stories above the slim site behind the museum. Replacing the original stairs will be a structure far less impressive, a two-story wooden staircase that pivots midway at the landing. The new stairs have little in common with Botta’s — they’re asymmetrical, low-slung, ordinary. Prominent critics decried the move after the museum announced its plans in 2011.

“The decision to remove the Botta stair, while it may make some practical sense in terms of simplifying circulation in the expanded complex, threatens to gut the interior coherence of Botta’s design, turning it into a kind of false front for a Snøhetta-designed museum inside,” the L.A. Times’ Christopher Hawthornewrote.

The loss of an icon, however, shouldn’t be considered a crime against architecture. Botta’s and Snøhetta’s designs are of different eras — not only of time, but of SFMOMA’s mission. The architecture of a museum is an expression of its identity, as we’ve seen in the revamped expansions of both the Perez Art Museum and more recently the Museum of Modern Art, and the lobby is no exception (more on that later).

Back in 1995, former SFMOMA director John R. Lane told the L.A. Times that the museum had instructed Botta to design a building “with some significant exterior character.” The museum had just decamped from its modest first home, the third and fourth floors of War Memorial Veterans Building across from City Hall, to a freestanding building in the industrial, low-income South of Market Area (which locals call SOMA). Botta, greatly influenced by Le Corbusier, Louis Kahn, and his own Italian cultural heritage, assertively announced SFMOMA’s newfound street presence with a monumental brick fortress, noted for a symmetry frequently described as Palladian. The steward of art, nestled in a rough part of town, was crowned by setback rooftops and its enormous oculus.

“The Botta building gave the museum exactly what it needed in 1995, which was a big, strong, muscular presence,” said Neal Benezra, SFMOMA’s current director, in an interview withARTINFO. “We had art inside, and we were going to keep it safe.” But after 18 years, both the museum and its surroundings have evolved dramatically. As attendance has grown, so has SFMOMA’s collection (recently through its partnership with power collectors and Gap founders Doris and Donald Fisher). Today, it finds itself surrounded by myriad shopping and dining destinations. In 2011, a W Hotel went up next door.

Consequently, what the museum needs now is not so much protection for its art but a place to put it. Expansion seemed necessary, yet SFMOMA, which prides itself on its spirit of innovation (it was an early adopter of female directors, photography as a fine art, Jackson Pollock, and the museum website), worried about how the process would transform its identity.

“How do you go from 50,000 square feet of galleries to 130,000 square feet of galleries and a bigger endowment and not lose your soul?” Benezra asked. “How do we not become conservative in the process?” The museum decided that the answer was to provide the public with greater access to its art by lowering its walls, literally and metaphorically, under the clever slogan, “Closed for construction, yet more open than ever.” For the length of its hiatus, SFMOMA will not be renting a temporary space. Instead, it’s sending its artworks out: Mark di Suvero sculptures to Crissy Field, complimenting the views of the Golden Gate Bridge; site-specific commissions to the Silicon Valley suburb Los Altos; photography to less cosmopolitan locales like Bakersfield and Stockton; and towards the end of 2014, a yet-to-be-announced exhibition to Paris. In November, the museum announced that admission for visitors 18 and under would be free beginning in 2016.

When it came to choosing the firm that would design the expansion, SFMOMA had its pick of top international architects — Adjaye Associates, Diller Scofidio + Renfro, Foster + Partners, and Snøhetta — and yet it chose, arguably, the least prominent, and incidentally the only one that doesn’t identify its principals by name. “I think that’s indicative of a lot of things: their willingness to listen, their eagerness to listen,” Benezra said. “That lack of tangible ego has been great.”

Pointing to a picture of Snøhetta’s 2007 Oslo Opera House, with its dramatically sloping facades of white Italian marble and vast expanses of glass, Benezra said that it was ultimately this building that won the firm the job. “If you walk around the back of the building, this is what you see: windows. You look in, and you see the artisans making the costumes, the wigs, and the set designs. I love that for my staff. I love the idea of demystifying what they do in the museum. It’s an openness, not just for the public.”

The desire for demystification runs contrary to Botta’s assertions that the museum is a “spiritual place.”

“People lower their voices when they get close to art,” Botta, who’s designed a number of celebrated cathedrals, told the San Francisco Chronicle in 2005. By contrast, Snøhetta peppered their interior with spaces in which visitors would be allowed to raise their voices and interact, providing breaks from the increased number of formal galleries. On the exterior, the new façade’s 700 individually molded white siding panels — set back at various heights to make room for multiple terraces — create a sense of lightness unlike Botta’s bricks. But the expansion’s most important features are the entrances on all sides of the museum and the glass walls of its first-floor gallery, which offer free spaces to congregate and passersby views into the museum — which brings us back to the museum lobby and what it says about its institution.

Architecture is a powerful tool in the expression of an institution’s identity, as seen in various art museums around the country. On the opposite coast, further south, the Herzog & de Meuron-designed Perez Art Museum (PAM) opened in Miami to near-universal acclaim in late 2013. Following the museum’s directive to connect itself to the public and to Miami’s natural beauty, the Swiss architecture firm wrapped the building in glass, also allowing visitors a peek at the art inside before buying their tickets, or even entering the institution.

“We were the first ones to say that we want to create an open space that is shaded and that is free, instead of a closed jewel box for those people who already know or already want to know about art,” said Herzog & de Meuron partner Christine Binswanger, citing the tendency of museums to hermetically seal art behind heavy doors, as well as features like imposing ticket counters and empty lobbies, as exclusionary gestures. New York’s Museum of Modern Art,a target for 2011’s anti-elitism Occupy Museums! movement and an institution that’s been berated for charging $25 admission, for example, certainly doesn’t show a lot of art for free in the sterility of its lobby, the buffer between the have-paids and have-nots, although MoMA too now seems to be catching on to the trend. In a move MoMA director Glenn D. Lowrydescribed “a major component of the Museum’s desire for greater public access,” the museum just unveiled its own plans for a glassy expanded street presence designed by Diller Scofidio + Renfro.

“It’s a very nice gesture of a kind of new ethos: To make publicly accessible, unticketed space that is attractive and has cultural programming,” he told the New York Times. (Their own version of the Botta staircase is the cherished Tod Williams Billie Tsien-designed building next door, which the museum plans to demolish.)

In the past, SFMOMA has also been guilty of exclusion. “[T]alk about piazzas and urban renewal doesn’t change the fact that a visitor pays to go upstairs before seeing a single painting or sculpture,” Michael Kimmelman wrote in the New York Times in 1995. “For all you can tell, Mr. Botta’s forbidding and theatrical lobby might belong to an office tower or mall, instead of a museum.” The transparency of Snøhetta’s new design, however, removes some of the barriers between institution and urban fabric.

Botta’s beloved staircase has gone, but so too have the problems associated with it. It had a tendency to stop people — visitors rarely ascended them. Instead, they would marvel for a minute, then make their way to the elevators. And the lower, less grandiose staircase is exactly what SFMOMA, and indeed the elitism of the art world, needs now — a user-friendly sense of approachability, bereft of any holy allusions.