The twin imperatives steering the flurry of recent museum transformations resemble a yoga technique: expand and relax. It has been a boom time for some while now, but growth tells only part of the story and increasingly, a smaller one. In their drive for more space and higher attendance figures, large art museums in America are being refashioned to strike a casual demeanor and achieve an integrated relationship to their urban surroundings. These are renovations of institutional philosophies as much as buildings.

The Whitney, relieved of its weighty uptown building—which the Met is leasing while replacing its own late-1980s modern wing—is diverting pedestrians from the High Line into its new downtown home, offering them art and even more elevated views from outdoor terraces. And MoMA is busy scrubbing hauteur off its chilly Yoshio Taniguchi–designed expansion, hiring Diller Scofidio + Renfro to expand galleries, improve circulation, and, in an effort to make more of the ground floor publically accessible, add unticketed exhibition space to a ballooning lobby.

As museums loosen up, they’re becoming more flexible about designers’ credentials. I would wager that Diller Scofidio + Renfro earned the MoMA job less on the merits of their museum work than on their successful revamps of the High Line and Lincoln Center—two New York has-beens made over as interactive open-air attractions. The San Francisco Museum of Modern Art, which opened a $305-million expansion last month, commissioned architects Snøhetta in large part because of the Norwegian National Opera and Ballet. Rising out of the Oslo harbor, the landform-like structure buries the performance functions under an inclined public plaza that, upon completion in 2008, burnished the firm’s reputation for making human-centric and photogenic places. Snøhetta did not have much experience designing spaces for art, but SFMOMA made other demands. “We really want the museum to be much more outward-looking, to open up the doors and bring the public in,” the museum’s director, Neal Benezra, told the New York Times in 2011, when plans were unveiled for a ten-story addition to its South of Market building, a sober brick-veneer edifice with a mouse-hole entrance designed by the Swiss postmodernist Mario Botta and completed in 1995. “We want it to be an embracing, luminous space where you can get good coffee, a place where people come and meet their friends.”

The existing five-story stepped building posed space problems. In 2009, attendance and collection already swelling, the museum secured a century-long loan of postwar blue chips from Gap founders Doris and Donald Fisher (the Fisher collection now constitutes the bulk of the work on view). Botta’s imperious tone, too, was at odds with the institution’s softer message. If barely a decade or two ago the astringent rationalism of Botta (and, in a different way, Taniguchi) was to modern art museums the keeper of a high-middlebrow flame, the white-hot contemporary art market and the hordes of tourists flooding gentrified cities have them going casual, an effect that is especially pronounced in San Francisco, where the tech industry is reshaping the city around a mixture of innovation and inequality, and drawing international attention.

Snøhetta fits in comfortably here. More than a traditional architecture practice, the Oslo- and New York–based multinational resembles IDEO, the stalwart design and innovation consultant. In addition to architecture, it creates landscapes, interiors, brand design, and, soon, new banknotes for Norway. Part of Snøhetta’s success as a company lies in how well it mines the Scandinavia-meets–Silicon Valley ethos that undergirds large swathes of our present culture (a mostly affluent, white, American and European culture, granted). In its most caricatured instances, this is a culture of city dwellers who yearn for the outdoors; “disruptors” who work from Eames chairs and communal desks; digital craftspeople who spin bespoke wares. This is a culture that aspires to a lifestyle of purity and simplicity in every consumer choice, yet whose material expressions can be quite baroque (urban farms, rough-hewn farm tables in minimalist apartments).

On its website, Snøhetta describes its working methodology as the “simultaneous exploration of traditional handicraft and cutting edge digital technology.” On the facade of the SFMOMA addition, there is a similar kind of statement. If the view from the front of Botta’s brick structure is simply a cream-colored slab shaved off at slight angles along the top and side, the volume’s obverse is a bulbous form clad in over seven hundred unique fiberglass-reinforced polymer panels inspired, we are told, by the fog and waters of the San Francisco Bay. The ripples may have been generated by algorithms and carved by robots, but Snøhetta embedded the panels with a natural touch: silicate crystals from nearby Monterey Bay. The panels were fabricated by Kreysler & Associates, a Bay Area firm that grew out of the boat industry and has made numerous large-scale public sculptures for Claes Oldenburg and Coosje van Bruggen (Pop art confections such as twenty-foot ice-cream cones and banana peels). Here Snøhetta has selected a more serious subject, but earnestness can inspire a kind of kitsch. Whereas the Oslo opera conflates an architectural element (sloped roof) and natural formation (glacier) to produce a new relationship between the public and the landscape, the facade arrests the ephemeral coastal atmosphere in a frothy simulacra the pallor of steamed almond milk. As an image, however, it has currency—a cunning triangulation of the local terroir (coastal environment, technology, and capital) that is globally recognizable.

If SFMOMA has a recent precedent it is less Guggenheim Bilbao than Tate Modern Turbine Hall, which did not inspire the growth of museum lobbies but dissolved them altogether: You step off the street and directly into a gallery. Snøhetta’s extension stretches a full city block from Minna Street to Howard Street, where there are two new entrances and a double-height street-level gallery with floor-to-ceiling glass—literally the clearest expression of the museum’s refashioned identity. Here, visitors are greeted by Richard Serra’s Sequence, 2006, a sculpture resting in an expanded field of pricey concessions and 45,000 square feet of unticketed gallery space. This space, which starts at Sequence, extends up amphitheater steps to a second-floor level containing a satellite museum store, education space, and a large Sol LeWitt wall drawing; then it turns ninety degrees (on axis with the original Third Street entrance) and continues, following a flight of stairs, into Botta’s atrium, a tall, oculus-topped square ringed by a museum store, restaurant, and auditorium (by 2017, two enormous paintings by Julie Mehretu will flank the atrium). What is most generous about this free gallery space, though, is the way in which it effectively creates a new route through the city block, enabling new connections with Yerba Buena Gardens, a public park sited between the museum and the convention center.

Yet despite the effectiveness of this continuous passage on an urban scale, an odd dynamic emerges between the two buildings themselves. The natural light, bright white walls, and openness to the street of the new building have sapped energy from the existing one—particularly the atrium, which is no longer the heart of the museum, as it was designed to be. The strong centrality and unadulterated symmetry of the Botta building make it intolerant of change. Remove one part—such as the black-granite staircase that originally soared up the atrium toward the oculus—and the whole space gets off kilter. In its stead are cheery new maple steps connecting the first and second floors. They leave the atrium feeling even more solemn, reacting to Botta’s formal bombast without reckoning with it. And this is the paradox: The binary mantras that informed the redesign—old SFMOMA is a bunker; new SFMOMA is light filled and open—have been crystallized rather than overcome.

While Snøhetta’s relationship to the Botta building wavers between begrudging deference and bald indifference on the exterior and ground floor, it transitions to neutralization on the gallery levels. The existing galleries—well-proportioned enfilades around the atrium—have been maintained, beginning on the second floor (accessible from the new ticketing area) and then on levels three, four, and five, where they merge with the addition (new galleries continue on floors six and seven of the extension). Here, seamlessness is the strategy: The floor levels are contiguous, and Botta’s material palette, white sheetrock and blond-maple flooring, lines a record-breaking expanse of exhibition space. With a combined 146,000 square feet of galleries, SFMOMA has—for the moment—the most display area of any museum in the US devoted to modern and contemporary art (MoMA is set to add 50,000 square feet to its existing 125,000 ). Functionally, Snøhetta has managed an efficient plan—not an insignificant feat considering the museum expects 1.4 million annual visitors following the reopening.

In the 2011 Times article presenting the design, Dykers asked, “Is it a building filled with art with some people in it, or a building filled with people with some art in it? There needs to be enough social space to make people feel comfortable in what can be an austere environment, the white box.” The subtle oppositions—of comfort and austerity, social space and gallery space, people and art—reinforce the schisms presented to large contemporary art museums today. As ground floors of museums mutate into free entertainment, with galleries reserved as premium content—the former following the logic of hospitality management and the latter clinging to standardized models—it is more urgent than ever for architects to define the connections between these two realms. This interstitial zone might be the last place where architects can still gain a foothold, and where museums—operating within an ecology with art fairs and “museum-quality” gallery shows—can set themselves apart.