Despite changing needs and tastes, Venturi Scott Brown's threatened extension to the Museum of Contemporary Art San Diego warrants preservation simply because their names are attached to it, says Mimi Zeiger.

Consider this a postcard from "Ugly Valley". You know this place: it isn't a downtrodden Catskills resort or the smoky grey Valley of Ashes from The Great Gatsby, which so forbearingly illustrates modernism's grim after effects. This is an anti-picturesque spot on the fringes of mainstream taste populated by the detritus of the 20th Century.

Here, Michael Graves's Portland Building sits alongside Philip Johnson and John Burgee's AT&T Building. Ugly Valley (just a hill over from Uncanny Valley) is a place bounded by temporality.

The phrase, lifted from conversations with Michael Kubo and Chris Grimley (editors of Heroic: Concrete Architecture and the New Boston, and champions of both brutalism and late modernism), describes a dip in the sine curve of a building's popularity that generally occurs about 40-60 years into its history.

Such a downturn is dangerous because it represents the vulnerable period in which many works of architecture are destroyed because their original use value has expired, and their styles have fallen out of public favour.

VSB's design is a young addition to "Ugly Valley"

Some styles, like art deco or arts and crafts, were rescued from the trench by the early activism of preservationists, while other structures succumbed to the wreaking ball despite putting up a fight: Irving Gill's Dodge House (1914-1970) or Bertrand Goldberg's Prentice Hospital (1975-2013).

Two recent arrivals illustrate architecture's perilousness in relationship to public opinion – from the top down. President Trump recently took aim at the brutalist FBI Headquarters in Washington DC, calling for the J Edgar Hoover Building to be demolished and rebuilt.

Via a source, the website Axios quoted him as saying in a rant against the FBI: "Even the building is terrible. It's one of the brutalist-type buildings, you know, brutalist architecture. Honestly, I think it's one of the ugliest buildings in the city."

While, his aversion to the style is clearly stoked by the ongoing Mueller investigation, his judgment is out of step with a growing mainstream embrace of such concrete designs. Trump supporter Kanye West cites brutalism, as well as postmodernism a la Robert Venturi and Denise Scott Brown, as inspiration for his Yeezy Headquarters in Calabasas.

The La Jolla design represents a key part of the duo's oeuvre

And Venturi Scott Brown's addition to the Museum of Contemporary Art San Diego in La Jolla, California, is the second arrival. In late July 2018, a robust group of architects, curators, historians, and critics submitted a letter to Paul Jacobs, chairman of the museum board, and director and CEO Kathryn Kanjo as a plea to reconsider demolition of the VSB addition and stop the new expansion by Selldorf Architects.

The museum is currently closed for renovation and expansion, so it is hard to wager if public pressure will be enough to scuttle the Selldorf scheme. What isn't difficult to imagine is why a museum board might select the New York–based architect. Annabelle Selldorf's work is the embodiment of good taste.

As architect of the upcoming Frick Museum, the newly opened Swiss Institute, and gallery-cum-emporiums like Chelsea's David Zwirner and Hauser and Wirth in LA's Arts District, she caters to the aesthetic values of contemporary art market: pale and seamlessly connected to the flows of capital.

Selldorf's seeming ease in creating spaces of beauty and luxury is not so dissimilar from Gwyneth Paltrow's, who when profiled last week in the New York Times Magazine about her aspirational lifestyle brand GOOP said: "Our stuff is beautiful. The ingredients are beautiful. You can't get that at a lower price point. You can't make these things mass-market."

Is the signature big enough? The answer is yes

Venturi and Scott Brown have little interest in that kind of beauty – and its internalised narcissism. Their project grew out of a study of La Jolla's sleepy urbanism: beachy, low-key, and accessible. As the letter to MCASD La Jolla's top brass reads: "[the museum's] street frontage, museum store, and cafe extend the rhythm of Prospect Street's lively storefronts, celebrating the museum's location in the village commercial centre and drawing visitors toward the building."

One of the biggest ironies in the planned demolition is the MCASD La Jolla is not only landmarked, but that the museum's original building is the Ellen Browning Scripps House (1915) by architect Irving Gill. Gill's modernist designs – plain and rational where VSB's are enthusiastic – were subject to demolition threats throughout the second half of the 20th century. Critics like Ester McCoy routinely stood up to those developers and city planners who found his work boring or ugly.

In 1985, when the Torrance City Council was on the verge of erasing several of Gill's designs, she sent them a letter. "I hope that you may be stirred to some civic pride before you have razed all trace of the past to make way for parking lots," she wrote.

At 22 years old, VSB's design is a young addition to Ugly Valley. Although it is tempting to make a case for preservation based on the ongoing postmodern revival flourishing in design and fashion circles, the project was completed in 1996 and, as such, marks the tail end of the movement. (The discursive relevance of both PoMo and Decon faded by the end of the 1990s.) Late arrival, however, places the project at the preface of the museum boom. Lest we forget that the Guggenheim Bilbao opened in 1997.

It should be preserved. Taste be damned

Both too late and too early, the VSB design continues to look a bit dated. The colonnade proportions are slightly cartoonish and, even with neon rimming its rising arches, the museum lobby is unprepared for the kind of "architectural moments" that Frank Gehry's icon and, let's face it, Instagram now demand. But this is exactly why it should be preserved, not for any stylistic nostalgia. Taste be damned.

Here in Ugly Valley it seems too soon to digest the bloated mess that was 1990s architecture. Before computation took command, the decade saw the arrival of capital "D" design, the turn toward the post-critical, and the emergence of kind of homespun modernism that recently reemerged the at 2018 Venice Architecture Biennale, leaving Arsenale visitors to comment: "That was so, so... nineties."

Of course, the decade's truest offering was the rise of the star architect. And this last entry gives criteria for evaluating the call for preservation: is the signature big enough? The answer is yes. (VSB's National Gallery Sainsbury Wing in London was listed as a historic building with Grade I protection this past May by Historic England.)

While the La Jolla design may no longer suit present sensibilities, it represents a key part of the duo's oeuvre – a small piece worthy of study as tastes change over the decades. Venturi Scott Brown's addition should be saved from Ugly Valley because it is by Venturi Scott Brown.