When I saw the plywood boards go up on the façade of One Broadway (formerly Au Bon Pain) in the early Fall, I hoped — in vain, it turned out — that Yale Properties was taking measures to protect the structure during renovations. Instead, the building has been altered by a feeble cover-up job and currently sits empty.

I have no love lost for Au Bon Pain. I guess I never formed an attachment to the place. What I miss, however, is the original design of the storefront, which had been in place since 1943. The design’s elegance came from its simplicity. Situated at Broadway’s oblique intersection with York Street, the building’s unadorned and curving façade deftly rounded the corner. A thin green racing stripe, punctuated by short vertical hash marks, was its only embellishment. At eye-level, relief pilasters accented the building’s presence on the street and a curved glass foyer drew in passersby. One Broadway was a rare example in New Haven of the “Streamline Moderne” — a late type of art deco architecture that emerged in the 1930s — and a perfect fit for the building’s strategic position.

What’s wrong with the new façade? Too much brick, for one thing. A graceless 1920s garage might have inspired the design. The haphazard placement of its desultory uprights and the building’s uneven roofline create an awkward rhythm on the street that makes for an ungainly treatment of the corner. In short, One Broadway has lost its flow.

Do old buildings need to be modernized in order to stave off physical obsolescence? Absolutely. Like other parts of Yale’s physical plant, investment in the maintenance of retail properties should be applauded. The question is how to balance rehabilitation with continuity. One factor that positively contributes to the character of a place is a perceivable sense of diversity and evolution over time. Architectural heterogeneity — differences in scale, form, materials and signage — is one indication of the work of time on a commercial street and relates, as well, to its range of enterprises and activities. When a serviceable older storefront is sacrificed (when it might have been restored), some of that valuable and appealing urban patina is scoured away.

Over the course of the 1990s, Yale initiated a strategic effort to acquire and redevelop properties on Broadway and to refurbish its streetscape. The signature project, erected in 2001, was a large structure at 29 – 45 Broadway that took the place of several smaller buildings. Yale instructed architects to design three separate façades for the large steel-framed skeleton. One of the façades, Urban Outfitters, was rendered in a “modern” style, while the other two, the shoe store and J. Crew, were dressed in throwback styles of Italianate Neoclassical. It was a crafty move that broke down the building’s monumental scale, on the one hand, and endowed that stretch with a superficial sense of development over time.

It is difficult to invent the aura of a place that has accrued over a long period of time. My architectural critique is partly fueled by a sense of nostalgia for the businesses and proprietors of the Broadway district that have fled the scene. It is, for me, a personal ghost town populated by places like the Daily Café, the Yankee Doodle, Cutler’s Record Shop, Quality Wine, the Yale Co-op, Labyrinth Books and Whitlock’s Typewriter Repair Shop, among others — a few of which never overlapped in real time. Some of you will share these references; those that have known New Haven longer will recall a different array of people and places, and perhaps not always fondly.

Nostalgia does not pay the bills, however, and there will always be turnover in healthy retail districts. Each generation forms its own attachments. One day, undoubtedly, a group of Yale alumni will conjure memories of good times at “ABP.” Ultimately, buildings are most important for the establishments they house. Observers should take heed, therefore, when a single institution starts to make most of the decisions about the makeup of a retail district.

What can Yale do? Most importantly, Yale Properties can attract a tenant that will provide a useful service to students, faculty, staff and the community at large. One Broadway had been occupied for many years by a Liggett’s drug store (with very active signage). We can hope that something just as useful and interesting will take its place on Broadway. On the other hand, Yale should resist installing another apparel store. Enough is enough. There are advantages — for retailers and shoppers alike — to cultivating an agglomeration district of like enterprises. This does not apply, however, to a compact district like Broadway. The current imbalance toward clothiers on Broadway is unnecessary and, frankly, strange; the effect is the surreal and unpleasant sensation of walking through a stage-set outlet mall.

Elihu Rubin is the assistant professor of Architecture, Urbanism and American Studies and the co-director of the documentary film “On Broadway: A New Haven Streetscape.” Contact him at elihu.rubin@yale.edu.