Susan Miller-Havens in her temporary gallery at 9 JFK St., Harvard Square. (Photo: Jan Devereux via Twitter)

The visual arts have a Harvard Square patron of sorts in the developer Regency Centers, making for a small, temporary boom in gallery space: Susan Miller-Havens has opened a four-month residency at 9 JFK St., making for what’s believed to be the first solo artist gallery in the square, and perhaps Cambridge.

And Spaceus, the MIT grad startup that fills empty storefronts with enlivening public uses, has been granted 20 Brattle St. by Regency through Jan. 15; it’s using the space to host events such as weekend takeovers by a rotating crew of artists and a performance-art happening Oct. 27 for Arts Matter Day. (It also hosts other kinds of things, from office hours for vice mayor Jan Devereux to an “Empire Records” themed Halloween party, also Oct. 27.)

Both provide companionship for the Cambridge Artists’ Cooperative Gallery on Church Street for a moment the business association’s Denise Jillson calls “a flash of light in nearly barren art gallery landscape of Harvard Square.”

They’re smaller steps to keep the area lively before a big step that could depress tourism for much longer: a redevelopment in the heart of the square that promises to overlap with construction zones for the Out of Town News kiosk and surrounding plaza and, a block down on Church Street, the Harvard Square Theatre makeover. The combined projects means years of construction that threatens especially businesses relying on tourism and foot traffic.

Spaceus invites people into its 20 Brattle St. space, which hosts weekly Artist Takeover events – popups within a popup open through Jan. 15. (Photo: Spaceus)

Regency’s Abbot block project stands out for its direct effect on some two dozen mostly longtime Harvard Square office and retail renters – now down to 10, with Miller-Havens among them, as – being displaced by the work. The retail and office project (formerly called The Collection at Harvard Square under developer Equity One, now called The Abbot Buildings since Regency took over) remakes 1-7 JFK St. and neighboring buildings at 18-24 Brattle St. and 9-11 JFK St.

After Equity provoked a furor with the plan, Regency tried a slightly more humane phased approach and, in November, a prominent peace offering: an updated lease agreement that let The World’s Only Curious George Store stay in Harvard Square – first in its location at JFK and Brattle streets, then in another part of the building during construction. In July, Miller-Havens had displacement worries too, but by Sept. 14 a deal had been worked out for four months or longer at her existing rate. “It’s wonderful,” Miller-Havens said.

But Regency plans to start construction in early 2019, and when that signals the end of her time at 9 JFK St. ends, Miller-Havens isn’t sure what she’ll do.

Susan Miller-Havens’ art gallery welcomes a crowd to its Wednesday soft opening. the gallery will be at 9 JFK St. for four months or longer. (Photo: Miller-Havens Art)

The family that owned the building before Equity One kept rents low for small businesses, but with purchase and redevelopment costs to recoup it’s expected that “no one can afford space in Regency afterward,” Miller-Havens said, describing the uncertainty facing the 10 remaining tenants.

In the meantime, she hopes to not just display her “Now You See It Now You Don’t” exhibition, but to make her gallery available for arts groups and others as a meeting space, showing “what it’s like to have an art gallery in Harvard Square” as an argument for more patronage in the future.

“I don’t think that will influence Regency, but in New York there are developers who have built in art space at affordable rents,” she said. “Regency is not doing that.”

Spaceus is addressing the issue from a different angle, using its Harvard Square space for a daylong letter-writing event Oct. 26 called “Arts Matter,” where visitors will be asked to write about or create work about why the arts matter to them. The letters will be compiled and  presented at the next meeting of the Mayor’s Task Force to Support the Arts in Cambridge, which Mayor Marc McGovern said in June he was forming to “develop a set of recommendations that will enhance the arts in Cambridge in a lasting and sustainable way.”

Spaceus hasn’t confirmed where it might open after its time at 20 Brattle St., co-founder Stephanie Lee said, but it has a full roster of events there – Oct. 27 brings “Roco 1.0,” a multimedia installation performed in the round by the Philth Haus art collective, with what Lee describes as a sound performance, “intriguing materials and diamond dust” – and at 11 First St., East Cambridge, where a brief residency in a former Finagle a Bagel allows it to open an exhibition called “Feminism Prism” on Friday.

While Regency hasn’t committed to anything supporting the arts after construction, officials said in September through senior vice president Krista Di Iaconi that Miller-Havens and Spaceus had it “looking forward to being able to provide a more engaging and community-focused experience through art and culture.” A message was left Thursday to ask directly about the opportunities for Miller-Havens and others after construction.