Can Boston’s affordable housing shortage be eased?

They gathered outside the Fenway’s Burbank Garden Apartments one recent breezy morning to celebrate. Dignitaries lined up with praise and fanfare, and police closed a street to traffic.

But this was no ribbon-cutting — not even a groundbreaking ceremony. Officials, led by Mayor Martin J. Walsh, were celebrating the preservation of 52 affordable housing units.

“What’s going to happen today is residents are going to be protected from displacement,” Walsh told the crowd.

It was a small victory in one of City Hall’s toughest fights: keeping homes affordable for low- and middle-income residents. Advocates for affordable housing applaud the preservation of such units but are challenging the Walsh administration to do much more.

To those who are pushing for more affordable housing, any victory is crucial at a time that an influx of high-paying jobs in tech and other sectors has already begun to force low-income residents and their families, many from Boston’s minority communities, out of the housing market.

Boston’s population grew nearly 5 percent in the decade leading up to 2010, and another 9 percent through 2016. The city is projected to top 700,000 residents by 2030 — the most since the 1950s.

It is a boom that many cities would envy, but the growth has triggered a shortage of affordable housing that only threatens to worsen, posing a significant challenge to the winner of Tuesday’s mayoral election — whether Walsh wins another term or Councilor Tito Jackson scores an upset.

“More and more residents of Boston, as well as planners and officials, are aware that this is a crucial moment for the city in terms of preserving affordability, and thinking about housing equity going forward,” said Japonica Brown-Saracino, a sociology professor at Boston University who studies urban planning and gentrification.

Under Walsh, the city in 2014 set a goal to build 53,000 new units of housing by 2030 — “We are making sure we are a city for everyone,” he said at a recent debate.

Of the 22,000 units that have already been built or permitted under Walsh’s administration, 1,682 are restricted to low-income families, or households that make from $21,000 to $62,050 for a family of four. Another 4,062 are restricted to middle-income households, or families of four that make as much as $125,000.

(Households that make less than $21,700 typically receive federally subsidized housing.)

Of the 53,000 units planned by Walsh, 6,500 would be reserved for low-income family households.

Sheila A. Dillon, the city’s chief of housing and director of neighborhood development, acknowledged the need to develop more low-income housing, saying the city is doing what it can with limited resources. But she said the city needs a plan to house all income levels, as well, specifically moderate- and middle-income families. That, or newcomers in need of middle-income housing will take whatever low-income housing the market has left.

“We are building a lot of housing, for a whole range of incomes,” she said.

But housing advocates say more needs to be done to control a market that favors the luxury development of places like Millennium Tower over quality affordable housing in the city’s neighborhoods.

Housing advocates argue that too many of the new units are for people who can’t afford them. That does little to stem the displacement of residents, many from the city’s minority communities, in Boston’s outlying neighborhoods: East Boston, Roxbury, Jamaica Plain, and Dorchester.

“It takes a very intentional intervention,” said Helen Matthews, a housing advocate with City Life/Vida Urbana.

Those affected by displacement include Rita Alcaraz, a 56-year-old single mother — a personal care assistant who says she works 60-plus hours a week at two jobs, at $12 an hour. She had been living in her Roxbury home six years when she was told last year that the new landlord would be raising the rent to $1,350 a month, from $900.

“We told them that was too much for us, then they told us we had to go,” she said. “I’ve seen a lot of people who have left here . . . and I don’t want to leave. I want to live in my neighborhood.”

Socrates Guzman lived in the same Roxbury neighborhood for 30 years, in the same place for the last 10, yet he was told by new building owners last year that they would be spiking his rent — to $1,850 a month from $1,000.

“It kind of shocked me,” said Guzman, who works two jobs as a maintenance manager. “That was kind of telling me ‘I don’t want you here,’ because [they knew] I wouldn’t be able to afford it.”

The city has no way to count evictions. The Jim Brooks Stabilization Act — recently passed by the City Council and celebrated by the Walsh administration — would require landlords to notify the city if they move to evict a tenant, allowing it to track which landlords frequently evict tenants, and where. But that plan still needs the Legislature’s approval.

Housing advocates also pointed out that the council’s final version of the Stabilization Act was gutted of a provision that would force landlords to explain why they were evicting a tenant. The scaled-back version left Walsh’s newly created Office of Housing Stability with no authority to regulate evictions, though city officials say it would still allow them to monitor which landlords are evicting tenants the most. That way, the six full-time employees assigned to the Office of Housing Stability can reach out to tenants to alert them to their rights, and help them negotiate new leases.

“It is not a foolproof solution, but it is minimizing the pain,” said Dillon, who pushed for the Stabilization Act in its original form. “This administration doesn’t want to have anyone displaced . . . that’s what I’m working on.”

Dillon pointed to other measures Walsh has put before the Legislature, such as a proposal that tenants be entitled to a lawyer in Housing Court, and that tax credits be offered to landlords who keep rents below market rates, as well as a right of first refusal for tenants to purchase buildings that are offered for sale on the private market. But no action has been taken, and the measure does not appear to be high on the legislative agenda.

City officials embrace the development boom and the population surge, and the tax dollars they bring, though housing advocates question if that boom has been at the expense of residents of the outlying neighborhoods.

“They’re just giving the store away to large-scale developers,” said Michael Kane, a longtime community housing advocate.

Under an Inclusionary Development Policy enacted in 2000, developers who seek zoning relief or city land must contribute to the affordable housing stock, even if in limited ways. City policy requires that developers set aside 13 percent of a development — any housing with more than 10 units — as affordable to moderate- to middle-income households.

In 2015, the Walsh administration increased that requirement to 18 percent for any affordable housing that is built off-site of the original project, which many developers do. For instance, a developer who builds housing in the Seaport District could build the required affordable housing in a different neighborhood.

Alternatively, instead of building affordable units, developers can make a direct payment of 15 to 18 percent (depending on the neighborhood) of the project’s total cost to a city fund.

Brian Golden, director of the Boston Planning and Development Agency, said that percentage rate is meant to strike a balance, forcing developers to contribute to the affordable housing stock while still welcoming development and helping the city meet the demand.

“The goal was simply to get the highest numbers possible, without jeopardizing the development,” Golden said, noting the city plans to reexamine the rate in 2018. “You’ve got to have boundaries.”

But housing advocates say the city can demand more of developers, noting the boom that is already occurring. Cambridge recently increased its requirement to 20 percent, though it requires all affordable development to be onsite.

Walsh’s challenger, Jackson, said he would raise the rate to 25 percent.

He also proposed greater restrictions on developing city-owned land, so that is all classified as affordable.

Grass-roots groups — from tenant associations to ad hoc coalitions — have proposed a range of initiatives, such as taxing building owners who flip properties at a large profit or installing rent control. In 1994, the state’s voters outlawed rent-control laws in a referendum, though housing advocates say the city could seek limited ways to control year-to-year rent increases, or prevent rent spikes until apartments are vacated.

Walsh said during a recent debate that he opposed rent control. Jackson supported it.

Advocates said Boston could also propose “recapture agreements” that would allow the city to claim a percentage of a profit a developer sees from the quick resale of a development that needed the city’s approval. That proposal is based on reports a Swedish company, Skanska USA, sold a Seaport District luxury tower in 2015 for $450 million less than three years after developing it at a cost of roughly $150 million.

“Look up, look up and see how much the city’s physical environment has changed,” Kane said. “The effect is, it drives up rent for everybody else.”