But the city, which shares a border with the Bronx, has an enviable location, said Sam Mermelstein, a founding member of Enclave Equities, a development firm active there. About 30 minutes from Grand Central Terminal by way of the Metro-North commuter railroad, Mount Vernon is closer to Midtown Manhattan than many Brooklyn neighborhoods.
Enclave is at work on a five-building, 179-unit residential rental project on former industrial property near the Fleetwood station that will offer Manhattan-style extras like rooftop terraces and gyms. And, in a break with recent nearby projects, the $48 million development, set to open next year, will offer all market-rate units.
The rents for its one-bedrooms will be about $1,700 a month, which is less than half of what new-construction units cost in Lower Manhattan, according to online ads. “It makes no sense that this area is not booming,” Mr. Mermelstein said.
One complaint from Mr. Mermelstein and others is that Mount Vernon’s retail corridors, packed with discount clothing stores, nail salons and takeout restaurants, could use more variety.
One new option this fall will be the Mount Vernon Brewery, which will serve beers made on-site, as well as upscale pub food, in a brick 250-seat building where fake Christmas trees were once manufactured. The restaurant, across the street from the Mount Vernon East train station, one of three Metro-North stops in the city, will open this fall, according to Steve Nallen, one of the brewery’s co-owners.
Mr. Nallen has also bought a building across town, a low-slung former veterinary clinic a few steps from the Mount Vernon West station, where on a bleak stretch he plans to open a combination deli, beer store and bar.
“We saw a void,” said Mr. Nallen, who grew up in the Bronx. He initially sought to open his business there, but after searching for years, he could not find an affordable site.
Other projects are in various stages of planning. Around the corner from the planned deli, the firm Macquesten Development has proposed a 17-story tower with 189 mostly market-rate units on the former site of a gas station, according to company officials. The company also plans to raze the train station next door, which it already owns, and replace it with a more contemporary version with stores, the officials said. But both plans still require approvals.
Developers credit local leaders for helping push the changes. In Mount Vernon, for example, Mayor Richard Thomas compressed the time it takes to get a building permitting; a process that could sometimes take years can now take as little as 65 days.
In New Rochelle, a city of about 80,000, pro-development leadership also seems to be helping redevelopment efforts. In December 2015, the city, which sits on the Long Island Sound, rezoned 279 acres, including most of its commercial areas, to encourage taller construction.
The loftiest structure had been a 40-story rental tower built by AvalonBay Communities in 2007 in an earlier attempt at reinventing the city. And AvalonBay had to get special permission to go that high, said Luiz Aragon, the city’s commissioner of development.
Now, though, in the area by a Metro-North station, a developer can build up to 40 stories without any signoffs, and even go an additional eight stories in exchange for certain community-serving amenities, Mr. Aragon said.
Since those rules were changed, 13 projects, with 1,633 apartments and 115,000 square feet of commercial and retail space, have been approved for the downtown, he added.
RXR Realty, a development company based on Long Island, is one of the companies involved. In exchange for drafting the rezoning plan for New Rochelle, which will allow for 12 million square feet of development, RXR won exclusive rights to build on seven parking lots across city.
In late July, RXR announced its first plan to develop one of those sites, a rust-flecked two-level parking structure, which would give way to a pair of gleaming 28-story towers with up to 700 apartments.
Although the project, which would also add 40,000 square feet of shops, still requires approvals, the groundbreaking is planned for next year.
Separately, RXR is part of a team that is now building a 28-story, 280-unit rental tower on Main Street. The project, which also involves Brause Realty and ABS Partners Real Estate, will include 15,000 square feet of stores and a 10,000-square-foot theater.