Walk a block south or west and construction crews hammer away, turning relics from the city's industrial past into soon-to-open art spaces.

“There is a groundswell happening right now,” said Susan Halter, executive director of the Cultural Organization of Lowell and the city’s cultural affairs office. “This feels like Boston 20 years ago.”

Or perhaps, Brooklyn five years ago.

Long the butt of many jokes (see “The Fighter”), this hard-scrabble mill town is riding a wave of reinvention led by a steady stream of artists and a string of new galleries and venues that have opened recently to showcase their talents.

“This is need-based,” said Lindsey Parker, co­director of Uncharted Studios and Gallery, a youthful art collective settling into a highly visible storefront on Merrimack Street.

Upstairs, 24 artists, writers, and filmmakers work in threadbare studios that rent for $75 to $250 a month. The median age is 27.

One of them is Parker, who instead of lighting out for New York to “follow the herd,” decided to “build a gallery in a place that needed one.”

Running a gallery at 24 “is seriously a dream,” said the sandy-haired printmaker, who recently graduated from Montserrat College of Art in Beverly.

That free-wheeling, anything’s possible spirit is what lured Alan Nidle and Karen Boutet to open the Zeitgeist Gallery around the corner.

Reinventing their bohemian Cambridge outpost that closed in the mid-2000s into a sprawling storefront on Market Street for the same price they would pay for a tiny spot in Inman Square was hard to resist.

The couple, who have ties to the area because Boutet grew up here, feel they have arrived right on time. “If you want to really ride the wave, you have to wait till it’s cresting,” said Nidle, who has a reputation as an iconoclast.

In the ’80s he transformed an ATM booth in Cambridge into a studio apartment and invited homeless people to spend the night. “I enjoy being on the fringe where I can be gloriously different,” said Nidle.

Both the Zeitgeist and Uncharted usher in new urban energy to the city’s downtown art scene that is raring for renewal.

“We are starting to reach critical mass. Nobody is going away,” said Maxine Farkas, who as the director of Western Avenue Studios has witnessed the change firsthand.

The mill-turned-art-complex that opened in 2005 with 31 studios will reach 300 by year's end. Recently owner Karl Frey continued the conversion to include Western Avenue Lofts: 50 artist live/work apartments that rent for an average of 94 cents a square foot.

“People walk in and fall in love with the space,” said Farkas, who was one of the first to move into a one-room loft with concrete floors and communal slop sinks in June.

Located in an industrial cul-de-sac, just beyond the city’s newly sketched cultural district, Western Avenue Studios has been a creative beacon for years. Now that the downtown is waking up with artist-established galleries, the bootstrap ethic (“If we can’t get commercial galleries to come to Lowell, we will start our own”) is stronger than ever, said Farkas.

It’s that do-it-yourself attitude that’s made artists like Michael Dailey Jr. jump in with both feet. “It’s not uppity. That’s the best part. People are willing to collaborate and are open to new ideas. It doesn’t feel so establishment,” said Dailey, co­director of Uncharted.

That Uncharted Gallery opened in July with a five-band blowout featuring groups from Northampton and Brooklyn on the city’s main thoroughfare, instead of off the beaten track, is significant.

“It’s exciting that these people were able to crack the downtown,” said Walter Wright, cofounder of the 119 Gallery, about a mile from the city’s core. Wright, an arbiter of the avant-garde, and his wife, Mary Ann Kearns, scoured derelict buildings downtown for years before opening their Lower Highlands gallery in 2005.

Part of what’s driving the downtown renaissance is landlords and developers who finally seem to understand what artists want: affordable places to create. Marshall Field, owner of the Wyman’s Exchange building, is a perfect example.

He struggled for years to find someone to move into the fifth floor when Lahey Eye Clinic moved out. Five years later, he found Uncharted.