The third wave of gentrification is just now being felt in Long Island City,Queens. Artists and other creative types colonized the area’s warehouses several decades ago, followed by a burst of high-rise development aimed at singles and couples who wanted a lower-cost alternative to Manhattan.

Now apartments that can accommodate families are in demand, and buildings on the drawing board or under construction will have playrooms as amenities, along with gyms and rooftop spaces, area brokers say.

“We’re just seeing the infancy, no pun intended,” said David J. Maundrell, the president of brokerage, which has many listings in the area. “By the time the child is ready for preschool, there will be many options for them, and they can grow and stay in the community for 10 years.”

Families living in Long Island City now laud the neighborhood’s new waterfront parks, its relative affordability and a congenial sense of community that, they say, makes the area feel like a suburban extension of New York City.

But Long Island City’s location remains a chief draw. “The fact that we both work in the city was a key reason we moved to L.I.C.,” said Jackie Freund, a mother of two who came to the neighborhood eight years ago when she and her husband, Lee, began thinking about having children. “We didn’t want to commute over 45 minutes each way and lose precious time with our family.”

A short commute is also attractive for parents who want to keep their children enrolled in Manhattan or Brooklyn schools.

In the first quarter of last year, said Jonathan J. Miller of the appraisal company Miller Samuel, the average size of units sold was 822 square feet. In the fourth quarter it was 1,364 square feet. Mr. Miller cautioned against seeing the figure as a long-term trend, but Eric Benaim, the president of the brokerage firm Modern Spaces NYC, said about 40 percent of his clients were seeking two-bedroom or larger units. “In most of those cases,” he said, “they are families.”

Among the new buildings, the 122-unit L Haus, at 11-02 49th Avenue, offers three-bedroom condos as big as 1,800 square feet, along with a 10,000-square-foot yard; it is over 60 percent sold. A 157-unit rental complex at 17-19 27th Street, scheduled to open later this year, will have a playroom.

With few three-bedroom apartments available to rent, two-bedrooms are in high demand. According to market reports from the brokerage MNS, two-bedrooms saw the largest rent increases in Long Island City over the last two years.

Parents say the area still lacks conveniences geared toward families. The 7 subway line can be finicky, they say, and Food Cellar & Co., the area’s main grocery, is more a high-end than a day-to-day kind of store.

“We need more services,” said Catalina Villamizar, who moved to the area from Midtown when she became pregnant with her now 3-year-old son. “More day care, places to get a kid’s haircut, doctors, all that kind of stuff.”

Anticipating growth, public and private schools are expanding. Public School 78Q plans a new facility for kindergarten through Grade 5, and Les Enfants Montessori School in Long Island City has expanded its space to accommodate 100 more students. There are also plans for a new high school, and a 22,000-square-foot waterfront library is scheduled to open in 2013.

Ilana Angeliades, the director of Lolly’s Learning Center, a preschool for 2- to 5-year-olds, says that her program is at full capacity, and that parents have even taken to calling before their children are born. In December, in response to a demand for infant care, Ms. Angeliades and Natasha Parmar openedBrighter Babies, for children as young as 3 months old.

Yet despite the presence of more strollers on the streets and expectant mothers in restaurants, Long Island City is no Park Slope, said Dan Miner, the senior vice president of the Long Island City Partnership, an economic development group.

“Park Slope has been a mature residential neighborhood for 100 years,” Mr. Miner said. “Long Island City is progressing along at its own course.”