Brooklyn residents know Pintchik’s Hardware, which has been on the corner of Flatbush Avenue and Bergen Street since 1940, for the quirky messages on its scrolling digital sign, its free cappuccinos, and the life-size fiberglass cow outside its entrance. What they don’t know is the Pintchik family is sitting on as much as $100 million of developable property and air rights, according to some brokers’ estimates.

Nathan Pintchik, the grandfather of the current president of Pintchik Inc., began the company in 1912 as a series of paint and hardware stores across the city, but over the years the family also quietly began acquiring dozens of buildings, especially on the stretch of Flatbush Avenue between Atlantic Avenue and Grand Army Plaza.

Now, with an estimated $3 billion worth of development pouring into parts of Flatbush Avenue to the north of the Pintchik holdings — in addition to the $4 billion Atlantic Yards project, which will create more than 6,000 apartments in Brooklyn — the time has come to begin redeveloping the properties, the current president of the family business, Michael Pintchik, 56, said.

The Pintchiks’ holdings are in a critical area, where several neighborhoods come together, an executive vice president at the brokerage firm Robert K. Futterman & Associates, David Rosenberg, said.

“It is a void in the center that will get filled in with new retail and tie everything in downtown Brooklyn, Fort Greene, Prospect Heights, and Park Slope together,” he said.

The family “really is a great dynasty” in the world of Brooklyn real estate, an executive managing director of Massey Knakal, Timothy King, said. “This was a place people were fleeing from in the 1970s, but they maintained their stand and even increased it. Now it is paying off.”

Mr. Pintchik said his father, Jack, dreamed of changing the “lackluster” avenue of furniture stores and hair salons into a boulevard worthy of Brooklyn.

“I was sitting beside him in the car when I was 6 or 7 years old,” Mr. Pintchik said. “We were driving down Flatbush Avenue and he looked out the window and said, ‘One day something great is going to be built here.'”

The first phase of the Pintchiks’ plans for Flatbush Avenue is to change the kinds of retail outlet that fill their buildings, and to construct rooftop additions and other expansions to create space for new apartments.

The second is the construction of as many as four new, mixed-use buildings on the sites of small commercial properties and lots along the avenue over the next three to four years.

The Pintchiks hope to lease their storefronts along Flatbush Avenue to local boutiques of the type found along Fifth and Seventh avenues in Park Slope and Cobble Hill, as well as to national tenants and even a big-box retailer, such as Crate & Barrel or Whole Foods Market, Mr. Pintchik said. The family is planning a 22,000-square-foot retail space at one of the new buildings planned for Flatbush Avenue and Sterling Place, which could hold a large national tenant. “We’re in the fortuitous position of being able to hold out for people we really want to come in,” he said.

Some of the changes are already in the works, Mr. Pintchik said.

Across the street from Pintchik’s Hardware, he recently signed up an Aveda spa, and many of his tenants along a section of Bergen Street near Flatbush Avenue have become more upscale. Ground floor offices have been replaced with a clothing store for pregnant women, Bump; an organic café, Organic Heights, and a high-end men’s clothing store, Private Stock. Two Manhattan restaurateurs telephoned last week about setting something up at one of the Pintchiks’ corner locations, he said.

Activity in the area has picked up dramatically as a result of the Atlantic Yards development just to the north. Mr. Pintchik said he received 15 calls last week about one site in front of what is planned to be the new home of the Nets basketball team, Barclay Stadium.

“In all my years over here, I’ve never received 15 calls in a week,” Mr. Pintchik said, adding that he sold three buildings to Forest City Ratner, which is developing the Atlantic Yards project. Property records show that the company received about $4 million for the properties, at 185, 189, and 193 Flatbush Ave.

The family company, Pintchik Inc., also has been able to command high rents for its renovated apartments. A one-bedroom apartment at the family’s building at 477 Bergen St. is listed with Corcoran Group for $2,575, and a past listing at 471 Bergen St. for a two-bedroom apartment was $2,975. Mr. Pintchik said a three-bedroom apartment at 192 Bergen St. is now on the market for $3,800 a month.

“A few years ago, we were getting probably 30% less,” he said. The sites for the new buildings are at 162-170 Flatbush Ave., 250-258 Flatbush Ave., 342-354 Flatbush Ave., and possibly another building nearby on Bergen Street, Mr. Pintchik said. Preliminary plans have already been drawn up for the buildings, which he said would be designed in a “seaport cast-iron” and “great brick” style.

“They will not be modern buildings,” he said. “They will be crisp, with great light and air, but fitting the neighborhood.”

The executive director of the North Flatbush Avenue Business Improvement District, Dawn Torres, said the family is the most constant thing about the neighborhood.

“The family has been in the neighborhood longer than anybody,” Ms. Torres said. “The store is like an anchor.”

The Brooklyn-based author Jonathan Safran Foer was, for a time, the personality behind the oracular pronouncements on the scrolling ticker. Visitors to the store can sing karaoke for prizes or sip free cappuccinos as they browse the expansive hardware and paint selection.

The family also is known for philanthropy. After paramedics revived Jack Pintchik, after he suffered a heart attack, he began a lifelong dedication to rescue workers. He helped found and fund the EMS Awards Ceremony to recognize paramedics who perform extraordinary service, and the fire department annually awards a Jack Pintchik Life Saving Medal.

Mr. Pintchik’s brother and the vice president of the company, Matthew, founded the Park Slope Volunteer Ambulance Corps., and Pintchik Inc. donated the first ambulance.