The Montauk Library is preparing for its first expansion and renovation since construction of its current building in 1991. The $7.5 million project, which must be approved by voters, would give the library another 5,000 square feet of space, but increase its footprint by less than 1,600 square feet. The rest would be gained by filling in most of the double-height interior areas. A one-story addition with a basement is planned for the northeast side of the building and is to include a new entry that would also house a local history and fishermen’s center with gallery space. The library plans to triple the space allocated for children, to create a new area for teens, and to reorganize its mezzanine level to include a cafe counter, an outside terrace with an ocean view, and a quiet study area. At the basement level, the library is looking to expand its archival room, meeting room, bathrooms, and storage area.“Back in the day, the library was the keeper of the books,” Denise DiPaolo, the library’s director, said on Friday. “In the ’90s that’s what libraries were built for, but times have changed, library services have changed, and we do more than books. Books are not 100 percent of what we do; they’re maybe 25 percent of what we do, because we’re now here as a community center, and we are providing services and programs, entertainment, a place for social gathering, engaging, and we’re more of a physical place than a place to shush and check out books.” In just the five years between 2013 and 2018, according to Ms. DiPaolo, visits to the library increased by 21 percent and circulation increased by 22 percent. During that period, the library increased its adult programming by 137 percent and saw attendance in those programs increase by 39 percent. Its children’s programming increased by 139 percent, with 100 programs offered in 2013 and 239 in 2018, but attendance in those programs increased by 346 percent. And yet “the children’s department is so small that when families come in, there’s no place for adults to sit when the parents are there with their young children,” Ms. DiPaolo said. Looking at that usage data and seeing how cramped the children’s area is, the library board opted for a radical reorganization of the library’s main floor.A narrow children’s area now runs the southwestern length of the building, tucked off to the side of the main floor. Upon the addition’s completion, the bulk of the existing first-floor space would be devoted to children and teens. The current children’s room is to become a children’s programming room. “Now everybody’s vying for the same space” — the community room — “and the children’s programs are sometimes messy,” Ms. DiPaolo said. “There’s sparkles and there’s glue.” Having a dedicated space for children’s craft workshops and play programs and cooking classes “will make the community room cleaner and available for more adult programs.”The main-floor space now used for nonfiction and reference would become part of the larger children’s space that is planned to include a play area. It would open onto a walled exterior terrace for additional outdoor children’s programs. “In good weather we can have story time out there, children’s puppet shows,” Ms. DiPaolo said.An enclosed teen area would also be on the main floor. And there would be a dedicated children’s bathroom.Patrons would enter the library through a 1,150-square-foot addition, which is to house the local history and fishermen’s center, the circulation desk, and a new bathroom. “We’ve heard from the public that they’d really like to have a place to exhibit the rich fishing history of Montauk, and we feel we’re the place to do it,” said Ms. DiPaolo, who described “a technology center that pays tribute to the history of Montauk.”Stairs to the second level would be in a small addition on the northwest side of the building. Filling in most of the open mezzanine on the second story would not only give the library more usable floor area, it would improve acoustics in the library as a whole. “Back in 1990, when this was a quiet library where people came to just read, it was fine, but now we are a social place, we are a joyful place, and people come to the library with enthusiasm and something to share and we are louder than we were in 1990, and that’s okay because this is a lively place for people to gather, but the sound travels and there may be somebody upstairs who is having a test being proctored or they are working on a project, but the sound from the lower level and the main level travels all the way upstairs,” Ms. DiPaolo said. Adult fiction, nonfiction, and periodicals are to be housed on the second level, which would continue to be accessible via elevator. There would be a cafe service counter in the periodicals area. The level would open onto a new ocean-view terrace on the southwest side of the building, allowing patrons even more space to take in what might be one of the best views offered by any library on the East Coast. The northeast side of the building would feature a landscaped roof terrace that the director described a “High Line type of garden,” referring to the park created on an abandoned elevated railway line on New York’s West Side.New basement space below the entryway addition would allow the library to expand its archival storage beyond the tiny room it now occupies and provide much-needed storage space. Bathrooms in the basement, where the library’s community room is now, would be replaced with ones that are accessible to the disabled. All areas of the library would be made accessible as part of the renovation, and sprinkler systems would be added throughout.The project also includes a number of energy-efficient and environmentally conscious features, among them solar panels, vertical axis wind turbines, stormwater collection for irrigation, and a low-nitrogen septic system. The plan grew out of a series of surveys, needs-assessment interviews, and focus groups, Ms. DiPaolo explained. Patrons had great things to say about the staff, the ocean views, the concerts, children’s programming, and the library’s local history collection, but they were critical of the noise, the small children’s space, the lack of a teen room, and the fact that much of the library was not wheelchair-accessible. Responses confirmed much of what the library board already knew.Ray Beeler of Gallin Beeler Design Studio was the architect for the project and also designed the original building. “We didn’t need to familiarize him with the way this building functions,” Ms. DiPaolo said. “He knows it all; he’s got it all in his files.” The library would float a 20-year bond for the project, with a bond vote to take place at the Montauk School on May 21 from 2 to 8 p.m., the same day as the school budget vote and board elections. (The library and school district boundaries are the same.) Bond service is expected to cost the average taxpayer about $6.67 a month, or just over $80 a year, according to a release from the library.Architectural plans and renderings and details about the project in English and Spanish can be found on the library’s website. Library officials will discuss the proposal with residents and take public comments at meetings on Sunday at 1 p.m., Monday at 6 p.m., April 27 at 1 p.m., May 1 at noon, May 7 at 3:30 p.m., and May 15 at 10 a.m. Ms. DiPaolo is also meeting with all manner of community groups and organizations, from the Montauk Chamber of Commerce to the Montauk chapter of AARP.