America’s Test Kitchen has the most-watched instructional television cooking show in the United States and a basket full of bestselling books. But you wouldn’t know it from the look of its headquarters, a small, unmarked multistory maze of offices and kitchens housed on Station Street in Brookline, Mass. All of that will change when the company moves to Boston’s vibrant Seaport District in September.

“We need the elbow room to create content across all kinds of platforms,” said Jack Bishop, ATK’s chief creative officer. “You can’t do books anymore without trailers and video content to support those books, for example. We’re going to have dedicated spaces so that we can separate some of our operations. It’s super exciting.”

The office move caps a period of transition at ATK, including the introduction of two new hosts for the company’s America’s Test Kitchen and Cook’s Country shows. Longtime personalities Bridget Lancaster and Julia Collin Davison took center stage after the departure of cofounder Christopher Kimball in 2015. Their debut season as hosts of America’s Test Kitchen aired in January, and ratings were slightly up from previous seasons.

“People really embraced Bridget and Julia,” said editorial director Elizabeth Carduff. In late October, the company will put out Cooking at Home with Bridget & Julia, an illustrated hardcover volume that includes 150 of the hosts’ favorite recipes from the ATK archives. Each recipe will be accompanied by short personal comments from the pair.

The release coincides with ATK’s sponsorship of Boston Eats, a celebration that will welcome visitors into the company’s new 15,000-sq.-ft. space, October 27–28. Visitors will be able to tour studios and test kitchens, try recipes from the kitchen’s new food truck, and meet the hosts, cooks, and authors. The event will kick off a multicity book tour of PBS stations by Lancaster and Davison.

This year also marks the 10th anniversary of the Cook’s Country television show. A companion volume, The Complete Cook’s Country TV Show Cookbook, 10th Anniversary Edition, will be released in late August, introducing readers to new personalities who will join Lancaster and Davison on the program.

ATK started in 1993 with Bishop, Kimball, and around 20 other employees. In April 2015, CEO and chairman David Nussbaum came on board from F + W Media. Since his arrival, ATK has grown from 185 employees to more than 200, with Sara Domville, one of Nussbaum’s former colleagues at F + W, coming on as chief revenue officer earlier this year.

ATK’s recipe development process is expensive and labor-intensive, and Carduff’s book division employs 13 people in the kitchen, seven editors, and seven designers to produce 13–14 books annually. Bishop said the new initiatives reflect ATK’s belief that “there’s an opportunity for us to continue to grow the book business.”

Over the past eight years, much of ATK’s growth has come from a focus on greater retail sales. “Books target people who are cooking but may not be watching public television,” Bishop said. In late September, ATK will reach out to those readers by publishing two thematic unjacketed hardcovers featuring existing recipes in affordable volumes: All-Time Best Sunday Suppers and All-Time Best Holiday Entertaining. The publisher’s first cookie book is in the works as well, and another of its successful slow-cooker books will hit shelves the same week that Cooking at Home debuts.

With all the changes in the works, Carduff is excited. “It’s a sea change, but the integrity of the books is the same,” she said. “We’re cooking and making books.”