Sarah Castle

Yes, the fundamental function of buildings is to provide shelter—but that doesn’t mean they have to be a snooze. “There’s a great value in creating architecture that lifts spirits and brings joy,” says Sarah Castle. As co-founder and director of U.K. design firm If_Do, she has built her business around creating eye-catching, community-centered designs that transform urban areas otherwise filled with indistinguishable glass high rises.

One standout: her roller coaster-inspired Brent Cross Town Substation. Working in conjunction with artist Lakwena, Castle’s firm created what has become an undeniable London landmark—viewed every day by some 6 million people traveling to and fro by road and rail. Standing 21 meters (68.9 feet) at its highest point, the rainbow-hued structure wraps the eyesore electrical substation with undulating bands and triangle-shape panels to create a kaleidoscope effect.

“Here you have something that would typically be a really boring piece of infrastructure … but we’ve been given the opportunity to create something really special,” she says.

It’s not all flash, though. The project was built to include the inspirational statement: “Here we come, Here we rise and shine,” reflecting the studio’s “ambition to inspire and bring people together in the local community.”

Castle and her team want their structures to feel like an organic part of the neighborhood. When they first began work on a London community center project called The Yard, it was with the aim of “radical inclusivity”—meaningful engagement with the local community and young people in particular. A high bar in the best of times, but the If_Do team managed to pull it off entirely under pandemic restrictions—finding a way to gather input from 120 community members.

Castle believes in “the power of coming together to build something collectively,” she recently wrote on LinkedIn. And these kinds of projects only come to life by combining “diverse perspectives to workshop creative and innovative solutions, and to ensure the end result has in mind the specific needs, preferences and values of the community,” she explained.

Castle is equally passionate about “the need to make architecture a more diverse and equal profession” and is a founding member of Part W, a group that promotes gender equality in the built environment. To show the impact of female project leaders, for example, it created Women’s Work: London, a map highlighting building projects that were designed, built or supported by women.

The North Star for Castle? Architecture in public spaces can—and should—be about more than just creating buildings.

“Today, as we face numerous challenges, from climate change to social inequality,” she writes, “the role of active placemaking as a tool for addressing these issues has become more important than ever.”