Five oversize photographs hang inside architect Frank Lucas’ office and represent his half-century-long career and the work of one of the South’s largest and most influential firms.

That firm, LS3P & Associates Ltd., has employed hundreds of architects who have designed thousands of buildings across the Lowcountry, the Southeast and beyond.

It marked its 50th anniversary this month not with a gala but with an act of service. Architects from the firm’s six offices in North and South Carolina spread out to more than 50 schools to read aloud their collaborative effort, a children’s book named “Lucas the Beaver.”

Lucas took his copy to Mitchell Elementary School, where he attended school growing up and preferred drawing comic book characters over doing homework.

He has become one of the state’s most respected and honored architects of the past century, but he also has remained close to his roots. In some ways, he is the opposite of the stereotype of a successful architect: He has neither a big ego nor a funny set of glasses.

John Jacques, professor emeritus of architecture at Clemson University, has known Lucas for most of his professional career and said his influence extends beyond his designs and buildings.

“I guess I can’t say enough in praise of Frank and what he’s done for the profession, what he’s done for the community at large and what he continues to do to nurture younger architects as they make their way into the profession,” Jacques said.

The five buildings in the photos tell the story.

Gaillard Auditorium

Not long after graduating from Clemson and returning to his hometown, Lucas struck out on his own as soon as he passed his architectural exam in 1963.

“I thought I could make it,” he said. “Nobody was really doing contemporary work, that was the main thing. That’s what I was trained to do.”

A year later, Lucas teamed up with architect Sidney Stubbs to secure the commission to design the Rodenburg Supermarket at 635 Rutledge Ave. The young architects figured they could improve their chances by working together.

Their greatest collaboration, however, would come in their own time, over several frantic weeks, as they prepared their entry into the design contest for a new auditorium and exhibition hall on Calhoun Street.

They won the $1,500 prize, and they hit the civic club circuit to help then-Mayor Palmer Gaillard sell the project to the voters. That gave the young architects valuable exposure.

Lucas and Stubbs ended up designing the Gaillard Auditorium on a tight $3 million budget. The large medallion of the city seal was cast out of plastic instead of bronze to save money.

Adjusted for inflation, the city and private donors currently are spending more than seven times more to renovate it than it cost to build. Lucas and his wife, Edith, attended the last performance before the remodeling began, and it was a bittersweet moment.

“It served the city for almost 50 years,” he said.

Charleston Water System

Several other major commissions followed the Gaillard, including the Blue Cross tower outside Columbia, Grace United Methodist Church on Sam Rittenberg Boulevard and preservation work.

In the firm’s second decade, architect Thom Penney was hired. Now its president and CEO, Penney had been no stranger to the firm, having swept its floors and performed other odd jobs there in high school in hopes of being allowed to draw on occasion.

He designed a new headquarters for the Charleston Water System, then called the Commissioners of Public Works, on St. Philip between Vanderhorst and Warren streets.

While the building in some respects appeared as modern as the Gaillard, the design also made reference to the city’s tradition. Its concrete siding was textured to appear like clapboards. Lucas said some critics falsely accused the firm of building it in wood. Along St. Philip, the large office’s facade was broken into separate modules that referred to the rhythm of houses.

Lucas said the public wants buildings that strike a balance between the familiar and the new.

“The public still likes comfortable architecture,” he said. “We’ve become more comfortable harmonizing with what’s there.”

Charleston International Airport

Lucas said the firm has been faithful to a simple set of ideas throughout.

“We want to grow. We want to do quality work. We want to make some money,” he said. “All of those are equally important. And to have some fun.”

The airport was designed around the time that Lucas and Stubbs acquired new partners, Penney, Vito Pascullis and Richard Powell. By 1984, its name had changed for a fourth time into something that would stick through future comings, goings and mergers: LS3P.

The firm previously divided itself into studios, or groups of architects that could specialize in areas such as health care and education.

The airport also was something the firm’s architects were increasingly passing through, finding work in other faraway places such as New York, California, Florida, even the Azores off Portugal.

Piggly Wiggly headquarters

The handsome brick Piggly Wiggly headquarters building between Albemarle Road and the Herbert Fielding Connector hangs on Lucas’ wall but represents more than an office project. That’s because LS3P has designed more than 67 new buildings, expansions and renovations for the grocery chain.

To succeed and survive through three separate economic downturns the firm had to earn client’s respect for its work as well as its ability to stick to a budget.

“Good design is like starting with something and knowing when to quit taking things away,” Lucas said. “We’ve lost a lot of projects because we chose not to do what we knew was virtually impossible or fraught with problems.”

About 75 percent of the firm’s business has been repeat clients.

215 King St.

The final picture is home. The law firm Nexsen Pruet was looking to build its new law office on King Street just below Majestic Square at King and Market streets.

Lucas, who has been mostly involved in marketing and finding clients, helped come up with a solution with Nexsen Pruet realized it could not afford the entire site: The firm could have its offices in front, over a retail space, while LS3P’s new offices would be built behind.

The resulting building has a more traditional facade along King but a more adventurous design in back, with a red concrete wall piercing through a glass curtain wall.

Lucas also pointed out how it is recessed from an older brick warehouse, and how its windows offer that warehouse privacy. It’s a building that would make sense on no other site.

Jacques said the firm’s work is perhaps most notable for its careful analysis of what fits into a particular place. And both Majestic Square and 215 King represent this at its best.

“Architects love to talk about the relationship of place,” he said. “Sometimes we get it and sometimes we don’t, but in their case, they get it more often than not.”