A generation ago, the words 'historic preservation' conjured images of house museums and members of the D.A.R. raising money to save old so-and-so's family mansion, where Lincoln or Washington once slept. Not so, today. Now, the practice of historic preservation is far more democratic and ubiquitous, largely because many businesses and residents are returning to city centers. New uses are being imagined for old buildings, and not just fancy buildings.

About half of all commercial buildings in the U.S. were constructed before 1980, and over 90 percent of current housing stock was built before 1990. An architecture professor also told me a projection that 90 percent of U.S. construction in the next ten years would be on existing properties, not new buildings. What this means for readers is that adaptive new use is the go-to practice of almost any new company that wants to be located in an urban center. (My own office in downtown Savannah, Ga., occupies a 19th-century residence that later housed a law practice.)

This is good news, because the greenest building is one that already exists. And yet, this upcycling trend also presents a unique challenge: How do we take an historic building and make it feel purposefully contemporary and vibrant? And by historic, I mean any building more than 25-40 years old that is not being used for its original purpose.

In 1978, I founded the Savannah College of Art and Design, acquiring a gargantuan 19th century armory for our first academic and administrative building, and in the nearly 40 years since, the university's infrastructure around the world has grown to include a former power station, farmhouse, courthouse, jail, and train depot, among many other historic and formerly derelict properties. Why? Well, in most cases it was more efficient to adapt these abandoned properties than to build new ones.

In urban areas across the U.S., this same opportunity exists for other startups and companies, where empty schoolhouses, warehouses, retail spaces, residences, houses of worship, and other potential gems await a little elbow grease and imagination. If you're considering moving your company into an historic space, here are a few of my own secrets to help you make that old fire station or corner store new again.

Designers know the three tenets described by Vitruvius some two millennia ago: All great architecture exemplifies firmitas (strength), utilitas (utility), and venustas (delight). In my many years of preservation design work, I've added three additional principles to which I adhere: mutabilis (flexibility), ludere (playfulness), and mirandum (surprise).

First, flexibility. While it's important to know the history of the structure, there's no need to didactically adhere to its original purpose. For example, the balcony wrapping around a former church sanctuary may be enclosed with glass walls to create meeting rooms with a view. Or one might transform the sturdy support columns of a former warehouse into miniature ideation hubs with chalkboard paint or custom vertical whiteboards. Our intentional, sensitive adaptation of old structures to new purposes give the buildings the flexibility to endure.

Second, playfulness. There's no need to treat every historic structure with uptight reverence. Respect the integrity of the architectural heritage, but also bring a little life to a building others may have left for dead. Cover the floor of your waiting room with artificial turf and place a few old putters in an umbrella stand in the corner. Who wouldn't put down their iPhone for a little mini-golf? You think I'm kidding.

Third, surprise. Preservation design should provoke ideas and conversation—and the best way to engage with colleagues or clients in an historic space is through the compelling power of vibrant contemporary art. The incongruity of jazzy art placed in a sedate historic setting can wake up and generate ideas in guests and employees alike.

Old properties embody inherent mutability. The constraints of designing interiors for historic shells actually awaken a designer’s imagination. Be fearless, have fun, and give new life to forgotten architecture with a little playful irreverence. Who said reducing your company's carbon footprint had to be boring?