Elevator doors open. And there they are — Stacy, Clinton and even Randy, cast members from TLC’s “What Not to Wear” and “Say Yes to the Dress,” gazing out from life-size murals adorning the walls of the cable network’s offices.

At every turn of the sixth-floor digs in the headquarters of parent company Discovery Communications, TLC’s reality-show stars greet you.

Even the furniture in the waiting area — cupcake-shaped chairs tucked into a cake stand table — is a nod to Washington’s sibling bakers and Jersey’s pastry chieftain whose antics have gained a following for “D.C. Cupcakes” and “Cake Boss,” respectively.

Every colorful quirk of the decor reflects the network’s dedicated exploration of eccentricity. TLC revels in documenting everyday people living life, no matter how bizarre or mundane.

It’s a Wednesday morning in Silver Spring, and Eileen O’Neill, president of TLC and Discovery networks, is ready to talk about vision. She makes her way into the conference room, where general manager Amy Winter is already seated.

Winter is the young, urbane optimist, O’Neill the thoughtful pragmatist. They epitomize TLC’s target audience: women intrigued by the world around them.

“Whether it’s something as controversial as polygamy or as amenable as a baker’s shop, the aim is for the audience to come away with something of value and interest,” O’Neill said when asked about TLC’s programming goals.

What separates TLC from other networks, Winter chimes in, is its “compelling characters” who “tell their stories in a very openhearted way.” Audiences tune in for the authenticity of those stories, for the reality.

Reality TV is at the heart of TLC’s formula, as it is with much of cable television’s, but a sea change may be occurring: Competing networks such as Bravo and History are turning to scripted programming to appeal to an increasingly fragmented audience and to attract ad dollars.

Broadcast networks have long aired original scripted series, while cable channels were subsisting off reruns, documentaries and old movies. Many cable execs found the cost of producing scripted shows prohibitive, yet a few gave it a shot, with mixed results.

The popularity of cheaply produced reality shows gave cable channels little reason to diversify their lineup. But the enduring success of scripted shows such as “Mad Men” on AMC is encouraging more networks to venture into the format.

Wading into scripted programming might be the next logical step in TLC’s evolution.

TLC launched in 1980 as The Learning Channel. One of its early successes was the 1997 docu-reality series “Trauma: Life in the E.R.,” which followed doctors and nurses in emergency rooms across the country. In its seven seasons, it was nominated for four Emmys.

“It became a catalyst for a fair amount of demographic change,” said John Ford, TLC’s first head of programming. “It skewed female, which really caught us by surprise. We weren’t as sophisticated in understanding the gender dynamics back then but learned a lot about our audiences.”

What TLC execs learned was how to capi­tal­ize on viewers’ fascination with following people as they got married, had a baby, endured a makeover — lived life. This spawned “A Wedding Story,” “A Baby Story,” “What Not to Wear” and others.

These reality shows ran throughout the day, building TLC’s brand as the channel for “life unscripted” — the network’s slogan in the early 2000s.

When Discovery purchased TLC in 1991, the network was airing a mix of self-help shows, reaching roughly 15 million households and producing $13 million in revenue.

Figuring out what works

By 2001, Discovery had turned the network into a $367 million operation that reached nearly 80 million homes, according to media research company SNL Kagan.

TLC’s next big hit, “Trading Spaces,” which launched in 2000, lured viewers with the unpredictability of people’s reactions to home makeovers led by their neighbors. The show, averaging 4 million viewers, helped catapult TLC into the ranks of the top 10 cable networks.

But by 2005, the show’s fifth season, “Trading Spaces” had lost about 40 percent of its audience and TLC had lost its luster. Washington Post TV critic Lisa de Moraes said, “The show was a victim of its own success, as TLC cloned it and other networks jumped on the makeover bandwagon.”

TLC’s popularity flat-lined for the next few years.

“After the ‘Trading Spaces’ heyday, we started evolving The Learning Channel concept into a live-and-learn kind of thing,” Winter said. “We realized that people don’t mind learning, but they don’t want to be taught. We had a lot of experts on the air but shifted that to people whose life experiences have turned them into an expert.”

Winter pointed to the docu-series “Jon & Kate Plus 8” as an example of average people whose experience in raising eight children made them “a kind of expert in parenting.”

“Jon & Kate,” which debuted on TLC in 2007, became a ratings powerhouse, drawing 10.6 million viewers at one point, when the couple’s marriage fell apart two years later.

Critics lambasted TLC for profiting from the family’s troubles.

O’Neill, who was instrumental in developing “Jon & Kate,” acknowledged that it was difficult deciding whether to proceed with the show in the midst of the divorce. Yet the decision came down to what the family wanted to do.

“They always had the opportunity to stop,” she said.

Setting a tone

In many ways, “Jon & Kate” set today’s tone at TLC. During the show’s five seasons — it was canceled last year — the network rolled out a string of family-centric docu-series, including “19 Kids & Counting” and “Sister Wives.” Each show delved into atypical families.

“Because there are so many media outlets, they needed to find a niche,” said Patricia A. Williamson, a professor in the School of Broadcast and Cinematic Arts at Central Michigan University. “TLC has reinvented itself so many times but seems to have found its stride.”

In reinventing itself, TLC has come under fire for airing shows such as “Toddlers & Tiaras” and “My Big Fat Gypsy Wedding” that critics say are voyeuristic and border on exploitation.

“Those are worlds that exist with or without our camera there,” O’Neill said. “We’re not in the business of disrupting people’s lives. We approach all of our productions as partnerships, so there is a lot of healthy back and forth between our producers and our talent.”

Winter says the full spectrum of TLC’s lineup is “in sync with what our audience expects from us.”

Many of TLC’s competitors have embraced a similar view of building their schedules around common themes that in some ways speak to a brand identity. Bravo is where you go for fashion, food and to gawk at women with too much time and money. We TV is where you head to see over-indulged brides behaving badly.

Williamson says networks with heavy concentrations in that type of format are challenged to keep it fresh.

“With some of these docu-reality series, they’ll be hits for a season or two and start to wane in popularity,” she said. “It seems that TLC has realized that and has been cycling through new ideas.”

Still, being known for a type of programming doesn’t preclude cable networks from branching out into new formats. And they may have no choice but to diversify to remain competitive.

Change or die?

As much as viewers eat up reality shows, their appetite for well-executed, scripted shows is just as voracious. AMC proved that with the success of such original series as “Mad Men” and “Breaking Bad.”

“AMC has been on a tear for original-scripted programming,” said Noah Everist, associate director of media investments at ad agency Campbell Mithun.

AMC’s slate of top-rated series such as “The Walking Dead” delivered a 30 percent increase in advertising revenue in the first three months of the year.

“High-quality scripted shows are always in high demand from advertisers,” said Todd Gordon, executive vice president and U.S. director at MagnaGlobal, an advertising firm.

Brands enjoy the cachet of being tied to premium programming and the audience it delivers. Still, advertisers essentially chase ratings and will hitch their wagons to any show that can deliver numbers.

“Top-rated reality shows like ‘American Idol’ and ‘Survivor’ are among the most desirable places to advertise,” Gordon said, “but in general there is more demand for scripted programming.”

As a result, more cable networks are testing the waters.

The History channel made its foray into original scripted programming with “Hatfields & McCoys,” a miniseries that averaged 14 million viewers across its three-night run starting on Memorial Day. The historical drama about warring families set a new record as the highest-rated entertainment show on ad-supported basic cable, according to Nielsen.

History, known for documentaries and reality series such as “Pawn Stars,” is slowly diversifying its lineup. Plans call for History’s first full-scripted drama, “Vikings,” to hit the air next year.

“History has an uber-arching theme. When you go there, you have a frame of reference for what you’re going into. If you’ve already bought into ‘Hatfields & McCoys,’ you’re likely to stick around for the next show. . . . That’s how you build an audience,” Everist said.

History’s sister channel Lifetime — both are owned by A&E Television Networks — keeps adding formats to its repertoire, although it’s not always clear whether there is an overarching theme. The network runs dramas such as “Army Wives,” syndicated series such as “How I Met Your Mother” and reality shows such as “Project Runway.”

Rob Sharenow, Lifetime’s executive vice president of programming, describes the network’s holdings as “a balanced portfolio of investments.” He said the advantage of having a varied slate of genres is “in a down market for one genre, you have yourself covered with the other.”

Sharenow explained that Lifetime is also hedging its investments by diversifying its formats. Producing a reality show such as “Dance Moms” comes at a fraction of the cost to produce a scripted series such as “Army Wives.”

A scripted series can pencil in at $1 million per episode, whereas reality shows come at 10 to 20 percent of that cost, estimates Williamson, of Central Michigan. Cable networks are taking that expense into consideration as they wade into dramas and sitcoms.

Bravo, for its part, is starting out with two scripted shows due out next year. The network that built the “Housewives” franchise is sticking to its lifestyles-of-the-rich-and-naughty theme. One show, “22 Birthdays,” follows wealthy families as they throw lavish parties, while “Blowing Sunshine” looks at the interactions of staff members and patients at a private rehab center.

“The best brands have a great portfolio of different types of experiences,” said Jerry Leo, executive vice president of program strategy and production for Bravo. “We’re strong now with six nights of original programming and it just made sense to take it to the next level. We’re close to the top 10 and believe scripted [shows] will catapult us there.”

Leo said Bravo never aimed to be a reality network; it just wanted to garner a strong enough following to justify the cost of scripted programming. After six years of growth, he said the company has the financial wherewithal to endure the risk of bankrolling a fictional series.

“Scripted is a natural fit for Bravo because the brand lends itself to drama,” said Gordon of MagnaGlobal. “It’s a little bit harder to think of a scripted series that would fit the TLC brand.”

It’s not like TLC hasn’t dabbled in scripted programming in the past, but those attempts have mainly been reenactments in documentaries.

“We are always open to exploring different formats, as long as they fit our brand promise,” Winter said. “We just don’t have anything in the works at present.”

For now, TLC plans to build upon its successful franchises. Winters said the network is expanding its Friday night block of wedding shows to Thursday, with two hours of “Four Weddings,” a bride competition. The network is also rolling out three more wedding shows next year, including “Maids of Dishonor,” a show about — you guessed it — troublesome maids of honor.

Tried and true

While it has been years since TLC has cracked the top 10 cable network ranks, Nielsen routinely lists several of its shows, including “Long Island Medium” and “Say Yes to the Dress,” as top prime-time cable programs among women.

Those shows have helped boost ad revenue, which SNL Kagan pegs at about $323 million, up from $297.4 million at the end of 2011. The channel airs in 99 million homes in the United States and 227 million abroad.

“TLC is parked in an area that is pretty versatile, has lots of potential and possibility for a wide audience,” said Robert Thompson, director of the Bleier Center for Television and Popular Culture at Syracuse University. “Even though they are a specialized network, they are specializing in an area that’s viable.”

Whether that area remains viable for much longer is hard to tell as viewers are fickle. They may tune in for three wedding shows, but six? Titillating often turns into tawdry, and repetition gets . . . well, repetitive.

Everist of Campbell Mithun says specialization may soon lose its value to advertisers.

“Viewership is fragmenting, and as things get more fragmented you can have a proliferation of more niche properties. The question becomes can they make money?” he said. “At some point, you’re going to get so fragmented that the audience reach you have becomes less valuable to general market advertisers.”

If TLC were to hit a long, dry spell with its shows, Thompson imagines the network may feel compelled to vary its formats. Switching up its tried-and-true formula will also depend on whether viewers reach a saturation point for reality TV.