Jennifer Gilmer owns Jennifer Gilmer Kitchen & Bath in Bethesda, Md. She says that STEM skills are vital for designing. “You don’t survive unless you have these kinds of technical skills.” (Michael S. Williamson/The Washington Post)

When I think of STEM, I think of those brainiacs gifted in science, technology, engineering and mathematics who go on to lucrative careers in things like Big Pharma, architecture, high tech and Wall Street finance.

What I don’t think of when it comes to STEM is a career designing kitchens and baths.

But I should, because you need to be a bit of a geek to go with your artistic side.

“It’s a very specialized field,” said Jennifer Gilmer, owner of an eponymous kitchen design firm along Wisconsin Avenue in Bethesda.

Jennifer Gilmer Kitchen and Bath is on a strip known as the Rodeo Drive of Kitchens. Also there are Kitchen and Bath Studios, AAI Poggenpohl, and KBR Kitchen and Bath. Farther up Wisconsin are Reico Kitchen and Bath, and Stuart Kitchens.

There must be money in this business. Gilmer’s company grosses between $4.5 million and $5.5 million a year on the 40 to 60 jobs it performs annually. The average kitchen, including installation, runs about $100,000, although jobs start at $50,000 and reach $450,000.

The entire business and its 12 employees are contained in a colorful, window-filled 5,500-square-foot showroom for which Gilmer pays $10,000 a month.

I like talking to Gilmer. She speaks in clipped, no-nonsense sentences, like many small-business owners I have met who have no time to waste (although she loves her golf game).

Gilmer swears by premium appliances made by brands such as Miele and Sub-Zero, with their $10,000 refrigerators and $3,500 steam ovens. She didn’t take kindly to my description of her business as a “high-end kitchen designer.” Her clients are centered in Potomac, Chevy Chase, Bethesda, Northwest Washington and the leafy parts of Northern Virginia.

“We can be high end, but we also have competitive cabinet lines,” she said, adding that a Sub-Zero refrigerator lasts decades. “Our design work is high end, but the prices can vary depending on the products customers pick.”

Details are everything in designing kitchens, which is why engineering, math and drafting are useful skills. Designers must know when a cabinet door is too heavy for a hinge. Or whether a “slider system” under kitchen doors makes for a smooth glide. It’s making sure that the granite counter you like — and which means your kid will go to public school instead of private school — is perfectly cut and measured.

“You have to be great technically,” said Gilmer, 52. “You have to be able to draft, be good at math. But you also have to engineer, understand how things go together. You don’t survive unless you have these kinds of technical skills.”

And I thought kitchens were all about picking out refrigerators, stoves and the right faucet. That’s the fun stuff, it turns out.

Kitchen designers can earn from $80,000 to $200,000 a year, depending on how hard they work. They generally receive about 8 to 11 percent of the total cost of the kitchen, while Gilmer receives about 5 percent of the total cost for the job.

Then there are the bonuses. Experienced designers with strong client lists are expected to sell more than $1 million a year in kitchens and baths. If they make their goals, they can receive a 1 percent bonus.

Gilmer does fine. She earns a six-figure income plus a share of the profits — when there are profits. She said most years she is profitable.

Gilmer, who grew up about a mile down Wisconsin Avenue from her store, confirmed what little I know about the kitchen business: It’s all about the cabinets.

The most lucrative cabinet margins can run 100 percent or more, by far the most profitable item in a renovation project. Because each kitchen is different, cabinets are often custom-ordered and built by manufacturers.

Gilmer charges an average upfront retainer of $1,500 to $5,000 to design kitchens and baths. If the client does not go forward, Gilmer keeps the retainer. If they do proceed, half goes back to the client.

Gilmer has relationships with several contracting firms, which she recommends to her clients to handle the installation. Outsourcing the installation keeps Gilmer’s head count low.

Like any smart boss. Gilmer spends a lot of time on hiring because her personnel are everything. “It takes a long time to find the right people,” she said. “I weed them out.”

Gilmer has kitchens and design in her blood. Her godfather was the late Lawrence O’Brien, who was Democratic National Committee chairman and commissioner of the National Basketball Association. He grandfather was a civil engineer and owned a Maytag appliance store in Latrobe, Pa. Her mother drafted plans for Navy aircraft during World War II at a Glenn L. Martin aircraft plant in Baltimore.

Gilmer, whose father was an attorney who prosecuted Japanese war criminals, was the youngest of eight children and the only one without a college degree.

“I make the most money of any of them,” she said.

A natural at mathematics, she took drafting classes during and after high school.

One of the exercises in drafting school was kitchen drawings.

“I can’t explain why I love it,” said Gilmer, who co-authored a book called “The Kitchen Bible.” “It just resonates. I love math and I love art.”

She has been at it for more than three decades, starting at a small, family-owned shop in McLean, Va., called Kitchen Galleries in 1983. That was followed by a stint at Tunis Kitchens in Bethesda, where she earned more than $80,000 a year as one of the top producers.

She and another Tunis employee eventually partnered to open their own shop. Gilmer funded her half of the business with $60,000 she borrowed from her father — $50,000 went into the enterprise while she lived on the other $10,000

Gilmer split off four years later, in 1997, to go out on her own. Her former partner bought her out for $250,000, which she rolled into her own firm. Gilmer sent a mailing to 300 or so clients she had built up over her career, and then it was just word of mouth. She has been around long enough to get repeat business. One client has moved so frequently that Gilmer has designed six kitchens for the client.

I got a fairly good vibe when I visited her showroom last week. There’s something cheerful about being surrounded by all that sophisticated lighting, state-of-the art counters, glossy appliances and faucets that look like something out of “Star Trek.”

Gilmer said one of the things she learned in 30 years is that a smoothly run workplace gives off a positive vibe that customers pick up on. “Being at work should feel as good as it feels to be at home,” she said. Translation: “My employees would be so happy that they would look forward to coming in to work.”

If I were making $200,000 designing kitchens, I would be happy, too.