Kenny Cohn, owner of Kevco Building Services, supervises a crew at Reagan National Airport as they wash the interior and exterior windows, a twice-a-year project. (Dayna Smith/For The Washington Post)

Look up.

There’s a pretty fair chance those guys tracing figure-eights with their squeegees while hanging on the sides of buildings are with Kevco Building Services, of Montgomery County.

“The best part is when I hear people going by, look up and say, ‘I can’t believe people would do that. You can’t pay me enough to hang off a building,’ ” Kevco owner Kenny Cohn said. “My guys love the freedom of the outside. That’s what appealed to me. There is an immediate gratification of cleaning a window.”

You couldn’t get me up there. My idea of a safety net is my 401(k).

The Kevco army keeps windows clean for more than 500 buildings a year, many owned by Washington’s biggest real estate honchos: Brookfield Properties, Boston Properties, Vornado, JBG, Douglas Development. Twice a year, their squeegees sweep the glass at Reagan National and Washington Dulles International airports. They also clean at the University of Maryland and a big chunk of Crystal City.

Kenny Cohn, owner of KevCo Building Services. (Dayna Smith/For The Washington Post)

About half those jobs include washing windows. The rest involves cleaning parking garages and building facades.

(Nugget No. 1: The secret formula in the bucket is Dawn or Joy and cold water, with the occasional dash of ammonia.)

The company has never lost money in its 26 years.

Cohn, 55, grosses around $3 million a year and pays himself a six-figure salary. The profits are about 15 percent, which means the business clears $500,000 after everything.

About 70 percent of the revenue is from commercial clients, where the average job runs around $3,800. The rest is residential (the average home job is about $350), which includes cleaning gutters, siding and decks.

Kevco, based in the Montgomery County Airpark in Gaithersburg, has around 40 employees, including 34 window washers, divided into eight crews. The company has 16 vehicles and 24 pressure washers, which help sweep away stubborn sidewalk gum.

(Nugget No. 2: Hot water melts gum.)

But it’s washing thousands of windows every year that drives the business.

Cohn said his teams occasionally break a window, but fortunately no one has ever fallen. That helps keep his insurance bill at a manageable $150,000 or so a year. The major cost of the business is the payroll; employees make between $15 and $20 an hour. They also get health care, a 401(k) match and paid vacation up to three weeks a year.

Cohn, who lives in Gaithersburg with his wife, said the best part of the business is that it takes him places most people never see. He once trooped to the top of the Capitol dome (a former Kevco client), standing where the Statue of Freedom rests (which was down for restoration). He has even seen the offices of the justices of the Supreme Court of the United States, which is still a client.

Cohn grew up in Wheaton, Md., and has been washing windows since he was 14. He cleaned the laundry room in their apartment building for $2.25 an hour and started earning extra cash when residents asked him to clean their windows.

He studied business at the University of Maryland and kept cash in his pockets doing what he knew: cleaning windows. Kenny’s Window Cleaning started cleaning windows during summers and weekends in people’s houses, mostly in Silver Spring.

(Nugget No. 3: Kevco’s tallest job is the control tower at Dulles International Airport, which is 350 feet high.).

Cohn seems to always have had windows on his brain. After graduation, he worked for a company that sold and installed venetian blinds. He also knew intuitively that he needed to own a business to make money.

“I thought I was going to have the opportunity to buy into it. I didn’t get a piece of it, so I left,” he said.

This was 30 years ago when he had just gotten married. He was 26, and his new wife, Evalyn, told him: “Kenny, if you are going to start a business, do it now. Don’t look back in 20 years and wish you had done it.”

That was the catalyst. His family suggested he name it something that sounded more professional than Kenny’s Window Cleaning, so they had a contest and came up with Kevco (Kenny-EValyn-COhn). He sold his beloved Triumph TR6 car for $4,000 and bought a small pickup truck.

He started knocking on doors of businesses, and he bagged the Fitzgerald Auto Mall as one of his first clients. He still services Fitzgerald to this day.

Cohn himself doesn’t wash windows anymore. He works the local real-estate industry hard, attending association functions on the hunt for new clients.

“Like any other business, word of mouth is the lifeblood,” he said. “If a property manager likes you at one building, he will recommend you to his counterpart at another.”

April through June is the window­washing version of Christmas season. I asked him if he prays for rain, as the carwash industry does.

“It’s a mixed blessing, but typically we don’t like it. It plays havoc with our schedule, and there’s not that much dirty water from rain.”

He tries to keep his employees working even with poor weather, bringing them in the offices for training or reassigning them to garage cleaning. Most of the workers have gone through the industry’s certification program.

“We don’t hang a person from the building until they are fully trained. Our training process is very simple: We show you tools, the window cleaning squeegee. Right in our office, the supervisor teaches them the proper technique of how to remove soapy water from glass.”

And that is?

“We wet down the window totally. Then start at the top left-hand corner and come across to the right-hand corner to a 45-degree angle. Keep going back and forth with the figure 8 motion. It’s basically a squeegee removing water from glass and leaving it dry.”

On average, this takes about two minutes.

(Nugget No. 4: The window cleaner motto: “Never talk about what you see through the windows.”)

Cohn gets a kick out of cleaning the airports twice a year. He loves being around the jets, mostly because his first ambition was to become an airline pilot.

Of the two airports, Reagan is more complicated because of the shape of its windows and because the jets are so close to where Cohn’s people are working. They use 85-foot hydraulic lifts to get around the jets and service hard-to-reach windows. Dulles takes three weeks to clean, while Reagan National requires almost twice that time.

Like any other economic downturn, business slows down when companies cut back on their services. Still, his company has never lost money. And Cohn has never had a layoff.

“It’s not glamorous, but you have to have the work done. You have to keep the curb appeal of the buildings. The owners want to make sure their investment looks the best it can,” he said. “It’s one of the last, non-computerized industries out there.”