The average American homeowner owes $164,217 on his mortgage. That's a hefty sum, which explains why most of us chip away at paying it back over, oh, 30 years. And yet, certain homeowners pay off their mortgage at a much faster clip -- and it's not because they're millionaires, either.

Check out the stories of three homeowners who went to extreme lengths to pay off their mortgage in years rather than decades, and maybe you'll be inspired!

'I bought a home in the cheapest city in the U.S. and commuted'

Phil Lavoie, a 40-year-old software salesman, had always known he wanted to own a home. But homes in Chicago, where he lived, were so pricey that he was leery of saddling himself with a huge mortgage. Then five years ago, while catching up on the news, he had an idea.

"I read an article about how Indianapolis was the most affordable city in the nation," recalls Lavoie. At that time, he was working from home, taking business trips every week or two. "I just needed to live near an airport for my job," he says. "So I decided to pick up and move to Indianapolis."

Soon enough, he and his partner made good on that goal, buying a three-bedroom home for $145,000 -- a sum low enough, after they put 20% down, that they were able to pay it off in two years. While having a relatively small mortgage helped them whittle it down quickly, that doesn't mean they didn't feel the pinch.

"It involved a lot of delayed gratification," recalls Lavoie. The couple also didn't dine out for those two years and started a garden to save on the cost of fresh vegetables. Their home-cooked meals ended up having a side benefit: Lavoie lost 100 pounds.

Better still, he managed to pay off his mortgage at just 35 years old.

Lavoie has since moved to Key West, FL, and although he has a mortgage again, he says, "I would like to pay off this property, too." He's gotten hooked on living mortgage-free, especially come payday. In the world of addictions, this is not a bad one to have.

"That day when you get a paycheck and you're like, 'What are we going to do with this money?' is a weird and wonderful feeling," he says. "It makes you feel like you're winning a small lottery every week."

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'Job uncertainty convinced me I had to be mortgage-free'

Ever since buying her home in Portland, ME, Caroline Smith, 45, has felt it was imperative that she and her husband pay off the mortgage as early as possible.

"I didn't want to find myself aged out of my career and still paying a mortgage," says Smith, an economic developer for a regional planning agency.

Fortunately, she had the foresight more than a decade ago to embark on a well-orchestrated operation of buying real estate and investing the earnings.

"I flipped a bungalow for a less expensive home in the city," Smith explains. "Then I sank all the profits into the new house for 30% equity, which lowered the monthly payment enough that I could afford a 15-year mortgage." A 15-year mortgage typically has higher payments than the traditional 30-year mortgage.

At the same time, she was able to use the equity in her home to buy two properties that she rents out for income. This real estate juggling act eventually paid off: Smith is now thrilled to report that she's wiped out the mortgage on her residence.

"I paid off $150,000 in 11 years," she declares, "and not only did I pay off my mortgage early, but I am on track to retire at 48. Crazy, huh?"

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'I rented out my house and lived in the basement'

In the early 2000s, Sean Cooper's single mother was laid off -- and nearly lost their family home. Fear of going through the same experience haunted Cooper when he purchased his own house in Toronto in 2012 for $425,000 -- so erasing his mortgage debt ASAP was his top priority.

"Living on my own, I worried, 'If I lost my job, how would I pay my mortgage?'" says Cooper, 30, a pension analyst. "I didn't want to stress about it."

Cooper's plan was simple: Work like crazy and save every cent. He moonlighted with not one but two extra jobs: as a financial journalist and a grocery store meat department clerk (even though he's a vegetarian). He also decided to rent out his bungalow and live in the basement for added income. He didn't spend much money, either, forgoing outings with his friends.

It was a lot to sacrifice -- yet within a mere three years, Cooper had managed to pay off his entire mortgage. Since then, he has quit his grocery store gig and started socializing more. Yet certain frugal habits he picked up remain.

"I ride my bike to work, and I pack my lunch," he says. "And I'm still living in my basement." That's because he's now funneling money toward his retirement. The experience has also inspired him to write a book, due out next year: " Burn Your Mortgage: A Simple, Powerful Path to Financial Freedom."

"I knew that once I paid it off, I would have financial freedom," Cooper explains. "Just because the bank says it should take you 25 years to pay off your mortgage doesn't mean it has to be that way."

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