If we've all gotten so rich off skyrocketing home equity, how come we don't live like we're rich?

As a homeowner over the past several years, you've probably made a nice chunk of change in the form of equity in your home. In many markets, homes that sold for $100,000 a half-dozen years ago are now worth anywhere from $175,000 to $300,000. In some markets even more.

"If you have owned a home over the last five years, in some ways you've been a big winner," says Nicolas Retsinas, director of the Joint Center for Housing Studies at Harvard University. "Over the last several years it's like having a second job without ever having to work."

Last year, home values appreciated about 12 percent overall nationwide, according to statistics from Neala Richardson, the principal economist with Freddie Mac. On average, appreciation usually runs between 2 percent and 3 percent, according to the Office of Federal Housing Enterprise Oversight, or 5 percent to 6 percent, according to Freddie Mac.

The problem is, that money only exists on paper.

Traditionally, the only way to get your hands on it is to sell your home, refinance the mortgage or borrow against it. Or you could just enjoy knowing that you made a wise purchase.

It's also a double-edged sword. The value of the house you bought might have skyrocketed. But so has the price you'd pay if you wanted to turn around and buy the same house again today. Net sum gain: nada.

Sneaky rich
"We call it 'stealth equity,' where you're living in a home for a while, the market's taken off and you've ridden the tide up," says real estate broker Sid Davis, author of "A Survival Guide for Selling a Home."

"It kind of sneaks up on you," Davis says, "It's phantom wealth. It's on paper."

But having $250,000 in equity isn't like having $250,000 in the bank.

The value is real enough, but you also have to be really careful with it, says Eric Tyson, author of "Mind Over Money: Your Path to Wealth and Happiness."

"You don't want to go overboard spending money because you have wealth on paper. That's where people get in trouble."

All the same, "it's part of your net worth," he says. "If you don't tap it or use it during your lifetime it will go to your heirs."

And if property values decline?

"It might not be worth as much as it is today," he says. "But real estate values are pretty solid."

Just keep your new-found wealth in perspective, says William Poorvu, professor emeritus at Harvard Business School and co-author of "The Real Estate Game."

"Don't think that because your house price has gone up that you can change your lifestyle dramatically," says Poorvu. He likens it to those who got wealthy on paper during the tech boom.