A sharp recovery in home prices over the past few years has given homeowners considerably more equity to tap, about $825 billion collectively, according to Black Knight Financial Services. This is nearly 2 1/2 times the home equity that existed just four years ago, but tapping that equity, in the form of a home equity line of credit (HELOC), is far more difficult than it was in the last decade, when a home was synonymous with an ATM.

"There is no question that HELOCs being originated today are of exceptional credit quality," said Ben Graboske, senior vice president at Black Knight Data & Analytics. "In fact, HELOC originations in Q1 2015 had the highest-weighted average credit score on record."