For the past few months, homeowners’ estimates of their home prices grew closer and closer to the appraised amount, and in November they nearly hit the mark. However, homeowners couldn’t predict December’s sudden decrease.

For the first time in six months, the gap between homeowner estimates and the appraised prices widened, according to Quicken Loans’ National Home Price Perception Index.

The average appraised value fell 1.33% below homeowners’ expectations in December, a greater gap than November’s 1%.

This sudden reversal could be due to home prices slipping in December by 1.19% monthly. Despite the decrease, however, prices were still up by 3.85% annually.

Click to Enlarge

(Source: Quicken Loans)

There are, of course, some regional differences such as Philadelphia, where homeowners estimated their home values at a full 2.94% higher than the appraised value. On the other end of the spectrum, homeowners in Denver actually undershot by 3.04%.

“It’s our hope that homeowners use the HPPI’s unique data as an insight into their local housing market,” said Quicken Loans Chief Economist Bob Walters. “When consumers have a better grasp of their local market conditions, it can help influence their expectations and ultimately lead to a smoother mortgage or home sales process.”