Although homeowner estimates of their property's value were steadily approaching appraised values throughout the latter half of 2016, the year closed out with the gap widening significantly.

It the latest calculation of its National Home Price Perception Index, the retail mortgage lender Quicken Loans determined that the average appraised value was 1.33 percent lower than a homeowner's expectation. This was the first time the gap between expectations and appraisal has widened since June.

The result is a reversal from recent months, when homeowner estimates were steadily getting closer to the appraised value. The typical appraisal was 1.69 percent lower than expected in July, 1.56 percent lower in August, 1.26 percent lower in September, 1.15 percent lower in October, and 1 percent lower in November.

The average gap between what a homeowner thought their property was worth and what an appraiser set the value at was at its lowest point in late 2008, when the typical appraisal came in more than 8 percent below a homeowner's expectation. Homeowner perceptions and appraised values gradually came closer together starting in 2011, and the average appraisal was about 2 percent greater than expected for much of 2014.

Home value expectations also vary considerably based on geographic area. The typical appraisal came in 1.52 percent lower than a homeowner's expectation in the Midwest, 1.45 percent lower in the Northeast, 1.34 percent lower in the South, and 1.06 percent lower in the West.

In 15 of the 27 major metropolitan areas analyzed by Quicken Loans, the average appraisal was greater than expected. Homeowners were most likely to be pleasantly surprised in Denver, where home values were 3.04 percent greater than expected on average; Portland, Oregon, where the average appraisal was 2.14 percent higher than expected; and Dallas, where the typical appraisal was 2.09 percent more than anticipated.

The average appraised value was lower than a homeowner's expectations in the remaining 12 cities. The gap was largest in Philadelphia, where the typical appraised value was 2.94 percent less than expected; in Baltimore, where it was 2.62 percent lower; and in Cleveland, where it was 2.09 percent lower.

Home values continued to show year-over-year growth, but were down from the previous month. The Home Value Index stood at 99.62, a decrease of 1.19 percent from November but an increase of 3.85 percent from December 2015. An index of 100 indicates that home values are equal to those in January 2005.

The average home values were down 2.08 percent in the West, 1.9 percent in the Northeast, 1.42 percent in the Midwest, and 0.11 percent in the Northeast when compared with the previous month. However, there was year-over-year growth of 2.14 percent in the Midwest, 2.21 percent in the Northeast, 4.17 percent in the South, and 4.69 percent in the West. The Home Value Index stood at 81.92 in the Midwest, 95.68 in the Northeast, 101.19 in the South, and 119.08 in the West.

"Home value growth has been mostly driven by enthusiastic buyers vying for a smaller than usual inventory of properties," said Bob Walters, chief economist at Quicken Loans. "Appraised values have dipped along with the seasonal decline in sales around the winter months. It's yet to be seen if value growth will build as sales rise in the spring, or as construction increases."

Quicken Loans' Home Price Perception Index is based on estimates provided by homeowners on refinance mortgage applications and the values supplied by appraisers later in the process. The Home Value Index is based on appraisal data from home purchases and refinances.