Homeowners were less likely to make an accurate estimate of their property's appraised value at the start of 2019, according to the retail mortgage lender Quicken Loans. While the average appraisal remained within half a percentage point of a homeowner's perception, slowing home price appreciation was likely contributing to more inaccurate expectations.

The latest Home Price Perception Index from Quicken Loans found that the average appraisal was 0.47 percent lower than expected in January. While this marked the 11th consecutive month where the average appraisal has been within 0.5 percent of the homeowner's estimate, it was also the third month where the gap between the values widened.

Appraised values were 0.45 percent lower than expected in December. January's data still showed some year-over-year improvement, as the average appraisal in January 2018 was 0.6 percent lower than anticipated.

"It looks like the HPPI is seeing the start of a downward trend, in lock-step with pockets of moderating home values," said Bill Banfield, executive vice president of capital markets at Quicken Loans. "However, with the national measure still reporting appraisals less than half a percent lower than expected and with home values in the lowest performing metro area less than 2 percent lower than what homeowners estimated, the housing market is still in a healthy place."

The typical appraisal was 0.47 percent lower than expected in the Northeast region. Appraisals came in 0.62 percent lower than expected in the Midwest, 0.46 percent lower in the South, and 0.37 percent lower in the West.

In the 27 major metropolitan areas included in the report, appraisals were greater than expected in 18 cities. Boston homeowners were most likely to see values higher than they expected, with the average appraisal coming in 2.76 percent above the homeowner's estimate.

Appraisals were 2.24 percent greater than expected in Charlotte, N.C., 2.17 percent higher in Denver, and 1.91 percent higher in San Jose, Calif. On the other end of the spectrum, the average appraisal was 1.87 percent less than expected in Chicago, 1.64 percent lower in Cleveland, and 1.3 percent lower in Philadelphia.

Quicken Loans also looks at changes in home values with monthly updates to its Home Value Index. This figure compares home values to January 2005, with a value of 100 indicating values equal to those in January 2005.

The national index stood at 111.94 in January, up 0.65 percent from December and a year-over-year gain of 5.35 percent. The report found the most notable regional changes to be in the West and Midwest. In the former region, the Home Value Index of 135.57 was a drop of 0.38 percent from December and had an annual gain of 3.27 percent, the slowest of all regions. The Midwest had a modest 0.08 percent decline in values from the previous month and a 4.42 percent year-over-year increase, with its index standing at 91.47.

"While there have been some recent movements in the pace of home appreciation, the housing market is still very strong and is making positive movements across the country," said Banfield. "As homes in each market adjust for the rate of price appreciation, buyers and sellers may find that there is more to negotiate—and some potential complications—if the purchase price isn't supported by the appraised value. The appraised value will be derived from recent, proximate sales, and are the leading indicator for the direction of the local market."

The Home Value Index in the Northeast was up 0.59 percent from the previous month and 4.74 percent from the previous year to 103.4. The index in the South stood at 112.87, up 1.34 percent from December and 6.84 percent from January 2018.

Quicken Loans' Home Price Perception Index is based on refinance mortgages, where the homeowner estimates the value of their property and an appraised value is determined later in the process. The Home Value Index is based on a database of both purchase and refinance mortgages.