Despite an acceleration in home price growth in April, the average homeowner continued to overestimate how much their property was worth. This marked the fourth consecutive month where typical home value perceptions fell behind appraisals.

In the latest measurement of its Home Price Perception Index, the retail mortgage lender Quicken Loans found that the average appraisal in the United States was 1.9 percent lower than expected. The gap between appraisals and expectations grew from 1.47 percent in January, 1.69 percent in February, and 1.77 percent in March.

"The appraisal is one of the most important data points in a mortgage transaction," said Bill Banfield, vice president of Quicken Loans Capital Markets. "This single number can impact how much money a buyer needs to bring to closing, or the equity that is available to the homeowner on a refinance. If homeowners have a grasp on home value differences throughout their local area, it can lead to a smoother mortgage process."

Homeowners have typically overestimated the value of their property, according to Quicken Loans data. The average appraisal came in more than 8 percent below expectations at the start of the Great Recession. However, the average appraisal was about 2 percent more than expected for much of 2014.

Perceptions varied by region in April, with homeowners in the Northeast having the greatest difference from appraised values. The average appraisal in this region was 2.17 percent lower than expected. The average appraisal was 2.02 percent lower than expected in the Midwest, 1.83 percent lower in the South, and 1.65 percent lower in the West.

Quicken Loans also measures perceptions in 27 major metropolitan areas. The average appraisal was higher than expected in 15 cities, led by Denver (2.72 percent higher), Dallas (2.55 percent higher), and Portland, Ore. (1.44 percent higher).

Homeowners were most likely to overestimate the value of their property in Philadelphia, where the typical appraisal was 3.37 percent lower than a homeowner thought it was worth. The average appraisal was 3.01 percent lower than expected in Baltimore and 2.37 percent lower in Chicago.

The National Home Value Index for April stood at 101.52, up 1.06 percent from March and 5.08 percent from April 2016. An index of 100 indicates values equal to those of January 2005.

Price growth was strongest in the West, with the region's Home Value Index rising 1.03 percent from the previous month and 6.52 percent from the previous year to 122.04. In the South, the index of 103.79 was up 0.67 percent from March and 5.02 percent from April 2016.

The Northeast's Home Value Index of 97.27 marked a 1.96 percent increase from the previous month and 3.54 percent from the previous year. In the Midwest, the index rose 0.8 percent from March and 4.08 percent from April 2016 to 84.1.

Quicken Loans' monthly reports on home values and value perceptions are based on appraisal data from home purchases and refinances. Perceptions are determined by comparing the property value estimate a homeowner gives on a refinance mortgage application and the appraised value determined later in the process.