Every appraisal leans on comparable sales: homes like yours that sold recently nearby. But "nearby" isn't defined. That choice can quietly move your value.
There's no fixed distance
Fannie Mae's guidelines ask appraisers to use the best available comparable sales, ideally recent and from the same market area. They don't set a fixed radius. Each appraiser decides how far to look, and explains the choice in the report.
What the federal data shows
The Uniform Appraisal Dataset reports the average distance from each home to its comparable sales. Across about 14 million purchase appraisals from 2019 to 2023:
In New Jersey, the gap is similar: 0.92 miles versus 0.54 miles. Cities are denser, so part of the gap is expected. But a tighter circle also means a home in a Black neighborhood is compared only with the blocks right around it. If those blocks were undervalued in the past, the low values keep repeating.
Our rule: the same radius for everyone
- Start at 1 mile for every home, in every neighborhood.
- Widen to 2 miles, then 5, only if there aren't at least 3 strong matches from the last 12 months.
- Ignore town lines. A great match across the border still counts.
Then every sale gets a match score from 0 to 100, so the closest, most similar homes count most. In our test on 9,326 New Jersey sales, this rule didn't discount homes in Newark, East Orange, Irvington, or Orange.