Data
Methodology
How the Address District Older Home Index is built, what each figure means and how to read a small sample.
What the index measures
The Address District Older Home Index counts older homes, ZIP code by ZIP code. An older home is a home built in 1980 or earlier. Homes with an unknown build year are not counted as older homes.
We use it to show where older homes make up much of the market, and how they price against new construction nearby. It is one of the ways we decide where to buy.
The sample
The full sample covers 10,474 homes in 1,196 ZIP codes. Of those homes, 3,937 were built in 1980 or earlier, or 37.6 percent. The index lists the 1,192 ZIP codes with at least one older home, 8,028 homes in all, of which 3,937 are older homes, or 49.0 percent. Those ZIP codes are in 39 states.
The columns
- Rank orders ZIP codes by the number of older homes in the sample, then by the number of homes. ZIP codes level on both share a rank.
- Homes is the number of homes in the sample for the ZIP code.
- Older homes is the number of those homes built in 1980 or earlier.
- Share is older homes divided by homes.
- Older vs new is the average price of older homes as a share of the average price of new construction in the same ZIP code. Above 100 percent, older homes averaged more than new ones.
- Minimum lot is the minimum lot size recorded for the ZIP code in the source data.
- Neighborhood names come from the source data. Cities, counties and coordinates come from the U.S. ZIP code database in the open-source zipcodes package, and are used for place names and for finding nearby neighborhoods in the index.
How to read it
Counts favor ZIP codes with more homes in the sample, and shares favor ZIP codes with fewer. Of the 1,192 ZIP codes in the index, 310 have a single home in the sample, so their share is 100 percent by definition. Only 238 have 10 or more homes. Every neighborhood page shows its sample size, and the full index can be filtered by it. Read small samples as a snapshot of the homes sampled rather than a measure of a whole ZIP code.
The source data has no comparison with new-construction prices for ZIP codes in Texas.
Corrections
To report an error in a ZIP code’s figures, use our contact form and include the ZIP code.
Not an appraisal
The index describes a sample of homes. It does not say what any particular home is worth. Owners should get a current valuation, and compare any offer, including ours, with what a listing could bring.