Monday, December 12, 2016

Atlanta Parcel Data

Fulton County provides detailed property assessment data online, including property assessment, home age, and the property shapefile. The map below uses this data to show the construction date of each building in Inman Park:

Inman Park has several homes built before 1900, but the two most common decades are the 1920's and the 2000's. Scroll down for an interactive version with hover-over (best on a computer).

The next visual shows median home age by neighborhood. The oldest Atlanta neighborhoods are near downtown. These neighborhoods include Inman Park, Midtown, Adair Park, and Grant Park, all of which have a median home age of 1920. The visual also allows the user to add condos and town-homes to the median age, which changes the age significantly for some neighborhoods.

Unfortunately, the ages of homes built in the 1960's or earlier are only approximate. The graph below shows that home ages in the county data tend to be rounded to the nearest five or ten years.

This graph also suggests that the listed age of many homes that are older than 1920 are rounded up to 1920. If you people would like to help me out, you could spend several days researching the age of your home and your neighbors' and contacting the Fulton assessment office to correct the age. I understand that this can be approximated by looking at historical plat records, but several minutes of googling didn't tell me how to find those. (Update: see links at bottom of post.)

To view a map of home ages for any Atlanta neighborhood in Fulton County, use the interactive below. Mouse over a parcel to see more details or use the zoom tools in the upper left.

Dekalb County does not have similar data files publicly available. City of Atlanta has a parcel shapefile that includes Dekalb county, but the data is a few years old and has limited fields. Both counties have very functional interactive GIS maps online (FultonDekalb), and property lookups (FultonDekalb).

The parcel data can also be used to map appraisal values. Here's Morningside/Lenox by appraisal value:

The modal appraisal value is $500-600K, but there are a few homes appraised at over $2 million. Cross-checking with Zillow shows that homes in Morningside/Lenox tend to be listed for about 20% more than their appraisal value. 

Morningside/Lenox is actually a little larger to the east than the above map portrays, but that portion is in Dekalb County.

Use the interactive tool below to view appraisal data for any Atlanta neighborhood in Fulton County. 

We can also view average appraisal value by neighborhood on the map below. I've made a similar map using Zillow data, but the map using appraisals covers more neighborhoods and includes values of all homes. On the other hand, appraisal values are often lower than actual sale prices.

The map above also allows the user to add condos and town-homes. This feature demonstrates the importance of density for affordability. When condos and town homes are excluded, Midtown contains 752 homes with a median value of $498K. When condos and town homes are included, Midtown contains 8,920 homes with a median value of $207K.

Let me know in the comments or on twitter if you have questions or find anything interesting in the data.

Update: a helpful commenter from reddit shared a few links to research home ages:

BTW, there's a great resource for researching your property's history hereYou aren't going to find historical plat records, the best you can do is the old Sanborn Fire Insurance mapsThose will at least show you the shape of the building. There are some other great historic city maps here.