Why did my assessed value go up when I did not renovate anything?

Assessed value in Georgia is calculated at 40 percent of fair market value, and that fair market value estimate gets reset periodically based on sales trends in your area, not only on renovations you personally made. A county assessor can raise the estimated fair market value simply because nearby homes sold for more, even if your own property is unchanged. Reviewing the comparable sales the county used, and comparing them to your home's actual condition, is the first step if the new number looks off.