In the house price prediction example of Practical Statistics for Data Scientists (by Bruce, Bruce, and Gedeck; p. 168), the median residual for each zip code is taken and binned. The authors note that "using the residuals to help guide the regression fitting is a fundamental step in the modeling process".
Is it right that you can take the residuals from an initial model, and use them (or transform/combine them with other variables) to improve the model further? I was trying to look for further examples online and on this site but I can't seem to find the right search results for this.