The purpose of this paper is to quantify (in monetary terms) effects of building renovation in Croatia by comparing pre- and post- renovation energy expenses. Ex-post, bottom-up financial analysis was done by applying panel-data methodology on an initial sample of 495 public buildings which contained 49, 744 observations – monthly bills, which add up to a total of 513.5 million HRK. The fixed-effects model exhibits average savings which amount to approx. 13, 000 HRK yearly, per building. The important contribution of this paper lies in collecting raw data, filtering it, and applying contemporary econometric methodology in order to estimate micro-effects of nation-wide energy-efficiency programs.