This study evaluates the productivity of energy efficiency (EE) measures taken at the regional level employing a set of non-parametric statistical methods. The first aspect is investigating the impact of various energy efficiency measures. A high proportion of the population lives in apartment buildings, with limited opportunities to manage their own energy efficiency. The second research aspect of this paper is the study of the effectiveness of various energy efficiency measures in the context of low energy prices. Our analysis indicates that only two tools exert a long-term positive effect on reducing the economy’s energy intensity for all regions. This is the use of combined heat sources in large cities and implementing ISO 50001 in large companies. These two energy efficiency measures work even under low energy prices, which do not sufficiently stimulate the introduction of innovative energy-saving technologies.