Abstract This paper seeks to analyse the adoption of Energy Efficiency Measures in non-residential buildings. Based on the concepts of agency theory and absorptive capacity, the propensity of Micro-, Small- and Medium-sized Enterprises in Portugal to adopt energy efficiency in lighting, insulation, and the replacement and operation of heating, was evaluated. To achieve this, an online survey was carried out, and the resultant data was treated using Probit models. The main findings suggest that absorptive capacity factors are a key reason for adopting more efficient and profitable technologies. Policymakers should provide assistance and information to the managers of these enterprises regarding the benefits of energy efficiency measures. Additionally, this paper shows that subsidiary enterprises are more likely to adopt energy efficiency measures. Although subsidiaries suffer pressures due to agency theory factors, they may also benefit from knowledge transfers from their parent enterprises. Most of the decisions and barriers considered by enterprises are not based on audits or the advice of energy management professionals, since more than 65% of the respondents have never performed an energy audit, and over 82% do not have an energy manager.