Aim/purpose – Energy is traditionally produced using fossil fuels as raw materials, which impacts the environment negatively. Due to the scarcity of fossil fuel supplies, rising prices of energy carriers, and global trends, consumers are turning to renewable energy sources (RES) for home heating. The aim of this study was to determine whether the choice of house heating system using different sources than fossil fuels is driven by any additional components of single-family house users’ purchasing decisions besides cost. Based on research results, the prospects for further transformation of thermal ener- gy in single-family housing in Poland towards RES were determined. Design/methodology/approach – The research on the inhabitants of single-family houses was conducted in December 2022 in Poland. The research method used was a survey using the CATI and CAWI techniques. 600 respondents filled out the question- naire. The results were statistically analyzed. A non-parametric Kruskal-Wallis test (non- -parametric ANOVA) and a post-hoc test were used. The distributions’ normality and the variances’ homogeneity were measured using Kolmogorov–Smirnov and Brownian– –Forsythe tests. Calculations were performed using Statistica software. Findings – The choice of heating energy source in single-family houses, taking CO2 emis- sions into account, is not dictated by income level. Instead, it is determined by the number of people in the household. More numerous households opt for a zero-emission heat source. Households using emission-based heating energy sources are significantly more driven by the cost of using heating appliances; their purchase price, reliability, and product quality are more important than those using zero-emission methods. The partial use of renewable energy source solutions promotes further investment in emission-free heat sources. Research implications/limitations – The analysis illustrates the state of thermal trans- formation in single-family houses during the energy transition process at the national level. A limitation of the research is that it samples only one EU country struggling with too high CO2 emissions compared to other countries. Originality/value/contribution – A unique approach used in this study is to address the variation in incentives for renewable energy purchasing decisions, considering CO2 emissions. This aspect, although noticeable to some extent, is not directly taken into account by users who do not have the tools to assess their CO2 emissions. However, the proposed research approach showed that the CO2 emission level of a heating system is a factor differentiating some aspects of the decision-making process of system users. In particular, it showed what elements of the decision are essential in households that have not yet taken any action towards energy transformation. Keywords: energy, decision-making process, heat source, hybrid heat sources, emis- sion-free heat sources, consumers’ characteristics. JEL Classification: Q56, G51, O13.
