The paper investigates the evolution of electricity-driven and gas-driven heat pumps technologies used for heating in the residential building stock in Belgium in the market. A base and predictive scenarios are considered. The base scenario includes the current share of the existing heat pumps in the Belgian market while the predictive scenario considers the increased share of the studied heating systems based on the evolution of the buildings envelope over the period 2020-2050. Two different types of heat pumps are considered, one driven by electricity which performance indicators are based on the literature, while experimental data is used for natural gas-driven heat pumps. The latter is modeled in an empirical way based on the system operating conditions and weather data. This paper presents the entire housing stock in Belgium which is divided in 752 cases. A tree structure model defining Belgian housing typology was created, characterizing Belgian residential building stock in terms of various parameters ... : CLIMA 2022 conference, 2022: CLIMA 2022 The 14th REHVA HVAC World Congress ...