In the summer of 2021, the European Commission presented a package of climate legislation (Fit for 55). It adjusts the European Union's (EU) policies on climate, energy, land use, transport, and taxation to reduce net greenhouse gas emissions by at least 55 % by 2030 compared to 1990 levels. 2030 has become a milestone and an intermediate target for carbon neutrality in 2050. What does this mean for different energy sectors? How will energy stakeholders act to achieve the ambitious goals of climate neutrality in the coming decades? Are the goals set achievable for Latvia and Baltics, and how can building sector energy consumers help with their behavior changing and recent technology introduction? To answer these questions different building stock energy modelling scenarios have been elaborated using the Baltic Backbone model to find the best cost-effective way to meet all requirements and needs. The main results of modelling are presented and analyzed in this paper.