The building sector plays a key role in meeting the Green Deal's goal of net-zero emissions by 2050, as residential heating and cooling account for a significant portion of the EU's energy consumption, with much of it still reliant on fossil fuels. The 'Fit for 55' legislative package aims to reduce emissions by 55% by 2030, but its fragmented structure presents challenges, and gaps remain for full decarbonisation. The study focuses on whether the EU is on track for decarbonisation, aligning with 2050 goals, and addressing gaps in the 2040 framework.