The rise of sustainable construction practices has led to increased use of timber structural systems across Spain. In Andalusia, the Life project “Wood for Future” developed a hybrid slab system combining timber joists and concrete slabs to merge sustainability with structural performance. This study analyzes both hybrid systems and all-timber slabs composed of joists spanning 3–6 m and 20–30 mm three-layer Solid Wood Panels. Acoustic performance tests were conducted to evaluate compliance with Spanish regulations. While all-timber systems demonstrated advantages in terms of reduced weight, fast assembly, and lower carbon footprint, acoustic tests revealed they fall short of minimum regulatory requirements. Conversely, hybrid systems offered better acoustic insulation but with increased environmental impact due to the use of concrete. To bridge the performance gap, the study proposes incorporating Structural Box systems—widely adopted in Northern Europe and some advanced Spanish regions—as an alternative. These offer enhanced acoustic and structural performance while maintaining sustainability benefits. The research also addresses technical, regulatory, socio-economic, and policy aspects to outline a roadmap for mid- and high-rise timber construction in Andalusia, aligned with sustainability and building quality goals.