# Space Efficiency in European High-Rise Timber Buildings
## 4 Discussion
Similar variations were noted in residential and mixed-use towers. Additionally, research on over fifty Finnish mid-rise timber apartments showed space use ranging from 78% to 88%, with an average efficiency of 83% [38]. Moreover, studies on high-rise wooden residential [34] and office towers [37] showed space efficiencies ranging from 70% to 93% and 75% to 95%, with averages of 83% and 88%, respectively. In this paper, the average space utilization and core area-to-GFA percentage were 82% and 11%, respectively. The range displayed a broad spectrum, with the lowest space efficiency at 70% and the highest at 90%, whereas core area-to-GFA percentage varied from 4% to 21%. The marked disparity in space efficiency between timber and non-timber structural systems can be attributed to fundamental differences in their material characteristics and construction methodologies [79; 80; 81]. Timber structures capitalize on lightweight frames and panels that enable the use of slender structural elements, contrasting with the thicker components necessary in conventional concrete or steel buildings. This inherent advantage allows timber constructions to achieve reduced wall thicknesses and shallower floor depths, effectively maximizing the usable floor area. Moreover, timber's excellent strength-to-weight ratio facilitates longer spans and fewer internal supports, enhancing interior layout flexibility and spatial optimization. In contrast, non-timber systems such as concrete and steel require bulkier structural members to withstand comparable loads, resulting in thicker walls and deeper floor sections that inherently diminish overall usable space efficiency. To further improve space efficiency, this study suggests several strategies: optimizing core designs to minimize space consumption, employing advanced construction technologies to reduce material footprint, and exploring innovative architectural forms that enhance usable floor area without compromising structural integrity. Additionally, designers should integrate multifunctional spaces, implement flexible layouts that can adapt to changing needs, and utilize modular construction techniques to streamline the building process and enhance spatial utilization. By adopting these approaches, timber towers can achieve higher space efficiency, thereby contributing to their sustainability and economic viability while setting new benchmarks in urban design. The research presented valuable insights into the space efficiency of towering timber edifices in Europe, a rapidly expanding domain with significant environmental and economic advantages. However, several limitations need to be acknowledged. Firstly, the study primarily focused on European cases, potentially limiting the generalizability of its findings to other regions with distinct regulatory, cultural, and environmental con texts. Secondly, the analysis relied on a relatively modest sample size of 56 case studies, which might not fully capture the diversity and complexity of timber tower projects across Europe. Despite these limitations, the study provided crucial baseline data and findings that can inform architectural design practices, but further research with larger and more diverse datasets is warranted to comprehensively understand the factors influencing space efficiency in towering timber structures.