## 2 Researching Space Efficiency in High-Rise Timber Residential Towers  
Researching space efficiency in high-rise timber residential structures is crucial for following reasons, encompassing environmental sustainability, urban planning, resource management, and human well-being:  
1. Environmental sustainability [54; 55; 56]: Timber, as a renewable and carbon-sequestering material, offers significant potential for reducing the carbon footprint of buildings. High-rise timber residential buildings have a lower embodied carbon footprint compared to traditional structures. Space efficiency studies in such buildings enable the quantification of the environmental benefits achieved through the optimized use of timber resources, including reduced energy consumption, greenhouse gas emissions, and resource depletion. 2. Urban planning and density [57; 58; 59]: Urban areas face challenges related to population growth and limited land availability. High-rise timber buildings provide a sustainable solution by offering vertical density while minimizing land use. Space efficiency analyses help urban planners determine the optimal distribution of residential units within a building footprint, maximizing population density without compromising livability or architectural integrity. This approach considers factors such as building height, floor area ratio, and population density to inform urban development policies and strategies. 3. Resource management [60; 61; 62]: Timber is known for its lightweight nature and low energy requirements during manufacturing and construction. Space efficiency studies in high-rise timber residential buildings focus on optimizing material usage, minimizing waste, and maximizing resource utilization. Scientific methods, such as life cycle assessments and material flow analyses, quantify the environmental impacts associated with different space configurations, guiding decision-making processes towards more sustainable construction practices. 4. Human well-being and comfort [63; 64; 65]: Research in environmental psychology and building science emphasizes the importance of indoor environmental quality for occupants' health and well-being. Space-efficient designs in high-rise timber buildings aim to enhance natural lighting, ventilation, and thermal comfort while promoting access to outdoor spaces and views. Scientific measurements, such as daylighting analysis, indoor air quality monitoring, and occupant satisfaction surveys, provide empirical evidence of the positive effects of space efficiency on human health, productivity, and satisfaction. Structural integrity and safety [66; 67; 68]: High-rise timber buildings must meet stringent structural requirements to ensure occupant safety and building resilience. Space efficiency studies consider structural design parameters, such as load-bearing capacity, lateral stability, and fire resistance, in conjunction with spatial layouts. Advanced computational modeling and simulation techniques, including finite element analysis and performance-based design, assess the structural performance of different space configurations under various loading and environmental conditions, informing design decisions and regulatory compliance. 6. Economic viability [69; 70; 71]: Space efficiency directly impacts the economic feasibility and profitability of high-rise timber residential projects. Scientific cost-benefit analyses evaluate the financial implications of different space configurations, taking into account construction costs, operational expenses, rental income, and market demand. Optimization algorithms and decision support tools help developers and investors identify the most economically viable design solutions that maximize returns on investment while meeting sustainability objectives. The authors underscore the significance of space efficiency in boosting financial returns, occupant well-being, and environmental sustainability within vertical urban settings, albeit without delving into sustainable planning aspects due to data constraints.