Sustainable three-dimensional (3D) space optimization in high-density urban areas: Drivers, synergies, and multi-method insights
Received date: 2025-06-19
Revised date: 2025-11-17
Accepted date: 2026-04-29
Online published: 2026-05-22
Spatial conflicts in high-density urban areas impede sustainable development, therefore, such cities urgently require sustainable three-dimensional (3D) space optimization. However, existing studies lack a systematic understanding of driving factors and stakeholder differences. This study established an integrated framework using grounded theory analysis of stakeholder interviews, a bibliometric review of academic literature, and system dynamic model and identified five core drivers (regional suitability, human-centred philosophy, innovative design, management capacity, and transformative technology) for sustainable 3D space optimization in high-density urban areas of Zhejiang Province, China. We compared word frequency counts from interviews using co-occurrence analysis in the literature to highlight divergent stakeholder priorities. Word frequency analysis revealed that residents mentioned keywords about human-centred philosophy approximately three times more frequently than experts, highlighting notable divergences in priorities among the stakeholders. Moreover, while co-occurrence analysis identified management capacity as a central theme in scholarly discourse, word frequency analysis ranked it the last among practitioners, underscoring a notable academic-practical difference. Ultimately, based on grounded theory and co-occurrence analyses, we developed a conceptual framework reflecting the relationships between the five core factors and their internal functions. This framework integrates urban research methodologies, providing planners with flexible tools and suggesting the formulation of policies based on actual circumstances, to achieve sustainable development in high-density urban areas.
KONG Bowen , LIU Haoxuan , ZHANG Luyao , TANG Chun’an , ZOU Baoping . Sustainable three-dimensional (3D) space optimization in high-density urban areas: Drivers, synergies, and multi-method insights[J]. Regional Sustainability, 2026 , 7(3) : 100348 . DOI: 10.1016/j.regsus.2026.100348
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