双重结构指城市既有局部单元结构，其源于从所有空间到其他空间的米制距离，也有不同尺度下联系各个局部单元的网络，超越局部性，体现了城市的整体特征。
双重结构
Sources
Hillier, B. (2001), A Theory of the City as Object: Or, how spatial laws mediate the social construction of urban space. In: Proceedings of 3rd International Space Syntax Symposium Atlanta 2001, 02.1-02.28. pp. 02.21;
Hillier, B. (2009),Spatial sustainability in cities: organic patterns and sustainable forms. In: Koch, D. and Marcus, L. and Steen, J., (eds.) Proceedings of the 7th International Space Syntax Symposium. (pp. p. 1). Royal Institute of Technology (KTH): Stockholm, Sweden.pp. k01.4-5.
Hillier, B., Turner, A., Yang, T., Park, H-T. (2007, 2010) Metric and topo-geometric properties of urban street networks: some convergencies, divergencies and new results. The Journal of Space Syntax, V(1) 2, 258-279. pp.259