What does it mean to develop a comprehensive property project on the superstructure?

On the existing infrastructure, the use of air or underground space to build or rebuild comprehensive property projects. Refers to the use of air or underground space, in the existing urban infrastructure (such as subway, highway, railway, airport, etc.) on the new or rebuilt comprehensive property projects. These projects generally include commercial, residential, office, hotel, cultural and entertainment functions. Through the diversified use of space on limited land, the land use benefit can be maximized and the urban space utilization rate can be improved. This development model can reduce the occupation of the original land and improve the comprehensive economic and social benefits of the city.