Sentence:  These towers are not only the product of advances in construction technology – and a global surfeit of super-rich buyers – but a <WSD>zoning</WSD> policy that allows a developer to acquire unused airspace nearby, add it to their own lot, and erect a vast structure without any kind of public review process taking place. 
Meaning of the word marked with <WSD> tags:  Legislative action for the purpose of regulating the use of property and the construction of buildings within the area under the jurisdiction of the legislative body concerned.