Comparative studies in urban morphology based on systematic methods represent an underdeveloped branch of the field. The challenge is increased when comparisons are attempted not just across different areas within a country or region, but across cultural boundaries and across time. While the field is full of single-city case studies – and surely there remains a multitude of unstudied cities around the globe that deserve in-depth individual analysis – there is also a pressing need for comparative investigations to establish the broad patterns worldwide of similarity and difference, evolution and devolution, convergence and divergence in urban morphological dynamics and character. This paper does not claim to offer a comprehensive program for comparative studies in urban morphology, but it does attempt to demonstrate some systematic methods that can yield useful measures of similarity and difference across selected cultural divides. A possible framework for comparative urban morphology is presented, within which selected issues are explored with reference to personal work done in Italy, Brazil, China, Russian Alaska, and the continental United States.

It is a truism that centuries of historical development across a geographically spread-out world have created a rich variety of urban building traditions that invest cities with complex cultural meanings. This diversity seems at times overwhelming, given the almost endless variety of its specific details in particular places, and yet we must seek to understand all of them at some useful level of generality and, therefore, in some coherent way. The historically recent urbanization of much of the world's population has accelerated urban growth rates to unprecedented levels, which is producing new urban environments on a vast territorial scale that has never been seen before.

These new urban environments worldwide share many characteristics of design – for two compelling reasons. First, we live in an era of instant communications with strong pressures to create uniformly acceptable standards of living (and therefore of design) in the long march towards modernity. And, second, there is an age-old desire to be seen to reproduce what is currently fashionable, particularly in regions playing “catch-up” with more established ones. As a result, immense urban areas are being added to our existing cities that look staggeringly alike in all regions, no matter whether the locations are in New York City, Paris, Dubai, Beijing, or Putrajaya. Most dynamic cities in the world today contain central districts filled with modern highrise towers that, despite the architect-driven quirks of many of their individual buildings, exhibit skylines that are increasingly bland (and even boring) in their predictability and sameness. The resulting perception of geographical identity is often reduced to a handful of signature buildings that themselves could be found almost anywhere.