Un-planned obsolescence

What happens when large tracts of homes or apartments become dated or decrepit, en masse? Large projects - that is, those that cover large horizontal areas of land with private streets - may be tolerable or even pleasant when first constructed, but too often they are arranged in a fashion that will insure that they are the slums of tomorrow. 

Consider a large complex of apartments, with a single entrance, and a meandering network of private streets.  As the cheaply built buildings age, the apartments furthest from the entry have the double curse of being run-down, and deep within the slum.  On a conventional street grid, this unit could easily be sold off or demolished.  As is, it will likely continue to decay and become more dangerous until the entire complex is razed.

Urbanists argure for a more traditional block and alley street grid because it creates "good bones."  Infrastructure needs to be planned for the long term.  Then, it is financially and logistically easier to renovate or replace individual buildings within a development.

(Case study photos forthcoming...Pickwick Farms, Mollenkopf)