I recently installed the Less Abandonment modd which raises the higher wealth development requirements so that they are not at the same level as what causes sims to abandon them. So far I it seems to work, but it still does not solve the problem of redevelopment.
In the game sometimes a medium or high wealth building will depreciate and become occupied by lower wealth level jobs or sims. Also sometimes you have abandonment issues due to transport or water issues, and if you don't realize it and save the game, then you have to hopefully find those buildings yourself and demolish them. I believe both of these ideas brings some realism to the game. What is unrealistic is that the game does not ever redevelop the depreciated buildings to a lower wealth building type, or reoccupy or redevelop the abandoned buildings for transport or water issues if the issues have been resolved and there is a demand for that building type.
Does anyone know of a modd that provides a mechanism for the game to redevelop to lower wealth buildings, or reoccupy or redevelop abandoned buildings? If such a modd does not exist, then would it be possible for someone to write a modd that would give a reoccupied at a lower wealth level or abandoned building a 5% chance each month to redevelop to a lower wealth occupancy or for abandoned buildings to reoccupy provided desirability requirements are met and there is a demand for that building type? I believe such a modd would bring greater realism to the game.
Maybe that will partially answer your question:
the only way I know to re-develop abandoned buildings or get higher wealth buildings is to make a click-and-drag with the Maxis forest planter on the area. This also makes it possible to new lot to grow on zoned spaces that have remained empty yet. Generally it will take a few months in the game clock before seeing the effect.