Optimizing NOI

[Kyle K.]

I've been trying to search for various ways to optimize the NOI of the various apartment buildings in my company's portfolio outside of the obvious, no-**** variety (i.e. increasing rents, curing vacancy). These solutions would have to pay off within 2-years (the typical holding period of the buildings in the portfolio) so something like installing solar panels wouldn't fit the bill. Any suggestions, links, or other references would be greatly appreciated.