By far the most common question is "What zip code should I invest in?"

The highest yield possible, bar none of any strategy, is to buy a note at a discount and refinance it days latter receiving the UPB or close to it, they yield skyrockets!

I understand the second part, just not the reason why it is advisable to take the depreciation in that case.Because the way the IRS code is worded it's required and you're taxed on the amount that SHOULD have been taken whether you take it or not. 

 - If you live someplace with stringent energy codes, consider insulation costs when framing (i.e., don't use 2x4 framing in places where you need R-20 insulation) -- this reduces your need for expensive insulation solutions.Also as Karen and others have said, buy materials that are decent but can be had inexpensively -- ceramic tile, carpet, less desirable granite slabs, etc.

I'm not even sure how they ever passed the low bar of occupancy inspection they were that bad.  

-building codes everywhere are becoming more and more stringent in regards to energy use.  

If you're legally allowed to own the property I imagine you're allowed to do anything you want with it so long as it conforms to local laws and code. 

Another perk, is you can get codes to go look at properties whenever you want.

Both properties happen to vacant lots that used to have single family homes on them and have since been demolished (one for being burnt down and the other for code violations).The thing is, I'm not really sure what to do with the lots.  

You need to call the assessors office and building and permits to dig for info.If the 3 plex is grandfathered in or was never allowed to begin with then you can't buy based on the seller shown cash flow model because if you will not be allowed to do that you will not make that gross income for rents.You need to see if it is even allowed and then if it was remodeled is it up to code and permitted??