Determining Depreciation Write Off

[Christopher J Lemmon]

I have 2 SFR that were purchased and placed into service this year. I have one more that was a personal residence that I placed into rental service at the beginning of this year. How do I determine what the depreciation basis for these properties is? Is it a 90/10 split? 85/15? Do I need to look it up on the county records? What are the rules? The first time I did this the tax advisor who was advising me simply said it's always a 90/10 split but I want to hear what other people think?