Hallway was sloped 2" from side to side so there was definitely structure or foundation issues, all the tenants smoked so saying there was a lingering smell of smoke is beyond an understatement, walls were literally orange and caked with cigarette smoke as was the soffit outside two windows, multiple broken windows, peeling paint, doors stuck shut from wear and tear, broken front doors, and the worst part was every tenant knew his name and addressed him as if they were old pals (big problem).

From running to crochet, cross stitching, biking, not drinking or smoking cigarettes (two and a half years just the other day) and I do all that I do to show them that anything is possible as long as you try and stick with it.My goals that I would like to achieve with real estate are that, I want to flip houses and have rentals.

From cigarette smoke that drifted inside to strong cologne to fragrant food smells, a couple hours and the place is ready again. 

They look like a cigarette; you rub one end of them against the paint and the chemical in them turns colors if there's lead.  

https://www.sciencealert.com/incense-could-be-more-harmful-than-cigarette-smoke-researchers-findYour lease should have clauses about health hazards, or open fire/burning.

Hotels use them to remove cigarette smell.

My fear: that someone smokes cigarettes in the house, that inspector might also smoke so cannot smell it, and my place is ruined.   

Example of yes: old kitchen, everything is obsolete, walls are yellow with stains from cigarette smoke.

Here's the quick overview of my numbers and projections with more detail in screenshots of my excel spreadsheets:Purchase Price:  $365,000Price Per Unit:  $60,833Two-Family:  $121,667Four-Family: $243,333Rehab Estimates:  $60,000 ($10K/unit) Estimated After Repair Value:  $575,000Loan:  90% LTV (of purchase price) @ 12% interest for 6 months with 2 points paid on exitProjected Cash-On-Cash Return:  29.35%Projected Internal Rate of Return:  51.02%Here's a picture of the current rent roll (two units were vacant) and my projection of the rent rollCurrent Rents:  (more details considering the numbers don't tell the whole story)Two-FamilyUnit 1 (2BR+):  VACANT - son-in-law lived here and moved out prior to closingUnit 2 (2BR):  VACANT - empty when I walked it... he was "finishing" itFour-FamilyUnit 1 (2BR):  $200/week H&HW included - one bedroom is painted entirely black, multiple windows are broken, and other weird things...Unit 2 (1BR):  $780/month H&HW included - only "normal" tenant in the buildingUnit 3 (Studio):  $150/week H&HW&E included - complete hoarder... floor to ceiling with junk except for a small path from his bed to the bathroom and the fridgeUnit 4 (Studio):  $155/week H&HW&E included - smokes in her apartment without a care in the world... had a lit cigarette while I was walking throughProjected Rents:Two-FamilyUnit 1 (2BR+):  $1,400/month (OWNER-OCCUPIED) nothing includedUnit 2 (2BR):  $1,200/month nothing includedFour-FamilyUnit 1 (2BR):  $1,200/month H&HW includedUnit 2 (1BR):  $1,100/month H&HW includedUnit 3 (Studio):  $1,000/mo H&HW&E includedUnit 4 (Studio):  $1,000/mo H&HW&E includedHere's how the numbers broke down for cash in and cash out:Actual and projected expenses for the properties (I was given a single sheet of paper with hand-written numbers). 

Also, I find that some people who smoke cigarettes inside also tend to make other poor decisions inside their homes.I allow 2 pets with breed and weight restrictions and require an extra $300 security deposit.