If you install something like below and A/C unit has a metal window sash holder, person on outside should not be able to pull unit out or push unit in since window sash can't be pushed up and is snugged into this metal sash mount..I actually use these below on my windows when the A/C unit is installed as it does double duty for security and preventing A/C unit from falling out of window due to tenant accidentally opening window.

@Jd Martin after reading what you said I understand how vague my question was, I apologize.I wanted to live in the first duplex until I get 10 units or enough to pay for my dream home which is modest because I was raised in such a ugly and poor place that just having groceries is a luxury to me.I don't plan to have kids so having a small house with a pool and low maintenance would be a hoot and a half.

It is nice to have a site, but having one that generates leads takes good planning, probably good SEO, marketing, and a good URL that will help you rank.

This duplex has two small units and a large spacious lot in the back along with a three car garage.

A Montrealer AND a BP member!!!

If its in a neighborhood thats medium income and a lot of rentals then its fine, if its in a nicer upper class neighborhood then convert it back to a garage. 

The adjacent property is in limbo right now, with the $14k still owed, and a value of about $27k Not sure there is much I can do about that one.

I live in Franklin and it is 10 minutes to Cool Springs (mall and commercial area with every store imaginable) and you are just 30 minutes from Downtown which is not so much shopping, but great restaurants and a lot of events.

There is generally a floor and a ceiling on price per square foot, in any given area, and $20-30k for a couple hundred more SF might absolutely be right depending on the local market.

I have bought occupied properties, and as long as you give enough notice, I haven't had a problem getting in.