Also I had a friend work on the HVAC system.

I have had one on rentals before as well and I renewed one for 3 years on one of my properties where the hvac system was old hoping they would replace it. 

If you are looking for a system approach for a single unit, I'd consider looking into TenantCloud. 

Of course, you can pay for the premium version, but I doubt you will need it.The system uses “cards” that you move linearly from one step to the next as the sale/project progresses.

It's helpful....One of the most important things to know is the age of the house and major systems (HVAC, Roof, plumbing, etc) and then the size of the property. 

The Housing Authority does not know who you are or that you are owner unless you go through their vetting process and get previous owner "out" of their system. 

Once the essence of a system or process has proven successful over and over again, it becomes a principle which we can apply to our own process.

Unless you’ve got some system’s problem like a water heater or furnace.

Definitely following and encouraged someone else is where I'm at (even though I've got 27 doors there is ZERO system so wholesale is where I'm starting to build processes, delegate and create some traction).

I got lucky on these two things with my first building but when I started doing my SFH I quickly realized I was going to have to upgrade systems and the heating bill was killing me and the more buildings I looked at the more I started noticing the discrepancies between the taxes and utilities between properties in the same town and in different towns.