Plumbing electrical hvac gas certified  

Advise them that you need to evaluate the current market, as well as the condition of each unit, to determine fair rent prior to any offer.In the meantime, ask them (do not provide them the info to simply confirm, find out what they believe to see if it is different from what you already know) to tell you what they are currently paying for rent; what did they pay for Security Deposit; do they own any of the major appliances, or were they supplied by LL; do all appliances operate properly; who is paying for gas, electric, cable, any other; do they have any animals (pets or Assistance Animals); do they have vehicles, make, model, current tags and insurance; where do they park; how do they handle household rubbish; are there any previous maintenance requests that have not been addressed; do they have any maintenance requests at this time; do they have any items stored outside of their unit (additional storage closets or?)

Renovation RiskIs the scope cosmetic… or are there structural, foundation, electrical, or environmental unknowns?

So far I've had the roof, electrical, plumbing, and HVAC inspected.

Im happy to rough it and have a background in residential electrical. 

And if I house hack with a duplex or 4 unit property and wanted to borrow enough to fix or update the roof HVAC or electrical to get rid of problems that would be devastating down the road.

You could get deals by being the guy who can assess electrical systems in properties investors are considering.

Actually, at 43 years, you also need to closely look at all of the plumbing, waste and supply, in the unit and out to the street, as well as the electrical system.

I had cost segregation guys run an engineered study, and the catch-up depreciation they uncovered delivered roughly $9,000 in actual tax savings on a $4,000 investment, a return that funded a meaningful chunk of my next down payment. 

Use Engineer Fabric TX 160 or 180 for rock.