I ask because there is little difference in the mechanics of a real estate transaction inside of or outside of a retirement account. 

Unless you are a Slum Landlord with your own AC mechanic who you trust, you buy a new Unit.

New mechanicals (HVAC, electric, plumbing), kitchen, bathroom, adding a 1/2 bath in basement or 1st floor, new drywall, floors, paint, etc.

You want to make sure the mechanicals are all new and that the taxes have been reassessed and are valid.

i’ll buy & hold properties a mechanic shopkeep upgrading the businesses sit on reserves 

I updated the bathrooms, floors, kitchen, Mechanicals, sewer lateral, Paint, doors.

Not only will appliances and mechanicals need updating, but linens, furniture and decorations also need updates over time.

It is required to have a building permit/inspection and hire licensed professionals for Electrical, Mechanical, Plumbing, and structural engineering for load bearing, gas line work, and septic systems. 

New mechanicals.

You can focus on the mechanics of capital raising, the legal set up, good customer service, that's what I did when I got started nearly 22 years ago.