Other thoughts to consider -  it might be good to add a dedicated water heater and heating/cooling system to the ADU - so you aren't fighting with the tenant over the temperature or who is using too much hot water.   

The kits include compact fluorescent light bulbs of various wattages, LED night lights, smart power strip, whistle that attaches to your HVAC air filter and alerts you when it's time to change the filter, low flow shower heads, dryer vent cleaning brush, water temperature thermometer, refrigerator thermometer, weatherstripping, caulking, foam pipe insulators, window film, rain gauges, etc.

This is the hottest area of my city, new residential buildings are going up, renovating old warehouses and industrial parks with urban apartments.

I am partnering with a Commercial Mortgage Broker and  Environmental Attorney on a big real estate deal (a warehouse conversion).

@rickferguson I have a 9750 SqFt commercial office/warehouse building in Snellville that I own currently and rent to a Plumbing and A/C company.

Regular office they can pull up a truck late at night and be gone the next morning.Additionally if economy gets tough regular office tends to move to warehouse space for cheaper rent or keep office fully in their house etc.With medical tenant and also many retail type businesses their model requires a storefront and visibility.

The system consists of an outdoor compressor unit which is connected with copper pipes to an indoor unit that distributes the heated or cooled air into the home or building.Search Mini Split Warehouse on the web, they sell you any unit and they send it to your house, they can also take care of getting you an installer.

In my area we have a lot of warehouses serving online businesses like Amazon and Chewy.

You have to walk the scary basements, figure out the confusing locks in the freezing temperature, talk to neighbors, make quick evaluations of roofs, electric, flooring, plumbing . . .

If you are in a lower rent area, I'd go with laminate (or refinish hardwoods), go with pre-made cabinets from Lowes or Surplus Warehouse, you can do a formica or butcher block countertop and builder grade appliances.