It was setup by my estate planning attorney and it provides rock solid protection of the assets while preserving ALL of the tax advantages.I know the gurus make LLCs look sexy and tout them as the must have accessory of all hip real estate investors, but they don't really provide the kind of protection the gurus claim.I urge you to seek competent counsel.

*******July 2021 Primary residence purchased in CA(The residence has 2 homes: a main home which we live in AND an ADU/ Accessory dwelling unit)*July- Oct 2021: we rent out the ADU for 90 days straight to one family (so it is not an STR and ADU is not eligible for bonus depreciation as I understand it)*Oct 2021: our family member moves into the ADU now that our renters have gone; and we continue to live in the main house.  

I live in Murray and they now allow legal ADU (Accessory Dwelling Unit) aka basement apartments.  

Ergo, Podio.Now here I am today, right now, finding ways to automate and outsource etc...and I stumble across the all too well known and coveted PODIO.

What you are wanting to build is an Accessory Dwelling Unit or Junior Dwelling Unit, which hopefully your zoning will allow.

As far as packing an accessory dwelling into your home and vacation renting. 

The other option is to build an addition with an ADU (accessory dwelling unit) finishing the house and adding another 650 sqft to the main house ( 3 bed 2 bath ) and a 550 sqft attached ADU (1 bed 1 bath). we could rent the ADU for appx $1000, to $1200 a month.

In the Utah market, the distinction lies in "owner occupied accessory apartment" vs "legal duplex."  

Put shelving in the showers to hold shampoos, soaps and razors(Command) makes great shelving for these accessories(Command Shower Water-Resistant, Clear Frosted, 1 Caddy, 4 Strips (BATH11-ES), 4.8 x 11.3 x 6", https://www.amazon.com/dp/B00H... ), makeup mirrors. supply in the kitchen anything that you would use in your own home. 

Hope this helps.Core and shell means not including any finishes, like cabinets, bathroom accessories, wood flooring, etc.