Have you investigated utilities?

I feel utilizing friends and family is a great way to start.

If you have a credit score that qualifies, I do utilize one DSCR loan program that can lend up to 80% LTC to a foreign national.

Utilizing their favorable financing relationships to then secure a ~$1M loan from a local credit union.

At houses we even have tenants pay those utilities. 

This could become the basis for taxation.There are multiple methodologies that are utilized by the tax assessor when determining a property's assessed value and which one is utilized is dependent on age, property type, region and other factors.

A low-cost way to do it would be to paint the walls, the garage door, and close off any access to utilities.

Include all utilities in the rent.

We would be only paying utilities in the unit above the garage and would have our own separate drive/yard.

In fact my former employer who owned and managed a portfolio that exceeded $1B utilized an asset protection system more simplified than what you propose.