On a permanent foundation? 

A dwelling structure is also generally defined as a enclosed structure with permanent walls and a roof.

the OP says the borrowers plans for this to be his permanent residence . 

But permanently moving the rent due date for one person would make my bookkeeping even more challenging. 

Quote from @William Thompson: •⁠ ⁠100% bonus depreciation is back—permanently•⁠ ⁠Estate exemption raised to $15M / $30M (huge for legacy planning)•⁠ ⁠SALT cap bumped to $40K (trust planning just got interesting)Big question: Are you doubling down on cost seg + bonus depreciation now, or reworking your structure to leverage trusts and deductions?

Me and my wife are looking at leaving the country for a year and then possibly moving out of the country permanently.

Because of that, I underwrite TICs outside SF as if they’ll remain TICs permanently, and I only get interested if the price per exclusive-use unit is compelling even without a conversion.

RV sites, at least here in AZ, is seasonal so converting RV sites to permanent monthly income is two fold.

I was curious about one of the things you said - "mortgage insurance (MI) on FHA loans is permanent unless you put down 10%+". 

This changes the game.Example: Studio Unit (fully furnished, permits, foundation included)1) Market Rate, No IncentiveBuild cost: $200–225K | Market rents today: $1,500–$2,000/mo | NOI: $12.6K–16.8K/yr | Yield: ~6–8% | Payback: 12–18 yrsSolid, but long payback and moderate yield.2) With Charlotte’s $80K Forgivable IncentiveEffective basis: $120–145K | Program rent cap (8 yrs): ~$1,100/mo → NOI ≈ $9.2K/yr | Yield during affordability: 6–8% | Forgiveness adds ~$10K/yr “earned income” | Payback to recover gross cost: ~11–13 yrsThe subsidy de-risks the deal—guaranteed inflows cover build cost faster.3) After 8 Years (rent cap lifts, market rents w/ 3% compounding)$1,500 today → $1,900 | $1,750 today → $2,217 | $2,000 today → $2,534Year-9 ROE after incentive: $200K build / $120K net basis → 13–18% | $225K build / $145K net basis → 11–15%You exit affordability with a permanently lower cost basis and market-rate income.