Use a home equity loan (fixed debt) instead of a HELOC (variable equity) and build an additional unit you can rent out in your own backyard.

Coffered ceilings, low corner additions etc.Anyone can slap lipstick on a pig, looking for high value add in high demand markets is where the $ is.

In addition to taking 6-9 months to close, they are also subject to (i) annual audits, (ii) annual REAC property inspections, (iii) recurring annual MIP payments on top of your interest rate, (iv) large initial deposits to the replacement reserve, (v) commercial space limitations to 15-20% EGI / 25% NRA, and (vi) less forgiving underwriting with 7.00% minimum vacancy rates when determining our underwritten NOI.

You should always require them to add you to their policy as "additional insured" or "additional interest" and you will be notified if they cancel or change their policy.

To support my seller and seize a valuable opportunity, my business partner and I decided to purchase the property ourselves.

if there is appreciation, but you wouldn’t sell your current home tax free and buy a neighboring home to rent out, (There by raising your cost basis for additional depreciation and lower capital gains tax.) then it probably doesn’t make a good rental property. . 

Unless you suddenly become a stellar STR Host and property (requiring additional spending), why not sell and make some better financial decisions....

WIth the new FHA & Fannie Mae legislation, many lenders are forecasting the rental income from additional units, even if they're not a zoned duplex.

Your best option may be to increase the rent to cover the additional expense.

For short term rental booking that is cancelled early, the guest is to leave on the day of cancellation and the host will not get paid for any additional nights.