Plug it all into BNBCalc and share it so others can give you feedback- look at the tax savings via the "short-term loophole" at the bottom and learn how that functions as well as it can be a huge aspect of your investment.

Read the contract details, especially fees, eviction coverage, and maintenance info.

There are no penalty fees for paying off the loans early, FYI.Anything in this workflow that I'm missing? 

Also, keeping the ADU under 750sf means the city cannot charge you impact fees like parpk fees, sewer fees, school fees, etc.

Add up expenses from Day 1 of the build and see how long it would take to recoup that dollar amount with your projected NET profit - meaning after all expenses.... ie you charge $150 a night but after cleaning/supplies/ fees, you make a net $80.

Since you requested any book recommendations, I wanted to point you towards Tax Free Wealth by Tom Wheelwright. 

@Samuel Metcalf- sorry ...getting  heloc on the rental duplex  will be hard / impossible to obtain ....if you can  get one - it would be a great option to use for the  remodel / landscape ....if you have  50K equity in your primary -you likely dont have  ample equity position to get a HELOC  on it as the max  comboned loan to value for helc lenders is  85%  ( maybe  90% ) ...I would try getting helocs on both to see whats possible ...if no heloc is possible - use the cash on hand for the purchase down payment / closing costs / loan fee/ prepaids and then use future accumulated savings for landscaping 

Definitely discuss w your tax advisor too.  

., 17.5 years remaining for residential property).New Schedule: Simultaneously, start a new depreciation schedule for the additional cost basis attributed to the replacement property, following standard timeframes (27.5 years for residential, 39 years for commercial).Option 2: Treat as New AssetCombined Basis: Treat the entire cost basis of the replacement property (carried-over basis + additional funds invested) as if it were a newly acquired asset.Single Schedule: Depreciate the total cost basis over the standard timeframe for the replacement property type (27.5 years for residential or 39 years for commercial).If you choose option #2, you need to file an additional form (4652) with your tax return. 

I am currently using Zillow to screen tenants and had the application option turned on so I have candidates who paid $35.00 for the Zillow application fee.