I plan to cash out and refinance after completing the unit, and using the remaining funds to construct additional units.

For newly constructed, purchased or renovated properties and also retroactive generally over the last 10 years, building components are properly classified into individual units of property and accurate recovery periods for computing depreciation deductions.

My wife is a licensed Realtor, and runs my office for our construction company.

You may want to look at buying a new construction home and doing a self-manage for the first tenant. 

@Yannick VezPre-construction properties are sold everywhere, including in the US.

I have some experience in multi-family fix and hold but am new to new construction (ground up). 

. - Look for properties with a large backyard and/or detached garage that would work well with an ADU and learn the ins and outs of the new CO laws that essentially have rezone most of the state to require approval for new ADU construction.- Underwrite the property to breakeven or small positive cash flow as a standalone long-term rental to a single tenant.

Perhaps do a new construction single or multiPerhaps!

A new construction loan Might be more difficult to qualify for than an existing structure loan.

For example, in Indianapolis, there are new construction duplexes priced at around $400-450k with strong rental returns.