Im local and can connect you with a few realtors, private lenders, and a construction lender that may be good fits for you.

Does anyone have any recommendations, or even better any spreadsheets, excel or web-based, they use to keep track of all construction expenses for Flip/BRRRR properties? 

Over a week is crazy for an outage unless we are talking hurricane, tornado or fire.I am betting it is internal to the site.

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.

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.

Your best bet is to find someone doing the work in your area and picking his/her brain. 

Hey @Donald Tsung - your best bet may be to chat with a couple of active brokers in the area that you're scoping out.