They always lacked something and I will never have peace of mind. 

This policy will provide additional coverage above what your existing policy covers.

You also need a detailed explanation of each cost item to solidify a clear scope of work for that specific task.Experienced general contractors provide computerized plans to show the current existing conditions and the proposed final floor plan.

Additionally, we are digging into BLS data to compare already existing data.

It varies, but when retainage exists that will drive up the cash to continue to advance the project because borrower won't be receiving draw releases equal to their outlay. 

Point is, risk exists with ALL of it and there is no sure fire "guaranteed" anything.

What type of interview do you do with existing tenant(s) to ask them about maintenance issues?

Looking for guidance on options. new builds aren't hard to finance and I would argue they are preferred to existing fix and flip loans, especially if you have experience. banks look at your experience, your builder's experience, loan structure, permits, etc you need to get an experienced builder familiar with advanced underwriting and negotiations with local, regional, and national lenders. in columbus we do ground up construction for clients at a 20% discount so they can BRRRR out of the new build with equity and we have pages and pages of data on what we build and why and it's all supported by market statistics. 

I'm no appraiser but have plenty of fix and flips as well as new construction but IMO, it will be existing home. 

Can your existing box support the addition?