How to Sift through Properties for Rehabbing without seeing them?

[Tyler Haanen]

Location(s): Milwaukee, WI. Wauwatosa, WI. West Allis, WI.

Target strategy: House Hacking into BRRRR

I want to buy multifamily units that have the potential for forced appreciation, in solid neighborhoods. (B+ to C+ areas)

Secondary strategy: House Hacking into Flip (selling a turnkey rental property, after 1 year living requirement is met)

While I am not completely ready to invest (I am a full time student in my final semester), I am sharpening the toolbox so to speak by actively analyzing deals in my area (Milwaukee). The biggest roadblock for me personally, is trying to evaluate properties and their potential rehab costs. 

Calculating an ARV seems to be an easier task, because I can evaluate the sale prices of similar properties in the area, with respect to size, quality and location.

However, estimating rehab costs is difficult. I wonder how others decide whether they should spend any more time analyzing a property without ever going to the property and getting an accurate estimate of the rehab costs?

Or is it that you really have to come up with a rough estimate, see the property yourself, come up with a new estimate and potentially waste your time doing so, seeing that this property cannot make the numbers work? Are there some strategies here that I am missing in filtering through potential properties? 

Any thoughts, comments, suggestions are greatly appreciated!