For ADU's - I've seen older posts on them being attributed limited value despite the additional sqft, bedrooms, bathrooms, etc. they add to the property, but the methodology seems to be geography specific.

Personally, I highly recommend the EOS methodology from the book Traction if you are looking to build some structure on the idea.

Also, keep in mind that same methodology applies to rental rates too.

Seriously, you need a proven methodology for “out of state” investing.

I'm also hoping to learn as much as possible related to the buy and hold methodology, BRRRR investing, financing, and anything else that may be applicable.

@Lee Ripma  The percentages can actually be higher than the estimates above with a quality, engineering-based study, the IRS' preferred methodology.

Additionally, different towns have different assessment methodologies and they can vary quite wildly. 

The IRS' preferred methodology is "engineering-based" and that is what we provide.

The NFIP has relied solely on maps and elevation certificates, however, the new methodology places homes in market “baskets”.

@Dave FosterI believe the condo thought process/methodology is correct in this case.