After stumbling upon the BP website and all of the resources available here, we are considering other methodologies that we had been oblivious to.

On a subordinate note you can also foreclose or get a reperformance but the methodology is different and risk is higher.

I have a 4-plex in Fort Worth and additional properties available right now across DFW to help in your BRRRR methodology.

Look at the contractors methodology/scope.

There are some people who are very well known in this niche and who offer coaching courses on their methodologies.

I would only ever recommend Guesty if you're a large PM using Trust Accounting methodology. 

I am interested in buy and hold residential (SFR and MF) using essentially a BRRRR methodology. 

There could be $100K worth of functional repairs that you'd never know about just looking at pictures.All that said, the BP book on estimating rehab costs is a great place to start (I'm the author, so perhaps I'm a bit biased) -- once you understand the methodology for how to estimate costs and the specific process, it gets much, much easier as you practice.

I research the investment, the management of the fund, educate myself on appraisal methodology, economic forecasting, etc.  

In 1977 they presented a joint paper describing a statistical methodology in risk assessment of lending to a particular consumer based on how the credit history of that consumer compared to the statistical norms of a large pool of consumer data in several key areas.