Reasons why they don't close: 1. borrower doesn't tell the whole story 2. lender fails to ask questions 3. property in bad condition or C class and doesn't appraise for sale price 4. borrower believes it can rent for a lot more than the market shows 5. property weird/ancient crumbling/not habitable 6. title clouds...Here is what you need to start to work with for DSCR at many "shops":Loan amount above $110000, your mortgage FICO 680 middle, no forbearance/ no mortgage lates, market rent survey and rental agreement more than cover the PITI, you have a written quote for insurance, you have reserve money in your checking account, the down and closing costs are in your checking account, you have the vesting ready to go, property is not a rehab and is ready to rent, your lender broker has been in the business more than six years and can quote all the terms and ins and outs needed. 

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.

It’s an ancient argument to which sensible investors no longer subscribe.

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

Our methodology is B or C properties in A, B or C areas (slight value add).Key indicators we look for in our deals are (CCR = 10% or higher.....