Is there a length of time prior to moving out & renting the unit that we should keep renovations within so we can argue that the upgrades were for rental purposes rather than personal in the case of an audit? 

Also, a bank is typically harder to bargain with if you had to extend the length of the loan or make smaller payments for a period of time due to financial hardships (always unexpected, but do happen!). 

@Samantha Klein  The length of rental history required depends on your bank. 

The length of a string depends on what you need it to do.

So, what's the market average length of tenancy in that specific asset class?

Find a way to increase income by $20 per unit per month with 20 units, and all of a sudden you're making the same added profits as if you purchased 2-3 more units. 2) What is the length and depth of your track record (how long have you been at it, how many units do you have)?

And if you become a Pro Member of bigger pockets (no, I don't work for BP) you have access to past webcasts that talk about this topic at length. 

Also remember sometimes  the length  is not an adequate source for how much work and effort was put into it as in many instances they must research existing case law

Also make sure that they use 3rd party vendors (arms length, competitive bidding) to do work, unless they can give you a better price in-house.

The book itself is about 22 mins in length (you receive only an audibook).