If there's a child who lives in the unit who has an elevated blood level, even if it came from outside the unit, and you don't have the certificates, you're going to be target #1 and you won't be covered by insurance without the certificates.So just on that issue alone, yes, even if you have to put it on credit cards, I would get those new windows in, on all the units you're renting out.

It allows for the formation of separate “child” series under the “parent” Series LLC, but the liability is still compartmentalized within the individual “child” series in case there are any legal issues.

The difference is that you can continue building more “child” series to protect you other two (and potential future) properties - compartmentalizing them from you and each other.

The other limiting factor is that we have two children and child care is not cheap.

.- number of units (in the case of MF)- location of real estateThe investor has to decide what mix is optimal for their situation.If Series-LLC is an option for you, get one and put each property in its own child Series-LLC, problem solved.

@Trevor Finton the one thing I did not add  in relation to the Series LLC is to really know your states LLC Internal Liability Shields and judgment orders, and then how those relate to the individual child series of the Series LLC.

Or they have an adult child just out of prison for cooking meth, but with a job promised with adequate income, do you take him? 

For example, a single mother with a child that is asking about the safety of the building, who all would have a key, assigned parking, is there pest control provided would indicate to me this person is not concerned about getting approved or being able to pay the rent but rather what type of community is it for her and her child.

He had arrived the week before, was living in a hotel, and wanted to get into a place asap before wife and child arrived.

Which doctor are you going to take your child to?