Mainly because of two things: (a) NPV and time velocity of money are countering strong objectives; (b) it's generally the safest time window to use for maximizing profits from an emerging market. 

If you invest $500k as a downpayment and pocket the $500k that is taxable.Always check with a CPA or speak with a 1031 specialist like Bill Exeter.

I see a lot of references to different classes of properties and was curious if there was some objective measure to make this determination or if it's more subjective 

Most pier and beam foundation homes can be leveled in a couple of days for less than $4,500 and a concrete pier foundation specialist can do the same for a slab on grade with the price getting up to maybe $7,500 depending on the extent of damage and number of piers needed.

I think this is a situation of learning, she's definitely not objecting to return the $500 but in principal wants to know who is in the right.

I don't want objectional people anyway.

Thanks Lucas, I did reach out to my pest control guy about the woodpecker and he sent me the information about ways to get rid of the bird by scaring it away (hanging flashing and other reflective object as well as covering holes with wire mesh). 

Let them call their own mold remediation specialist, and if that company finds something that is your responsibility you can deal with payment and costs from there. 

Consider adding storage space in the basement to remove that potential objection.

So there's pros and cons to either and my particular scenario and objectives will determine what's best for me.