In general, an additional insured is added when the additional party carries some of the risk related to the insured property."  

So I carry effectively 0 debt. 

However, longer-term bonds (1-5+ years) are subject to interest rate volatility:If rates rise, bond values drop, potentially leading to negative net returns.If rates fall, bonds appreciate, but gains are capped by their fixed coupon rates.While Treasuries provide stability, they offer limited upside and carry hidden risks for medium- to long-term maturities.Why Real Estate Is a Stronger Option in Today’s MarketMultifamily real estate, particularly value-add properties, presents an asymmetric risk-reward profile that Treasuries simply cannot match.

I tried to get the owner of three of the houses to carry a short note but no dice.

Part of the motivation for congress writing Dodd Frank was to clamp down on the investors offering preditory terms re  rent to own and seller financing and that view has carried into craigslist rent to own adds and you say zillow. 

This would allow for a longer carry back with up front cash flow.

As for holding a home and building another one - be sure to include carrying costs of the first home while building the second.  

Investment loans generally carry high down-payments and costs.

I am definitely open to seller financing, I just wanted to have a back up plan if we decide on this route and we cannot find a seller willing to carry  

 @Kobe Carr I haven't seen prices take a significant drop.