There are HELOANs which are second position loans that you can use, typically 30 year fixed.

Also as you say whether the construction loan is possible this way I'm not too sure.

are they getting an sba loan ? 

@Eyong Agbortogo Estoppel agreements are used to clarify things like if the tenant has a security deposit, what they pay in rent, if they are month to month or under the impression they are on some type of annual agreement.

Then when I perform a good % of the work that we got paid full price for in the loan that's backed by asset being acquired. 

I did switch to one of those (not going to say publicly for privacy & security).Uploading data or settings from Mint is going to be a very tall order.

Financed $120k (80% LTV) at 8.5%, 30 year with no secured loan (not a heloc).  

Also, does the small amount not paid into self employment tax have any real effect on social security payments?

At that point I'd just be banking on the loan paydown and hoping for appreciation. 

conventional investment loan