Good evening,Looking to connect with others in the real estate and mortgage space. 

We rent out our previous home and bring in $600 a month on it after mortgage, taxes, and insurance, but she doesn't see it as an investment property and so it has been hard to continue investing without her support.

I did my due diligence properly before doing business with them.

I think $50k is too shy for Boston proper zip codes unless you're OK in a smaller multi family.

In a perfect world, I would be able to command a rent high enough to at least earn 0% on the house to pay down the mortgage.

But not pull the equity to pay off mortgages just yet.

First, there is no institutional lender that I know of that would touch doing a HELOC behind a mortgage that did not belong to the borrower.

I am getting only 1.5% returns without taking into account the equity building portion.Mortgage tax write off is 0 as I currently pay mortgage on my primary residence.I have used this property as my primary home for 2 years in last 5 years.

Back to finance question, would it be a better decision to take the funds from the sale of the 2 acre lot and pay off the current mortgage (~$150k) and live in the current home for a year or so (in hopes that interest rates will go down) then refinance that take out $400k from equity (~$750k) to build new house? 

Then, you'll know whether precautions and proper cleanup procedures are required.Hope this helps.