I think my HELOC is ~2.5% (~1.5% for special xmas spend more promotion). To be pricks, they don't make the rate available online, you need to look at the mailed statements.
I cannot go to a different bank for HELOC as they pulled a 100% lien on my property. Even though max approved mortgage + HELOC is <<50% of current market value, on paper, there is no more secured credit available other than through mortgage bank.
If you're feeling confident, pull the mortgage and invest the money in reasonably safe dividend paying securities (for instance banks with net cost of borrowing ~zero). As you need money for projects, sell securities to generate project money.