Purchasing a new construction home. Is it absolutely mandatory that we purchase an owners title insurance policy at this time??

Owners policies aren't required to borrower money for your home, just a lenders policy. Both policies protect in similar ways, but the owner's policy protects you and the lender's policy protects the lender against any defects in title that may come-up. I know many builders won't pay for an owner's policy so it's really up to you as to whether or not to spend your money on one. If you feel comfortable that the builder is on the up-and-up and nothing is going to arise a year from now due to the previous owner of the property (the builder) than you can forgo spending this extra. It all comes down to how much risk you are willing to accept.

Cory is right on.