"Mortgage rates hit lower-than-anticipated levels in June, averaging a remarkable 5.23 percent," said Kent Conine, president of the National Association of Home Builders (NAHB). "For many who had been considering a home purchase, the incentive to lock in those rates was just too great to pass up."

For the first half of this year, the average pace of new-home sales was running 11 percent ahead of the pace set in the same period last year, according to the report. Sales of new homes rose in every region in June, with the largest increase - more than 32 percent - reported in the Northeast, and gains of 9.8 percent and 2.7 percent in the Midwest and West, respectively. The South posted a nearly 1 percent gain.