Eric Burgoon, SVP of mortgage lending at Lake Michigan, said the 119,000-member credit union did not make any specific efforts to reach out to low or moderate income borrowers but because of their dedication to providing guaranteed, low mortgage rates, the loans have great appeal to all income groups, including low to moderate income purchases, he pointed out.

Because the credit union's field of membership includes low income areas, approving loans for members who live in these communities was also a matter of course.

Lake Michigan's low-income designation means that at least 50.1% of its membership has income that is less than 80% of median family income for its area, according to the NCUA and the Michigan Credit Union League.

The HMDA numbers bore out the focus on purchase loans which beat out refinances at Lake Michigan 55.23% to 43.28%, respectively, in 2013. A small number of the loans were used for improvements and renovations to existing properties.

Burgoon said Lake Michigan focused on building working relationships with Realtors and had been doing so for some time. Many of them know the credit union's reputation as a mortgage lender and its track record for closing loans on time.

"Our aim is to close the loan by the contract date," Burgoon said.  "Usually, that's 30 days or so, sometimes a little more or a little less."

The Realtors appreciated Lake Michigan's on-time performance, that in turn, has helped to build the credit union's mortgage portfolio, he added.

The HMDA data showed that 28.34% of Lake Michigan's mortgage loans in 2013 went to lower and moderate income borrowers, with 25.26% going to middle income members and 45.42% to upper income borrowers.