A project in Kentucky aims to show how home lending can build wealth.

Homeownership is a crucial part of a family’s ability to build wealth: A home is the largest asset for most American families, and the value it can gain over decades can be tapped during retirement or left to the next generation.

But the share of Black households that own homes has only inched upward over the past 50 years, and the continuing homeownership gap is one of the main reasons the net worth of white households far exceeds that of Black families. One reason for the gap: the dearth of mortgages in communities where home prices are so low that most banks and lenders will not bother writing mortgages for them.

Now a new program in Louisville, Ky., called the MicroMortgage Marketplace project, which officially started two weeks ago, hopes to demonstrate how to increase the availability of small-dollar mortgages. Coordinated by the Urban Institute, a Washington think tank, the program hopes to become a demonstration project that can be replicated in other cities where modest homes are plentiful but the mortgages to buy them are in short supply.