Heritage Square, the 10-unit senior apartment complex in Mercer, filled up within a month of being available, and has 15 people on a waiting list.

Mercer County Housing Authority believes those facts will help it secure funding to build another 10 apartments on the same site.

Working with Trek Development of Pittsburgh, the authority will make Friday's deadline to apply to the Pennsylvania Housing Finance Agency for the majority of the funding, said authority Executive Director L. DeWitt Boosel.

The project's budget is $1,030,241, and the authority board agreed Wednesday to put up $206,148 in the form of a 40-year loan. The rest would come as tax credits that investors buy in return for credits on their federal income taxes.