Habitat builds and renovates simple, decent houses with the help of homeowner (partner) families, volunteer labor and donations of money and materials. These houses are sold to partner families at no profit and financed with affordable loans. The monthly homeowner mortgage payments are deposited into the revolving "Fund for Humanity," which in turn is used to build still more houses.   Habitat accomplishes its mission at the community level, through local affiliates based throughout the world. These affiliates raise funds to build houses, and some receive Habitat subsidies. All affiliates are asked to “tithe” – to give 10 percent of their contributions to fund house-building work in other nations. Habitat is not a giveaway program. In addition to a down payment and the monthly mortgage payments, homeowners invest hundreds of hours of their own labor – “sweat equity” – into building their Habitat house and the houses of others. How are partner families selected? Selecting a partner family is one of the most important challenges of local Habitat affiliates. Making a just and accurate decision during the process could mean the difference between success or failure, both for the partner family and the local affiliate. Decisions are based on the following criteria: Necessity Capacity to repay the loan Willingness to become partners with Habitat