Over the last 15 years, there has been much innovation in finance to support housing and community development for low-income groups even though most governments and official aid agencies have paid little or no attention to this. Most of these schemes had savings as an important component. For some schemes, and for many households, savings is the only source of investment finance, as incomes are too low or uncertain to ensure loan repayments. Many of the largest and most effective financial schemes have been cases where the resources and capabilities of low-income households have been combined with the efforts of supporting local NGOs and local governments. In most urban areas in high-income nations and many middle-income nations, good quality, legal housing is expensive. Most of it would not have been built without mortgage finance; middle-income households, and even most upper-income groups, need mortgages in order to buy it, or long-term finance in order to build it. In most cities in Africa, Asia, and Latin America, low-income households cannot afford legal housing or good-quality housing. They either rent (usually in poor quality overcrowded dwellings) or buy or build in illegal settlements. They cannot get conventional housing finance because their homes are in illegal settlements and they lack the income or formal documentation that housing finance agencies require.