In 1983, the Center for Study of Pre-Retirement and Aging at the Catholic University of America conducted a study of how accessory apartments work in practice for 198 elderly homeowners with accessory apartments, tenants of accessory apartments, and overhoused homeowners. The resultant report shows overall satisfaction among both tenants and homeowners, with 98 percent of the homeowners expecting to keep accessory apartments in their homes permanently, and 60 percent of tenants planning to stay in their apartments as long as possible. The principal reason for installing such an apartment was income, with security cited as a distant second. Nearly half of the homeowners were related to their tenants; 75 percent of the related tenants provided some services to the homeowner, but only 24 percent of unrelated tenants did so. The study concludes that the availability of voluntary or emergency assistance, and the added sense of security against criminal intrusion, have a tangible value, especially to older persons, and that there may be considerable scope for expanding service exchanges between homeowners and tenants, such as a reduction in rent in exchange for services. Apartments can also be sources of barrier-free housing and offer flexible use for a fixed asset. The impact on neighborhoods appears minimal, and, while lack of privacy was the most significant problem for homeowners, it was not considered especially serious. More than 70 tables show detailed responses to questions; an appendix provides the text of comments.