The following link provides a joint statement by the United States Department of Justice and the Department of Housing and Urban Development regarding reasonable accommodations under the Fair Housing Act.  This statement provides in depth information, in a question and answer form, on the right to be provided with a reasonable accommodation in housing because of a disability.  This statement also provides some common examples of the types of accommodations that can be provided by a landlord, the rights of a tenant to make modifications to a property and under what circumstances an accommodation can be denied:  http://www.hud.gov/offices/fheo/library/huddojstatement.pdf