If a faculty member anticipates that there will be a need to provide accommodations they can include expected costs in the grant proposal budget. If accommodation requests arise after the grant has been funded, the proposed budget can generally be reduced in other areas in order to cover accommodation costs. The funding source can be contacted for details about their policies.
Many campuses have a grant assistance office where there is guidance in this area. Faculty members can also contact funding sources directly for information. Some resources are available online. For example, the United States Department of Education (DOE) maintains a website called EDGAR that describes administrative regulations relating to DOE grant money expenditure. The National Science Foundation (NSF) offers their Policy Site online.