You can bill friends/family while temporarily staying with them only if you can ensure the following:

(A) The lessor is in the business of renting property and the property involved is rented regularly.

(B) The rental income is claimed by the lessor as income and reported to the IRS.

(C) The transaction is an arm’s length between the employee and the lessor ‐ e.g. a lease is signed no different than that of other tenants (a regular business transaction). Refer to question 34760 at CGFS Knowledge base for more on this topic.