24 C.F.R. § 100.10

(a) This part does not:

(1) Prohibit a religious organization, association, or society, or any nonprofit institution or organization operated, supervised or controlled by or in conjunction with a religious organization, association, or society, from limiting the sale, rental or occupancy of dwellings which it owns or operates for other than a commercial purpose to persons of the same religion, or from giving preference to such persons, unless membership in such religion is restricted because of race, color, or national origin;

(2) Prohibit a private club, not in fact open to the public, which, incident to its primary purpose or purposes, provides lodgings which it owns or operates for other than a commercial purpose, from limiting the rental or occupancy of such lodgings to its members or from giving preference to its members;

(3) Limit the applicability of any reasonable local, State or Federal restrictions regarding the maximum number of occupants permitted to occupy a dwelling; or

(4) Prohibit conduct against a person because such person has been convicted by any court of competent jurisdiction of the illegal manufacture or distribution of a controlled substance as defined in section 102 of the Controlled Substances Act (21 U.S.C. 802).

(b) Nothing in this part regarding discrimination based on familial status applies with respect to housing for older persons as defined in subpart E of this part.

(c) Nothing in this part, other than the prohibitions against discriminatory advertising, applies to:

(1) The sale or rental of any single family house by an owner, provided the following conditions are met:

(i) The owner does not own or have any interest in more than three single family houses at any one time.

(ii) The house is sold or rented without the use of a real estate broker, agent or salesperson or the facilities of any person in the business of selling or renting dwellings. If the owner selling the house does not reside in it at the time of the sale or was not the most recent resident of the house prior to such sale, the exemption in this paragraph (c)(1) of this section applies to only one such sale in any 24-month period.

(2) Rooms or units in dwellings containing living quarters occupied or intended to be occupied by no more than four families living independently of each other, if the owner actually maintains and occupies one of such living quarters as his or her residence.