20 CFR §654.416

1. (a)Sleeping facilities must be provided for each person. Such facilities must consist of comfortable beds, cots, or bunks, provided with clean mattresses.
2. (b)Any bedding provided by the housing operator must be clean and sanitary.
3. (c)Triple deck bunks may not be provided.
4. (d)The clear space above the top of the lower mattress of a double deck bunk and the bottom of the upper bunk must be a minimum of 27 inches. The distance from the top of the upper mattress to the ceiling must be a minimum of 36 inches.
5. (e)Beds used for double occupancy may be provided only in family accommodations.