(a) Primary enclosures shall comply with all of the following structural standards:

1. (1) Primary and temporary enclosures shall be structurally sound and maintained in good repair to protect the animals from injury, to contain the animals, to keep other animals out, and to promote the health and well-being of the enclosed animals. Primary enclosures shall be constructed so they can be routinely maintained to allow animals to stay clean.
2. (2) The floor of the primary enclosure shall be constructed to prevent injury. A solid surface, platform, or shelf shall be provided when a grid-flooring system is used.
3. (3) Primary enclosures shall be constructed of materials that are impervious to moisture and can be sanitized.
4. (4) All primary enclosures shall provide adequate space for the animal or animals housed in the enclosure.
5. (5) Each primary enclosure shall provide animals with an enrichment device or devices appropriate for the species, age, size, and condition of the animal.

(c) In addition to the requirements set forth in subdivision (a), primary enclosures for birds shall be designed to ensure all of the following:

1. (1) A bird can fully extend both of its wings at the same time without contacting the sides of the enclosure.
2. (2) Perches are provided in a diameter that is appropriate for the species, age, size, and condition of the bird, and for the size of the enclosure.
3. (3) There is sufficient space to enable each bird to fully extend its wings in every direction while all birds are simultaneously perched.