22 inches.
2013 California Plumbing Code
Shower doors shall open so as to maintain not less than a twenty-two (22) inches (559 mm) unobstructed opening for egress.
Should the shower need to be “accessible”, please refer to the following:
City of Los Angeles Department of Building and Safety,
Disabled Access Section
35. Showers required to be accessible shall comply with the following: (2014 Los Angeles Building Code 1134A.6)
a. When one or more shower stalls are provided within the same dwelling units, at least one shower stall shall comply with one of the following requirements:
i. The shower stall shall measure at least 42 inches wide by 48 inches deep with an entrance opening of at least 36 inches; or
ii. The shower stall shall measure at least 30 inches deep by 60 inches wide with an entrance opening of at least 60 inches. A water closet may project a maximum of 12
inches into the opening, provided that a minimum of 36 inches clear space is maintained between the water closet and the shower wall as illustrated in Figure 11A-9L; or
iii. Other shower stall configurations shall measure at least 36 inches deep by 60 inches
wide with an entrance opening of at least 36 inches when a wall is installed on the opening side.
Additional Information:
California Building Code 2014 Section 1210.2.3 Showers.
Shower compartments and walls above bathtubs with installed shower heads shall be finished with a smooth, nonabsorbent surface to a height not less than 70 inches (1778 mm) above the drain inlet.
