Cal. Civ. Code § 187

  § 187. Egress. 1. Except as provided in paragraph g of subdivision
three of section one hundred seventy-one, egress from every apartment on
each story shall be provided as follows:
  a. If a dwelling is two stories or less in height, or if it is three
stories including a basement in height and conforms to the conditions of
subdivision four of section one hundred seventy-seven, a single means of
egress from each story to the street shall be sufficient.
  b. Every other dwelling shall have either two independent means of
egress or one means of egress equipped with a sprinkler system.
  c. At least one means of egress shall be a stair extending to and
through the roof by a bulkhead, except that a scuttle may be used in
lieu of a bulkhead if the dwelling does not exceed a basement and three
other stories in height, or if it does not exceed a basement and four
other stories in height and is occupied by not more than two families on
any story, and except that no bulkhead or scuttle, or stair or ladder
leading thereto, shall be required where the roof is a peak roof with a
pitch of more than fifteen degrees.
  d. Whenever a second means of egress is required, it shall, except as
provided in paragraph f, extend from the entrance story to the roof, and
shall be located eight feet or more from the first means of egress
unless separated therefrom by a public hall or elevator vestibule. Such
second means of egress shall be directly accessible at each story to
each apartment without having to pass through the first means of egress.
  e. A required second means of egress shall be either a system of
outside fire-escapes, constructed and arranged as provided in section
fifty-three for fire-escapes erected after April eighteenth, nineteen
hundred twenty-nine, a fire-stair, a fire-tower or a connection with an
adjoining dwelling as provided in paragraph f below.
  f. If the department upon the application of the owner shall deem it
feasible and so permit, the owner shall provide, and at all times
maintain unobstructed, a first means of egress extending by means of a
stair from the street through a bulkhead to the roof and thence from the
roof of such dwelling to the roof of an adjoining dwelling and through
such adjoining dwelling to the street and a second means of egress from
each apartment to a room on the same story or level in an adjoining
dwelling by means of a balcony. Every such balcony shall comply with the
requirements for a fire-escape balcony, except that its minimum clear
width shall be two feet instead of three feet. If at any time such
access to the street shall in the opinion of the department be
obstructed or be otherwise unsafe the department shall revoke the
permit, and upon such revocation the owner shall provide one of the
other types of egress permitted in this section.
  g. When the department shall find it impractical to erect an
independent fire-escape and shall refuse to permit egress by means of
balconies to an adjoining dwelling, the department may permit the
erection or use of a fire-escape to which the occupants of such dwelling
have safe, unobstructed access in common with the occupants of an
adjoining dwelling.
  h. Where a required means of egress leads to a yard less than thirty
feet in depth, except as provided in paragraph f of subdivision four of
section one hundred seventy-seven, there shall be access from such yard
to the street through a court or fireproof passage, or to the yard or
court of adjoining premises by a gate or door through an intervening
fence, or, if the department deems such gate or door impracticable and
so certifies, by a ladder to the top of an intervening fence or wall or
by such other means as the department may require.
  2. Where a sprinkler system is required such system shall be equipped
on each story with one or more automatic sprinkler heads with fusible
struts which shall be constructed to fuse at a temperature not higher
than one hundred sixty-five degrees Fahrenheit and all of which shall be
constructed, located and arranged in every stair and entrance hall, and
in every closet opening therefrom, in such manner as the department may
require. Such system may be attached to the city water supply main if
the normal minimum pressure thereon, measured in pounds per square inch
at the street level at the point of connection with said main, is not
less than the number of stories in the height of the dwelling,
multiplied by five, plus fifteen. If such normal minimum pressure is
less than the required amount or such system is not attached to the city
water supply main, it shall be supplied with water from a tank located
on the roof of the dwelling of such capacity and construction as the
department may deem necessary.  Such sprinkler system shall be
maintained continuously in good repair and serviceable condition.