In San Francisco a required rear yard is open ground the Planning Code creates and then closes. San Francisco Planning Code Section 134 sizes it, requires it at every story in the districts it names, and permits only the obstructions Section 136 lists. The California Building Code needs that same ground for a different job, sending a building's exits to the exterior, to grade and on to a public way. On a building with two or more dwelling units, the exterior access balcony that answers an upper-floor exit is written out of the paragraph permitting balconies, and the permitted stairway is capped in height, projection and extent. The state code's rating attaches to the replacement route, never to the rear yard.
Key numbers
| Figure | What it governs | Section |
|---|---|---|
| 30% / 25% of lot depth, min 15 feet | Basic rear yard size | Planning 134(c) |
| Six feet, 2/3 buildable width | Stair reach and extent, above three feet of grade | Planning 136(c)(14) |
| 44 / 36 inches, clear to 7 feet | Egress court width; 36 for Group R-3 and U | Building 1029.2 |
| Less than 10 feet wide | Rating trigger, measured across the court | Building 1029.3 |
| 10 feet above the court floor | How far up the 1-hour rating runs; openings there at three-quarter hour | Building 1029.3 |
| Occupant load under 10 | One of three exceptions | Building 1029.3 |
Section 134 creates the rear yard, then closes it
San Francisco Planning Code Section 134 sets the rear yard as a share of lot depth: in RH, RM-1, RM-2, RTO-1 and RTO-M Zoning Districts it is "equal to 30% of the total depth of the lot", in all other zoning districts 25%, never under 15 feet. Section 134(b) subordinates it to any Special Use District or Residential Character District. Section 134(d)(1) fixes where it sits, across a longer and different district list: "Rear yards shall be provided at grade level and at each succeeding level or story of the building."
Section 134(e) is the hinge.
Only those obstructions specified in Section 136 of this Code shall be permitted in a required rear yard,
and no other obstruction may be constructed, placed or maintained within it.
Section 136 is the list, and it prices what it permits
San Francisco Planning Code Section 136 carries that list. Two of its items decide most exterior-egress questions on a multi-unit building, each naming yards in its own sentence.
Section 136(c)(3) permits bay windows and balconies. "With respect to obstructions within yards and usable open space", it adds, the Paragraph (c)(2) versions are permitted as an alternative. Both paragraphs permit balconies "other than balconies used for primary access to two or more dwelling units" or to two or more bedrooms in group housing.
Section 136(c)(14) permits steps and "uncovered stairways and landings not extending higher than the floor level of the adjacent first floor of occupancy above the ground story", then caps them in yards at "extending no more than six feet into the required open area for any portion that is more than three feet above grade" and "2/3 the buildable width of the lot along a front or rear building wall".
Section 1028 sends the exits to grade and to a public way
California Building Code Section 1028 puts an egress problem on that ground. Section 1028.2 requires that "Exits shall discharge directly to the exterior of the building" and that "The exit discharge shall be at grade or shall provide a direct path of egress travel to grade." Section 1028.5 requires "a direct and unobstructed access to a public way". Section 1028.1 makes the next connection in the code's own words: "The exit discharge shall comply with Sections 1028 and 1029".
Section 1029 governs the route once it is an exit discharge component
California Building Code Section 1029 states its own condition of application: "Egress courts serving as an exit discharge component in the means of egress system shall comply with the requirements in this section."
The subject there is an egress court; a required rear yard is what Section 134 creates and Section 136 governs. Section 1029.3's trigger is a court's width; Section 134(c) sets the rear yard by lot depth. Nothing in either text connects those two measurements.
Where the cheaper lane is, and what it costs
The alternative is the route Section 1028.5 describes, one giving "a direct and unobstructed access to a public way" at grade, and Section 1029 prices it in the same breath. Section 1029.2 sets the floors: "the minimum width shall be not less than 44 inches (1118 mm)", 36 inches for Group R-3 and U occupancies, clear to 7 feet, never less than the required capacity. Section 1029.3 sets the charge: "Where an egress court serving a building or portion thereof is less than 10 feet (3048 mm) in width, the egress court walls shall have not less than 1-hour fire-resistance-rated construction for a distance of 10 feet (3048 mm) above the floor of the egress court", with opening protectives at not less than three-quarter hour in those walls. The two ten-foot figures differ: one is the trigger, measured across the court; the other is how high the rating runs.
Three exceptions follow, and any one removes the charge: egress courts "serving an occupant load of less than 10"; those "serving Group R-3"; and those "located at grade, that provide direct and unobstructed access to a public way through two or more independent paths", each path held to the required width or capacity, whichever is greater.
What this looks like on the drawing
On the rear elevation: an exterior access balcony, which Sections 136(c)(2) and (c)(3) write out, or an uncovered stairway stopped at the first occupied floor above the ground story and held to six feet of projection. On the wall section of the at-grade route: 1-hour fire-resistance-rated construction ten feet above the egress court floor, with three-quarter-hour opening protectives in those walls. Both belong to the replacement route, not to the rear yard.
Currency
Sections 134 and 136 come from the 2026-08 San Francisco Planning Code edition in GoCodebook's library, updated 2026-09-23. Both were last amended effective 3/16/2026 - Section 134 at division (d)(3) by Ord. 13-26, Section 136 at division (c)(30) by Ord. 10-26. Section 134 was also amended inside 24 months of October 2026 by Ord. 245-25, effective 1/12/2026, which amended divisions (b), (c)(1) and (d)(1)-(2) and added division (l), and by Ord. 297-24, effective 1/19/2025, which amended division (b). Divisions (b), (c)(1) and (d)(1) are read here, and the text quoted is the amended text as published; confirm the effective date before relying on it. Section 136's other amendments in that window, at (c)(23) by Ord. 146-25 and at (c)(24)(C) by Ord. 297-24, do not touch the items read here.
Sections 1028 and 1029 come from the 2025 California Building Code (Title 24, Part 2), 2025 edition, updated 2026-10-24, effective 2026-01-01 per its table of contents; neither carries the italics marking a California amendment. Title 24 prints no per-section history, so no amendment date for either was established here - nor was the edition of San Francisco's own building-code volume.
Frequently asked questions
Does the rated-wall charge reach a one- or two-family house?
Exception 2 to Section 1029.3 exempts egress courts "serving Group R-3" outright, and Exception 1 exempts those "serving an occupant load of less than 10". Section 1029.2 separately gives Group R-3 and U occupancies a 36-inch minimum width rather than 44 inches.
Can an exterior stair be built in a required rear yard?
Section 136(c)(14) permits steps and uncovered stairways and landings, capped three ways: in height at the floor level of the adjacent first floor of occupancy above the ground story, in projection at six feet into the required open area, and in extent at 2/3 the buildable width along a rear building wall.
Is the rear yard requirement absolute?
Section 134 routes exceptions, and this article stops at where it routes them: Section 134(g) allows "an exception to the rear yard requirements of this Section 134" in C-3 Districts, in accordance with the provisions of Section 309, on the light-and-air conditions it states.
Sources
- San Francisco Planning Code Section 134 - Rear Yards: https://gocodebook.com/library/us/ca/san-francisco-planning/article-1.2-dimensions-areas-and-open-spaces/sec.-134.-rear-yards-in-r-rc-rto-nc-m-cmuo-mug-muo-mur-red-red-mx-spd-umu-and-wmug#134
- San Francisco Planning Code Section 136 - Obstructions in required setbacks, yards and usable open space: https://gocodebook.com/library/us/ca/san-francisco-planning/article-1.2-dimensions-areas-and-open-spaces/sec.-136.-obstructions-over-streets-and-alleys-and-in-required-setbacks-yards-and-usable-open#136
- California Building Code Section 1028 - Exit Discharge: https://gocodebook.com/library/us/ca/ca-building-code/chapter-10-means-of-egress/section-1028-exit-discharge#1028.5
- California Building Code Section 1029 - Egress Courts: https://gocodebook.com/library/us/ca/ca-building-code/chapter-10-means-of-egress/section-1029-egress-courts#1029.3
Related reading: San Francisco Rear Yard Requirements, Explained: https://gocodebook.com/blog/sf-planning-code-134-rear-yard-requirements
Code text quoted as published in GoCodebook's library on 2026-09-13 and re-checked against the library on 2026-10-26. This article does not replace permit review or professional judgment.