In San Francisco the open space beside a building is sorted twice, by two tests asking different questions, and the sorting — not the width — decides the rule. The California Building Code sorts by enclosure: a court is "bounded on three or more sides by exterior building walls". San Francisco Planning Code Section 140 sorts the same strip by type; its number does not grow with height. The Zoning Administrator's published interpretation of 140(a)(1) adds a second half to the side-yard test — the strip has to run the entire depth of the lot — and states that one failing either half "will be treated as an outer court" for that section's purposes.
Key numbers
| Figure | What it governs | Section |
|---|---|---|
| Three or more sides | Court, not yard | CBC § 202 |
| 25 feet wide | Qualifying side yard | SF § 140(a)(1) |
| Depth no greater than width | Outer court under 25 feet | SF § 140(a)(1) |
| 25 feet, every dimension | Inner court or space between buildings | SF § 140(a)(2) |
| 3 feet, plus 1 and 2 per story | Court width, growth | CBC § 1205.3 |
| 8 percent of floor area | Natural light glazing | CBC § 1204.2 |
| 10 footcandles at 30 inches | Artificial light | CBC § 1204.3 |
Which code is asking
California Building Code Section 202 sorts by enclosure: a court is "An open, uncovered space, unobstructed to the sky, bounded on three or more sides by exterior building walls or other enclosing devices", and a yard is "An open space, other than a court".
San Francisco Planning Code Section 140 asks which listed type the space is, requiring the required windows — a Housing Code term Section 140 borrows — of a room of at least 120 square feet to "face directly onto an open area of one of the following types". Type (a)(2) is an open area "no less than 25 feet in every horizontal dimension for the floor at which the Dwelling Unit in question is located".
Which openings the court rules are written for
California Building Code Section 1204.2.2 states its own condition: "Exterior openings required by Section 1204.2 for natural light shall open directly onto a public way, yard or court, as set forth in Section 1205." The duty attaches to the openings Section 1204.2 requires: "not less than 8 percent of the floor area of the room served". Section 1204.2.2 also excuses one opening: "Skylights are not required to open directly onto a public way, yard or court." That relief is the Building Code's own.
What changes when the building gets taller
California Building Code Section 1205.3 starts a court at "not less than 3 feet (914 mm) in width", then grows it: "For buildings more than two stories above grade plane, the court shall be increased 1 foot (305 mm) in width and 2 feet (610 mm) in length for each additional story."
San Francisco Planning Code Section 140(a)(2) does not move: its story clause — "for the floor at which the Dwelling Unit in question is located" — fixes where the dimension is measured, not how large it becomes. Growth is on the state side; the local number is flat.
Whether the strip runs the entire depth of the lot
San Francisco Planning Code Section 140(a)(1) accepts a "side yard at least 25 feet in width" and says nothing about one stopping short of the rear of the lot. The Zoning Administrator's published interpretation of 140(a)(1), "Exposure — Side Yard and Outer Court" (Effective Date 3/21), supplies the second half:
for purposes of this Section, it must be both at least 25 feet wide AND extend the entire depth of the lot.
One failing either half "will be treated as an outer court". The scope travels with it — a published document about Section 140, not a general San Francisco definition of a side yard. That lands it in Section 140(a)(1)'s proviso: "if such windows are on an outer court whose width is less than 25 feet, the depth of such court shall be no greater than its width".
Where the cheaper lane is, and what it costs
California Building Code Section 1204.1 prints the alternative inside the requirement itself: "Every space intended for human occupancy shall be provided with natural light by means of exterior glazed openings in accordance with Section 1204.2 or shall be provided with artificial light in accordance with Section 1204.3." Section 1204.3 is the price — "an average illumination of 10 footcandles (107 lux) over the area of the room at a height of 30 inches (762 mm) above the floor level" — against Section 1204.2's "not less than 8 percent of the floor area of the room served". Read them together: the election is priced in footcandles, while San Francisco Planning Code Section 140 states a dimension and names its exceptions by section number.
What this looks like on the drawing
It lands on one rectangle and one window: a width, a depth, where that depth stops relative to the rear property line, and the window facing it from a room of at least 120 square feet. Two of those four questions are settled before anything is dimensioned.
Currency
- San Francisco Planning Code Section 140 — 2026-08 edition, updated 2026-09-23. Division (a)(2), the paragraph this turns on, was last amended by Ord. 248-23, effective 1/14/2024; the section by Ord. 62-24, effective 4/28/2024. Neighboring Section 140.1 was repealed by Ord. 245-25, effective 1/12/2026 — the one item inside 24 months of September 2026. Confirm the operative version before relying on the retrieved text.
- Zoning Administrator Interpretations — 2026-08 edition; the entries carry Effective Date 3/21; no amendment history or updated date was established.
- California Building Code Sections 202, 1204 and 1205 — 2025 edition (Title 24, Part 2), updated 2026-10-19. State code with no ordinance-history line: an edition, no amendment date.
Frequently asked questions
Where does the whole-lot-depth requirement come from?
Not from Section 140's own text, but from the Zoning Administrator's published interpretation of 140(a)(1), "Exposure — Side Yard and Outer Court" (Effective Date 3/21): "for purposes of this Section" a side yard must be "at least 25 feet wide AND extend the entire depth of the lot".
If artificial light is elected, do the court rules fall away?
Two sentences sit side by side; this article does not adjudicate between them. Section 1204.2.2's duty runs to "Exterior openings required by Section 1204.2 for natural light". Section 1205.1's scope runs to "yards and courts adjacent to exterior openings that provide natural light or ventilation".
Can the requirement be waived?
Section 140 names its routes by section number. Subsection (a)(3) routes Commercial to Residential Adaptive Reuse to Section 210.5. Subsection (b)'s group-housing requirement "may be waived by the Zoning Administrator per Section 307(m) of this Code". Subsection (c)(1) sends historic buildings and nonconforming-use conversion to "Sections 307(h) and 329", which "does not apply to new additions to historic buildings". Subsection (c)(2) sends Accessory Dwelling Units to Sections 307(l) and 207.1.
Sources
- San Francisco Planning Code 140 — Dwelling units face an open area: https://gocodebook.com/library/us/ca/san-francisco-planning/article-1.2-dimensions-areas-and-open-spaces/sec.-140.-all-dwelling-units-in-all-use-districts-to-face-on-an-open-area#140
- California Building Code 202 — Definitions: court, yard: https://gocodebook.com/library/us/ca/ca-building-code/chapter-2-definitions/section-202-definitions#202
- California Building Code 1204 — Lighting: https://gocodebook.com/library/us/ca/ca-building-code/chapter-12-interior-environment/section-1204-lighting#1204.2
- California Building Code 1205 — Yards or courts: https://gocodebook.com/library/us/ca/ca-building-code/chapter-12-interior-environment/section-1205-yards-or-courts#1205.3
- San Francisco Planning Code Interpretations 140(a)(1) — Exposure: side yard, outer court: https://gocodebook.com/library/us/ca/san-francisco-planning-interpretations
Related reading: Minimum Room Size in San Francisco, Explained: https://gocodebook.com/blog/minimum-room-size-in-sf
Code text quoted as published in GoCodebook's library on 2026-09-13 and re-checked against the library on 2026-10-21. This article does not replace permit review or professional judgment.
