In a new San Francisco multifamily building, four rules are triggered by the same elevator, and not one of them counts the building the same way — so they do not move together. The California Building Code as adopted rates a shaft enclosure on the stories it connects, and it alone says what goes into that count. A second section sets hoistway-door protection on the stories a hoistway connects, and defines nothing. Chapter 11A counts no stories: its trigger is what the elevator serves, and a floor above grade can be deemed a ground floor. The San Francisco Planning Code counts feet against the district height limit, then holds the elevator penthouse to 16 feet no matter what that limit is.
Key numbers
| Figure | What it governs | Section |
|---|---|---|
| 2 hours | Shaft enclosure, four stories or more | § 713.4 |
| 1 hour | Shaft enclosure, under four stories | § 713.4 |
| Four stories | The break between them | § 713.4 |
| More than three stories | Hoistway-door protection | § 3006.2 |
| 16 feet | Elevator penthouse, any height limit | Sec. 260(b)(1)(B) |
| 20 feet | Other listed features, above 65 feet | Sec. 260(b)(1)(B) |
| 65 feet | Where 16 feet becomes 20 | Sec. 260(b)(1)(B) |
| 30% of the roof | The listed features together | Sec. 260(b)(1) |
What the shaft enclosure counts
California Building Code Section 713.4 rates the enclosure on the stories it connects: "Shaft enclosures shall have a fire-resistance rating of not less than 2 hours where connecting four stories or more, and not less than 1 hour where connecting less than four stories." It is the only rule in this chain that says what goes into its count.
The number of stories connected by the shaft enclosure shall include any basements but not any mezzanines.
What Section 713.4 does not do is tell any other section how to count; that sentence appears there alone.
What the hoistway rule counts
California Building Code Section 3006.2 turns on a different object, and defines nothing. It requires hoistway-door protection "where an elevator hoistway connects more than two stories" in buildings regulated by the Office of the State Fire Marshal, "and more than three stories for all other buildings." Among the conditions it lists is "Group R-1, R-2, R-2.1 and R-2.2 occupancies".
That threshold lands on the same integer boundary as the shaft enclosure rule, written about a different object: one counts the stories an enclosure connects, the other the stories a hoistway connects. Section 3006.2 states no counting rule.
Chapter 11A counts what the elevator serves
California Building Code Section 1106A.1 item 2 counts no stories. Its trigger is what the elevator serves: "When a building elevator or elevators are provided as a means of access to dwelling units other than dwelling units on a ground floor (see Section 1104A.2), the building is an elevator building." The same item adds: "All dwelling units become covered multifamily dwellings in that building."
Its own Note keeps the other case out: "Where a building elevator is provided only as means of creating an accessible route to covered multifamily dwelling units on a ground floor, the building is not considered to be an elevator building". The question is which units it serves, not how many stories it connects.
A ground floor need not be at grade
California Building Code Section 1104A.2 decides what a ground floor is for that trigger: "Where the first floor containing dwelling units in a building is above grade" … "This floor will be considered a ground floor". A level the code deems a ground floor is not one read off a building section, so Chapter 11A's measure cannot be derived from the others.
The Planning Code counts feet, then freezes one feature
San Francisco Planning Code Sec. 260(b)(1) holds the listed rooftop features to one area budget: their summed horizontal areas "shall not exceed 30% of the horizontal area of the roof above which they are situated". Sec. 260(b)(1)(B) names the list — "Elevator, stair and mechanical penthouses, fire towers, skylights, and dormer windows." — and sets one allowance: "limited to the top 16 feet of such features where the height limit is 65 feet or less, and the top 20 feet of such features where the height limit is more than 65 feet."
Then the same subsection writes the elevator out of the better half: "However, for elevator penthouses, the exemption shall be limited to the top 16 feet and limited to the footprint of the elevator shaft, regardless of the height limit of the building." No story count reaches that measure.
Where the cheaper lane is, and what it costs
On this roof the cheaper feature is everything listed except the elevator penthouse. A stair or mechanical penthouse beside it keeps "the top 20 feet" above a 65-foot limit, while the elevator penthouse is held to "the top 16 feet" and, in the same sentence, to "the footprint of the elevator shaft, regardless of the height limit of the building" — four feet of height given up on a taller building, a limit in plan its neighbours do not carry, and the same 30% roof-area budget, which "may be increased to 40% by unroofed screening".
What this looks like on the drawing
This chain ends on four drawn things: a shaft enclosure drawn as a one-hour or a two-hour assembly, on a count that includes the basement; hoistway-door protection drawn or not, on a different count; an accessible route drawn to the units the elevator serves; and a penthouse drawn to 16 feet and to the shaft's footprint.
Currency
The Building Code sections here are the 2025 California Building Code (Title 24, Part 2), 2025 edition, updated 2026-10-24. Title 24 sections carry no section-level ordinance history in this corpus, so the research did not establish an amendment date for Sections 713.4, 3006.2, 1106A.1 or 1104A.2.
San Francisco Planning Code Sec. 260 is quoted from the 2026-08 edition, updated 2026-09-23. Its most recent amendment, Ord. 245-25, took effect 1/12/2026 — inside 24 months, so confirm the effective date before relying on it. It amended division (a) and the height-measurement tables, not (b)(1)(B), whose language traces to Ord. 122-23, effective 8/5/2023, and Ord. 159-23, effective 8/28/2023. San Francisco's own building code volume in our library, 2026-08 edition, updated 2026-10-23, prints "No San Francisco Building Code Amendments" for Chapters 11A and 30, and its Chapter 7 amends Section 707.1 only, so it shows no local change to Sections 713.4, 3006.2, 1106A.1 or 1104A.2.
Frequently asked questions
Are the shaft rule and the hoistway rule the same three-or-four-story test?
They land on the same integer boundary and are written about different objects. Section 713.4 rates the stories a shaft enclosure connects and supplies its own counting rule. Section 3006.2 is written about the stories a hoistway connects — "more than three stories for all other buildings" — and states no counting rule.
Does an elevator make every dwelling unit in the building covered?
Not as stated. The trigger in Section 1106A.1 item 2 is what the elevator serves: access to "dwelling units other than dwelling units on a ground floor". Its own Note provides that an elevator "provided only as means of creating an accessible route to covered multifamily dwelling units on a ground floor" is not an elevator building.
Is there a route to more height for an elevator penthouse?
Sec. 260 writes one as a condition: the Zoning Administrator "may, after conducting a public hearing, grant a further height exemption for an elevator penthouse for a building with a height limit of more than 65 feet", and only where "required to meet state or federal laws or regulations". Where the height limit is 65 feet or less, Sec. 260 writes no further route.
Sources
- California Building Code Section 713.4 — Shaft enclosure fire rating: https://gocodebook.com/library/us/ca/ca-building-code/chapter-7-fire-and-smoke-protection-features/section-713-shaft-enclosures#713.4
- California Building Code Section 3006.2 — Hoistway door protection: https://gocodebook.com/library/us/ca/ca-building-code/chapter-30-elevators-and-conveying-systems/section-3006-elevator-lobbies-and-hoistway-opening-protection#3006.2
- California Building Code Section 1106A.1 — Elevator building: https://gocodebook.com/library/us/ca/ca-building-code/chapter-11a-housing-accessibility/section-1106a-site-and-building-characteristics#1106A.1
- California Building Code Section 1104A — Ground floors above grade: https://gocodebook.com/library/us/ca/ca-building-code/chapter-11a-housing-accessibility/section-1104a-covered-multifamily-dwellings#1104A.1
- San Francisco Planning Code Sec. 260 — Height limits, exemptions: https://gocodebook.com/library/us/ca/san-francisco-planning/article-2.5-height-and-bulk-districts/sec.-260.-height-limits-measurement#260
- San Francisco Building Code Chapter 7 — Local amendments: https://gocodebook.com/library/us/ca/san-francisco-building/chapter-7-fire-and-smoke-protection-features
- San Francisco Building Code Chapter 11A — Local amendments: https://gocodebook.com/library/us/ca/san-francisco-building/chapter-11a-housing-accessibility
- San Francisco Building Code Chapter 30 — Local amendments: https://gocodebook.com/library/us/ca/san-francisco-building/chapter-30-elevators-and-conveying-systems
Related reading: Shaft Fire Ratings in California Buildings: https://gocodebook.com/blog/cbc-713-4-shaft-enclosure-fire-rating
Code text quoted as published in GoCodebook's library on 2026-09-13 and re-checked against the library on 2026-11-01. This article does not replace permit review or professional judgment.