Two things have to be settled before this question has an answer: which district "R3" means, and whether Floor Area Ratio applies to what you are building at all.
"R3" is not a San Francisco district
The San Francisco Planning Code has no district called R3. It has three that get shortened that way, and they carry different limits:
| If you mean | Basic FAR limit under Table 124 |
|---|---|
| RH-3 — Residential House, Three-Family | 1.8 to 1 |
| RM-3 — Residential Mixed, Medium Density | 3.6 to 1 |
| RC-3 — Residential-Commercial, Medium Density | grouped with RM-3 at 3.6 to 1 |
A figure quoted for "the R3 district" without saying which one is not a usable number.
For a dwelling, the limit does not apply
Whichever of the three you are in, Section 124(b) removes the question for residential use:
In R, RC, NC, and Mixed Use Districts, Floor Area Ratio limits shall not apply to Residential Uses. However, projects proposing new construction of a Dwelling Unit that would exceed the maximum dwelling unit size described in Section 207.10 may require Conditional Use authorization by the Planning Commission as set forth in Section 207.10.
— § 124(b), San Francisco Planning Code
All three districts above are R or RC districts, so Table 124's figure does not reach a dwelling. That used to be the end of the answer. Since 12 January 2026 it is not: Section 207.10 caps an individual Dwelling Unit at 4,000 square feet of Gross Floor Area or a Floor Area Ratio of 1.2:1, whichever is greater. Table 124's basic FAR still governs the uses that remain subject to it.
Section 207.10: the cap that replaced the question
Ordinance 245-25 added Section 207.10, Maximum Dwelling Unit Size, effective 12 January 2026. It is the provision that gives San Francisco a residential floor-area figure again, and it is not in Table 124.
Any project that meets one or more of the criteria in subsection (b) shall be restricted to a maximum Dwelling Unit size of 4,000 square feet of Gross Floor Area or an equivalent Floor Area Ratio for any individual Dwelling Unit of 1.2:1, whichever is greater…
— § 207.10(c), San Francisco Planning Code
Who it applies to. Projects with a Development Application filed after 31 January 2026 that propose new dwelling units (including replacing a unit being demolished), the merger of two or more units, or a reduction in the number of units. An existing house nobody is altering is not caught by it.
The two figures, and which one wins. The cap is the greater of 4,000 square feet and a 1.2:1 ratio — so on a small lot the 4,000-square-foot figure is the one that governs, and on a large lot the ratio is. The two are equal at a lot of about 3,333 square feet; that arithmetic is ours, not the Code's.
Exceptions for multi-unit projects. A new-construction project of four to nine units may have one unit over 4,000 square feet; a project of ten or more may have up to 10% of its units over it.
Over the cap? That is not a prohibition. Section 207.10(d) treats a non-compliant project as one needing Conditional Use authorization from the Planning Commission, judged against the criteria in § 207.10(e) and § 303(c).
What counts toward Gross Floor Area. Section 207.10(f) uses the § 401 definition, excludes shared and common areas in multi-unit buildings and non-contiguous accessory storage — and includes every expansion permitted in the previous ten years, plus any construction done without a valid permit whenever it happened.
Normandie Terrace
Normandie Terrace is not a named district, overlay or special use district in the Planning Code, so it carries no FAR of its own. It is a street and neighbourhood name; the controls that apply come from the zoning district the lot actually sits in, plus any special use district or area plan mapped over it. Look the parcel up on the city's zoning map rather than searching the Code for the neighbourhood name.
How a "maximum" is actually assembled
Section 123 is the provision that defines the maximum, and it is not simply the number in Table 124. The maximum equals the district's basic FAR plus whatever premiums and floor area transfers apply, then restricted by several other subsections:
The maximum floor area ratio for any building or development shall be equal to the sum of the basic floor area ratio for the district, as set forth in Section 124, plus any premiums and floor area transfers which are applicable to such building or development under Sections 125, 127, 128 and 128.1 and as restricted by the provisions of Sections 123(c) and (d) and 124(b) and (j).
— § 123(a), San Francisco Planning Code
So a figure quoted without saying whether it is the basic limit or the maximum after premiums is ambiguous even when the number itself is right.
What shapes a residential building instead
Because § 124(b) takes FAR out of the picture for dwellings, the controls that decide how much can be built on an R or RC lot are dimensional:
- Height, measured under Section 260 against the limit on the Zoning Map, with Section 261 imposing further limits on dwellings in certain RH districts.
- Rear yard under Section 134, written to protect the mid-block open space behind a San Francisco block.
- Front setback under Section 132, related to the setbacks of the adjacent buildings rather than to a fixed dimension.
- Minimum lot width and area under Section 121, which applies citywide whatever the district or use.
- Dwelling unit density under Section 207, taken from the Zoning Control Table for the district.
Those are read off the Zoning Map and the district's Zoning Control Table, which is why the parcel — not the district name — is where this question gets answered.
Before you rely on a number
Section 124(a) allows the Zoning Control Table for a district to specify its own basic FAR, and Sections 125 through 128.1 add premiums and floor-area transfers on top of the basic limit. Confirm the parcel's district, height and bulk district, and any special use district with San Francisco Planning.
Code references: Sections 102, 123, 124 (including 124(b)), 207, 207.10 and 401, San Francisco Planning Code. Section 207.10 was added by Ordinance 245-25, approved 12 December 2025, effective 12 January 2026.
