San Mateo | Parking, Setbacks and Height
San Mateo, California Parking, Setbacks and Height: R1 Yards, the Daylight Plane, Floor Area Ratio, Apartment Yards, Downtown Bulk Rules and Parking Ratios
These are the rules that decide how large a building can be on a San Mateo lot and how many parking spaces it needs. A setback, which the code calls a yard, is the open distance a building must keep from a property line. The house rules are in Chapter 27.18, the apartment rules in Chapter 27.22, and the parking rules in Chapter 27.64. Height limits for apartment and mixed-use buildings come from the General Plan and are on the Measure T and height limits page. The San Mateo overview has the summary.
San Mateo yards, height and parking in six facts
- An R1 house may be 24 feet high to the plate line and 32 feet to the highest point of the roof, measured from existing grade. Source: Zoning Code 27.18.050
- The R1 front yard is 25 feet in R1-A and 15 feet in R1-B and R1-C, with 20 feet to a garage in R1-B and R1-C. Source: Zoning Code 27.18.070
- No R1 structure may extend above a daylight plane that starts 12 feet high at each side property line and slopes into the parcel at 45 degrees. Source: Zoning Code 27.18.050
- A house under 3,000 square feet needs 2 garage spaces, and an apartment outside downtown needs 1.5 to 2.2 spaces by bedroom count, visitor parking included. Source: Zoning Code 27.64.160
- An R3 building needs a 15-foot front yard, a 15-foot rear yard and 6-foot side yards at one and two stories, and the yards get larger with height. Source: Zoning Code 27.22.070 to 27.22.090
- Downtown, the parking in-lieu fee in the Central Parking Improvement District is $61,661.54 per space for July 1, 2026 to June 30, 2027. Source: Development Fees summary, revised July 1, 2026
R1 Houses: Yards, Height and Floor Area
| Standard | R1-A | R1-B and R1-C |
|---|---|---|
| Front yard | 25 ft | 15 ft; 20 ft to a garage |
| Interior side yard | 7 ft | 5 ft |
| Street side yard, ground floor | 15 percent of lot width, at least 7.5 ft and no more than 25 ft | 15 percent of lot width, at least 7.5 ft and no more than 15 ft |
| Street side yard, above the first story | 10 ft minimum | 10 ft minimum |
| Street side yard, garage | 20 ft minimum | 20 ft minimum |
| Rear yard | 15 ft; 25 ft for new construction above a single story | 15 ft; 25 ft for new construction above a single story |
| Height | 24 ft to the plate line; 32 ft to the highest point of the roof | The same |
| Floor area ratio | 0.4, plus 0.2 on parcel area over 10,000 sq ft | 0.5, plus 0.2 on parcel area over 6,000 sq ft |
Source: San Mateo Zoning Code, 27.18.050, 27.18.060, 27.18.070, 27.18.080 and 27.18.090.
- Height. "The maximum height of structures shall be 24 feet measured from existing grade to the building plate line and 32 feet measured from the existing grade to the highest point of the roof." The code defines the plateline as "the line established by the horizontal girder which supports the trusses or rafters of a roof."
- Rear yard. "A rear yard of not less than fifteen (15) feet shall be provided; a rear yard not less than twenty-five (25) feet shall be provided for new construction above a single story."
- Private roads. A building on a lot that fronts a private road or easement keeps "a front setback of at least fifty (50) feet from the centerline of such private road or easement."
- Floor area. "In no case shall more than 6,000 square feet of total floor area be permitted per parcel in residential use." In R1 the count includes detached garages, sheds and covered patios, and a room with a ceiling of 15 feet or more counts twice. "the first 100 square feet of a covered front porch shall not be included as floor area."
- No coverage percentage. Chapter 27.18 sets no lot coverage percentage for the house. Floor area ratio, yards and the daylight plane set the size. The one coverage rule is that "Accessory buildings shall not occupy more than fifty (50) percent of a required rear yard."
- Extending an old wall. Where an existing side yard is smaller than the rule, a one-story addition may continue the wall if the yard is at least 3 feet, the wall is no higher than 12 feet to the plate line, the extension is no longer than 20 feet, and the Zoning Administrator approves a site plan and architectural review.
The Daylight Plane
The code defines a daylight plane as "an inclined plane, beginning at a stated height above grade and extending into the site at a stated upward angle to the horizontal." A building must stay under it. Section 27.18.050 says "No structure shall extend above or beyond a daylight plane having a height of twelve (12) feet at each side property line and extending into the parcel at an angle of forty-five (45) degrees." By VanPlex arithmetic, a wall 5 feet from the side line may be 17 feet high under the plane, and a point 10 feet from the line may be 22 feet high.
- Small features. Antennas, chimneys, flues, eaves and skylights may cross the plane.
- Dormers. Their total length "shall not exceed a combined total of fifteen (15) feet on each side."
- Gables. Their total length "shall not exceed a combined total of eighteen (18) feet on each side."
- Raised floors. Where the first floor of an existing house is more than 3 feet above grade and is being extended, "the initial height of the daylight plane shall be fourteen (14) feet."
- Sloping parcels. Where the parcel slopes 15 percent or more between its side lines, the plane starts at 14 feet "on the downhill side of the parcel."
The same plane governs two-family homes in R2 and Nonexempt ADUs. For a detached accessory building in the rear third of an R1 lot the plane is lower, 9 feet "at each side and rear property line," and the building is limited to 9 feet to the plate line and 16 feet to the roof peak.
Driveways, Paving and What May Sit in a Yard
- Front yard paving. In R1, paving in the front setback is limited to driveways and walkways. A single-car garage may have paving "17 feet maximum in width or 40% of the street frontage, whichever is less," a garage for two or more cars "20 feet maximum in width," and a walkway 5 feet or less.
- Garage doors. For a garage within 50 feet of a street, "no more than fifty (50) percent of the ground floor building facade facing the street shall be composed of garage doors or open covered parking facilities."
- Driveway width. Section 27.64.025 says driveways "may not be less than 10 feet wide when serving two (2) or fewer garage or parking spaces, and not less than 12 feet wide when serving three (3) or more," and "Residential driveways shall not exceed 20 lineal feet in width."
- Projections. Eaves may project up to 3 feet or half the yard width, whichever is less. Chimneys, bay windows, balconies and decks may project 2 feet if they stay 3 feet from the property line. A covered front porch may project 2 feet into the front yard.
- Decks. Uncovered decks of 18 inches or lower are allowed in every required yard. Decks between 18 and 30 inches must stay 5 feet from property lines.
- San Mateo Park. In the San Mateo Park planning area, Section 27.18.115 sets a 50-foot front setback for a garage whose doors face the street, side yards of 10 feet on interior lots 75 feet wide or more, and 25-foot setbacks on both street frontages of a new house on a corner lot of that width.
R2 Two-Family Homes
Chapter 27.20 borrows from R1. "All regulations of the R1-B district, as to yard areas, shall apply to two family dwellings," and "All regulations of the R1 district, as to height and daylight plane, shall apply to two family dwellings." The floor area ratio is 0.6, or 0.5 on parcels up to 7,500 square feet in the Central and North Central neighborhoods. A detached accessory building may not sit in front of the main building and must be at least four feet from any other building on the lot. Parking follows the multiple-family row of the parking table, which names two-family homes.
R3, R4 and R5 Apartment Buildings
The yards for multiple-family buildings are in Sections 27.22.070 to 27.22.090, and R4 and R5 say "the regulations in the R3 district shall apply." The yards get larger as the building gets taller and as it is closer to house lots.
| Yard | Base rule | Taller buildings | Next to R1 or R2 |
|---|---|---|---|
| Front | 15 ft | More than three stories: one-half the height of the building | Front abuts an R1 or R2 parcel: the building height or 15 ft, whichever is greater |
| Side | 6 ft on each side for one and two story buildings | More than two stories: one-half the height of the building, to a maximum of 25 ft | Side abuts an R1 or R2 parcel: one-half the height or 15 ft, whichever is greater |
| Street side on a corner | 7.5 ft for one and two story buildings | More than two stories: one-half the height, to a maximum of 25 ft | No separate rule |
| Rear | 15 ft | More than three stories: one-half the height, to a maximum of 25 ft | Parcel abuts an R1 or R2 parcel: equal to the building height |
Source: San Mateo Zoning Code, 27.22.070, 27.22.080 and 27.22.090. A special use permit may set a different yard for a taller building.
- How stories are counted. Section 27.04.445 says that when a yard depends on stories, "the required yard shall be the building height divided by the story interval of 13 feet," and a fraction counts as another story.
- How height is measured. Section 27.04.080 measures "from existing grade at any point along the perimeter of a building, to the highest plate line of the structure directly above that point."
- El Camino Real. From Ninth Avenue south to the city limits, R3 lots fronting El Camino Real keep "A minimum of ten (10) feet along El Camino Real frontage, where property is developed with buildings over two stories in height," and "One-half (1/2) the height of any building, where the property is adjacent to residential districts."
- Combining yards. "At the City's option, required yards may be combined in various ways to maximize certain locational factors," decided during review of the planning application.
- Height limit. R3, R4 and R5 each point to "the Building Height Plan of the General Plan." Since April 2025 the heights in Table LU-1 of General Plan 2040 control; see the Measure T page.
- Features above the height limit. Section 27.02.060 exempts parapet walls, skylights, roof gardens and similar features "provided that they do not add floor area," and roof top mechanical equipment such as elevators and solar collectors if it is screened from the public right-of-way.
Downtown Districts
The downtown residential districts use fixed yards. R4-D asks for a 20-foot front yard, 15-foot side yards, and a rear yard of 25 feet or 25 percent of the parcel depth, "whichever is greater, up to a maximum of forty (40) feet." R5-D asks for 15-foot side yards and a 25-foot rear yard, and R6-D for 20 feet at the front, 15 at the sides and 25 at the rear. Parcel coverage is limited to 45 percent in R4-D and 55 percent in R6-D.
Chapter 27.40 adds a bulk rule inside the Downtown Specific Plan area. Up to 55 feet there is "No limitation" on the size of a floor. From 56 to 75 feet the part of the building above 55 feet is limited to a "maximum building dimension of 150 lineal feet and maximum diagonal dimension of 170 lineal feet." In the CBD district, new buildings "shall be built to the property line to a minimum height of 26 feet."
Parking
| Use | Minimum parking spaces |
|---|---|
| House under 3,000 sq ft of floor area | 2 garage spaces |
| House of 3,000 to 3,749 sq ft | 2 garage spaces plus 1 more space, which may be uncovered |
| House of 3,750 sq ft and above | The spaces above plus 1 for each 750 sq ft of floor area |
| Multiple-family home, studio | 1.5 (1.3 resident and 0.2 visitor) |
| Multiple-family home, one bedroom | 1.8 (1.6 resident and 0.2 visitor) |
| Multiple-family home, two bedrooms | 2.0 (1.8 resident and 0.2 visitor) |
| Multiple-family home, three or more bedrooms, or over 1,400 sq ft | 2.2 (2.0 resident and 0.2 visitor) |
| Downtown Retail Core, studio to three or more bedrooms | 1.2, 1.5, 1.7 and 2.0 per home |
| ADU or junior ADU (Chapter 27.19) | None |
| SB 9 unit (Chapter 27.21) | 1 per unit, with transit and car share exemptions |
Source: San Mateo Zoning Code, 27.18.110, 27.64.100, 27.64.160, 27.19.060 and 27.21.070. House floor area excludes enclosed parking, uninhabitable accessory structures and covered patios.
- Who the apartment row covers. The multiple-family row names "two-family, townhouse, condominium, apartments and apartment hotels," and "Resident parking shall include at least 1 covered stall per dwelling unit."
- Rounding. "When determination of the number of off-street parking spaces required by this title results in a requirement of a fractional space, an additional space shall be provided." By VanPlex arithmetic, four two-bedroom homes need 8 spaces, and three one-bedroom homes need 5.4, which becomes 6.
- Adding homes to an existing building. New homes need their full parking, and "Each existing unit that does not comply with this chapter shall be provided with at least one (1) garage space."
- Bedrooms. "Each room meeting the standard of The Building Code as a bedroom, shall be counted as a bedroom in determining parking requirements."
- Compact stalls. Where 10 to 100 spaces are required, 30 percent may be compact, and 40 percent where more than 100 are required.
- Bicycles. Outside downtown, multiple-family homes need 1.0 long-term bicycle space for a studio or one-bedroom home, 1.25 for two bedrooms and 1.5 for three or more, plus 0.05 to 0.15 short-term spaces per home.
- Leases. Homes must be offered with their parking: "All residential dwelling units shall be provided with the existing or required amount of off-street parking as a part of the sales, lease or rent agreement for the dwelling unit."
Downtown has its own system. Inside the Central Parking and Improvement District, a new project may fund a parking demand study or meet the table in Section 27.64.100, and a project outside the Limited Parking Zone "must satisfy a minimum of 25% of the project's required parking through provision of on-site parking." In the CBD district, "Parking requirements for residential uses may be satisfied by a contract with the CPID or payment of in-lieu fees, provided at least one (1) parking space per unit is provided on-site." An in-lieu fee is paid in place of building the spaces. The Development Fees summary lists it at $61,661.54 per space. In the Hillsdale Station Area and the TOD district, the parking numbers come from the area plans, which this guide did not read.
State law may remove these minimums near the train stations. Government Code 65863.2 says "A public agency shall not impose or enforce any minimum automobile parking requirement on a residential, commercial, or other development project if the project is located within one-half mile of public transit," and defines public transit as "a major transit stop." A city may keep a minimum by making written findings, but that exception does not apply to a housing project that "contains fewer than 20 housing units." The statute covers charter cities by name. Chapter 27.64 does not mention it; ask the Planning Division how it applies the statute to a site.
Variances
A variance is permission to depart from a measured standard because of conditions on the lot. Chapter 27.78 requires four conditions, the first being "exceptional or extraordinary circumstances or conditions applicable to the property that do not apply generally to property in the same zone or neighborhood." Section 27.78.040 lists what may be varied: yards, build-to lines (lines a wall must be built up to), floor area ratio, the use of a lot that is too small in area, and the number or size of parking spaces. It adds that "there shall be no increase in the number of units permitted on a site." The Zoning Administrator decides variances "for single-family, accessory dwelling units, duplex dwellings, or residential projects with up to six (6) residential dwelling units," and the Planning Commission decides the rest.
Where the Texts Differ
- ADU parking. The parking table still lists one space for an ADU, and its bicycle table still names a "Secondary Unit." Chapter 27.19, amended in February 2026, requires no ADU parking. See the ADUs and SB 9 page.
- R1 parking in two places. The house parking table is printed in both Section 27.18.110 and Section 27.64.160. The two copies match.
- Building height. The definition of building height measures to the plate line. The R1 section adds a second limit to "the highest point of the roof." The proposed R6 to MU4 districts state heights in stories and feet with no measuring rule of their own.
- Parking near transit. Chapter 27.64 sets minimums citywide, and Government Code 65863.2 bars minimums within one-half mile of a major transit stop. The statute controls where it applies.
Limits of This Page
The code was read from the City's bulk copy, whose index page prints "Current through" October 8, 2026. Diagrams in Chapter 27.18 are images and were not read. The R1 Single Family Dwelling Design Guidelines, the objective design standards, the City's Standard Drawings and Specifications for stall sizes, the Downtown Specific Plan, the Rail Corridor Plan and the Hillsdale Station Area Plan were not read. Fence, landscape and tree rules (Chapters 27.71, 27.84 and 13.40) are left out. Ask the Planning Division which standards apply to your lot.
Best For
- ✓ R1-B and R1-C lots, where a 15-foot front yard and 5-foot side yards leave the widest building area.
- ✓ Two-story houses designed under the 12-foot, 45-degree daylight plane from the first sketch.
- ✓ Apartment sites within one-half mile of a major transit stop, where state law limits parking minimums.
Usually Fails When
- ✕ A second story is drawn 15 feet from the rear line, where new construction above a single story needs 25 feet.
- ✕ An R3 building of three stories is placed 6 feet from the side line, where one-half the height applies.
- ✕ A parking count is rounded down, when the code adds a space for any fraction.
What To Verify Before Spending Money
- → Floor area already on the lot, including garages, sheds and covered patios, against the R1 ratio.
- → Whether the lot abuts an R1 or R2 parcel, which raises the yards of an apartment building.
- → Whether Government Code 65863.2 removes the parking minimum on the site.
Where to Go Next
Related on VanPlex: the San Mateo overview, the three or more homes page and the California ADU law page.
Frequently Asked Questions
What are the setbacks for a house in San Mateo, California?
How tall can a house be in San Mateo?
What is the daylight plane in San Mateo?
What is the floor area ratio for a house in San Mateo?
How many parking spaces does a house need in San Mateo?
How much parking does an apartment building need in San Mateo?
Does state law remove parking minimums near Caltrain in San Mateo?
What are the setbacks for an apartment building in San Mateo?
How does San Mateo measure building height?
Can I get a variance from a setback or parking rule in San Mateo?
Official sources (checked October 2026)
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