South San Francisco, CA

South San Francisco regulates noise under SSFMC Chapter 8.32 (Noise Regulations). The ordinance prohibits loud, unnecessary noise disturbing neighborhood peace. Quiet hours for residential zones are generally 10 PM to 8 AM.

South San Francisco prohibits nuisance barking under the general noise ordinance (SSFMC Ch. 8.32). Animal control in SSF is provided by Peninsula Humane Society & SPCA. Habitual barking disturbing neighbors is a code violation.

South San Francisco permits construction with a valid city permit weekdays 8 AM–8 PM, Saturdays 9 AM–8 PM, and Sundays/holidays 10 AM–6 PM. Equipment noise cannot exceed 90 dB at 25 feet. SSFMC §8.32.

Unincorporated San Mateo County has no dedicated gas-powered leaf blower ban or specific leaf-blower ordinance; the recent leaf-blower bans and electric-blower rebate programs are city-level (e.g., City of San Mateo, Atherton, Redwood City). In unincorporated areas, blowers are governed by the general Chapter 4.88 noise standards.

Amplified music in unincorporated San Mateo County is regulated by County Code Chapter 4.88: it must stay within the exterior dBA limits of Section 4.88.330 and must not be unreasonably loud under the General Noise Regulation (4.88.350). There is no separate county amplified-sound permit chapter in the noise code itself.

Noise from motor vehicles operated on public roads in unincorporated San Mateo County is primarily controlled by the California Vehicle Code, which requires an adequate muffler and prohibits modified exhaust that amplifies noise. The County's Chapter 4.88 noise limits generally address stationary, on-property noise rather than vehicles in transit on public rights-of-way.

County Code 4.88.330 sets exterior noise limits at residences, schools, hospitals, churches and libraries on a sliding scale by how long the noise lasts in an hour. Daytime (7 a.m.-10 p.m.) limits run from 55 dBA (30 min/hr) up to 75 dBA (instantaneous max); nighttime (10 p.m.-7 a.m.) limits are 5 dBA lower, from 50 to 70 dBA.

Outdoor music in unincorporated San Mateo County must comply with the exterior decibel limits in County Code 4.88.330 and must not be unreasonably loud under 4.88.350. The County noise code has no special outdoor-music exemption, so evening and late-night events face the stricter 10 p.m.-7 a.m. nighttime limits.

Industrial and commercial noise in unincorporated San Mateo County is controlled through the exterior noise standards of County Code 4.88.330 (measured at nearby residences, schools, hospitals, churches and libraries) and the General Noise Regulation 4.88.350, with construction-noise exemptions limited to set hours under 4.88.360.

Aircraft noise is regulated by the FAA under federal law, not by the County's local noise ordinance. The County of San Mateo operates San Carlos and Half Moon Bay airports and runs a voluntary Airports Noise Abatement Program with voluntary flight procedures, a 'Fly Friendly' education effort and a noise-complaint hotline at (844) 266-6266.

South San Francisco restricts large commercial vehicles from parking in residential zones. South San Francisco's industrial character means commercial vehicles are common, but residential streets remain regulated.

South San Francisco enforces CVC 72-hour abandonment rule, street sweeping restrictions, and residential time-limit zones. The city is densely developed (biotech/industrial hub) with significant parking demand in residential areas.

South San Francisco requires vehicles to be parked on legal paved parking areas. Blocking public sidewalks is prohibited. Garage conversion ADUs do not require replacement parking under California state law.

South San Francisco restricts RVs and oversized vehicles from long-term parking on residential streets. CVC 72-hour rule applies. Private property storage is generally allowed subject to zoning and HOA restrictions.

Unincorporated San Mateo County has no blanket overnight on-street parking ban. The County Ordinance Code instead targets oversized vehicles and trailers on designated streets (Section 7.28.070) and limits commercial vehicles in residential zones to one hour (Section 7.28.030). Otherwise, the state 72-hour rule and any posted local time limits control overnight parking.

County Ordinance Code Section 7.28.070 ("No Oversized Vehicle Parking") lets the Board of Supervisors bar oversized vehicles over six feet high from designated residential streets and trailers of any size from designated public streets in the unincorporated area. Exceptions cover loading, public-utility service, up to eight hours for emergency repairs or a tow, emergency vehicles, and wheelchair-accessible vans.

For new construction in unincorporated San Mateo County, the County's local amendments to the California Building and Energy Codes require EV charging infrastructure. Adopted February 25, 2020 and effective for permits, the rules require commercial buildings (excluding office) to install Level 2 EV charging at 6% of parking spaces and Level 1 circuits at 5%. Residents apply for EV charger permits through County Planning and Building.

On unincorporated County streets, yellow curbs are freight loading zones for active loading and unloading only (not for parking commercial-plated vehicles), and white curbs are passenger loading zones. On private development sites, the Title 8 Development Code requires off-street loading spaces sized at least 10 feet by 25 feet with 15 feet of vertical clearance for uses that receive or distribute merchandise.

Curb markings on unincorporated County roads are installed by the Department of Public Works and only after Board of Supervisors approval. Standard California curb colors apply: red means no parking, green means time-limited parking, yellow and white are loading zones, and blue is disabled parking. The County charges $80 plus $10 per foot for paint and/or signs; residents may not paint County curbs themselves.

Under County Ordinance Code Chapter 7.60, it is unlawful and an infraction to abandon, park, store, or leave any abandoned, wrecked, dismantled, or inoperative vehicle on public or private property for more than ten days unless fully enclosed in a building. The County adopts this abatement authority under California Vehicle Code Section 22660, and Section 7.60.140 makes violation an infraction.

South San Francisco requires property owners to maintain lots free of excessive weeds and overgrown vegetation. Overgrowth creating fire hazards or nuisances is subject to code enforcement and potential city abatement.

South San Francisco water is supplied by Cal Water (South San Francisco District) primarily from SFPUC's Hetch Hetchy system. BAWSCA and state drought regulations may limit outdoor watering. Water waste is prohibited year-round.

Private tree removal on private property in South San Francisco generally does not require a city permit. Street tree removal requires Public Works approval. Trees in special overlay zones may need additional review.

Private tree trimming in South San Francisco does not require a city permit. Street trees (public right-of-way) require Public Works approval. Trees near PG&E lines must be managed per utility clearance standards.

Unincorporated San Mateo County abates hazardous fire vegetation through its fire districts under California Health & Safety Code 14875 et seq. and Government Code 25845. Programs such as Coastside Fire's require mowing weeds and grass to no taller than 4 inches; lots of one acre or less are cleared entirely, and larger lots need a 30-foot perimeter fire break.

Residential rainwater harvesting is encouraged in unincorporated San Mateo County. Under California's Rainwater Capture Act, rooftop rain barrels and cisterns under 360 gallons for outdoor non-potable use need no state water permit. The Countywide Water Pollution Prevention Program offers rebates of $50-$150 per rain barrel, plus a possible $50 bonus in some areas.

Unincorporated San Mateo County encourages native and drought-tolerant landscaping rather than mandating it for homeowners. The Countywide Water Pollution Prevention Program promotes natives for pollinators and watershed health, and BAWSCA's Lawn Be Gone rebate pays up to $4 per square foot to replace lawn with low-water plants. WELO indirectly favors natives through plant-factor rules.

California's SB 1383 organics law requires unincorporated San Mateo County residents to keep food scraps, yard trimmings, and food-soiled paper out of the trash. Single-family homes get curbside organics (green cart) service and must sort organics into it. The County aims to cut organic-waste disposal 75% by 2025; non-compliance can lead to fines.

Unincorporated San Mateo County does not ban or specifically permit-regulate artificial turf on private property, and the County's WELO governs water budgets without mandating or prohibiting synthetic turf. A right-of-way permit is needed only if turf extends into the public parkway. California law (Civil Code 4735) bars HOAs from prohibiting water-efficient landscaping.

South San Francisco Municipal Code Section 20.350.037 and the Planning Division's Short-Term Rental program do not specify a dollar-amount liability insurance requirement for STR hosts. The City's published STR program materials reference permit, business license, TOT/CCT, parking, and local-contact obligations but do not impose a numeric minimum general-liability or umbrella policy. Hosts using major platforms typically receive platform-provided host protection (Airbnb's AirCover offers up to $1,000,000 in liability coverage; Vrbo's Liability Insurance offers up to $1,000,000 per occurrence) but this is not a city mandate. Hosts should confirm their homeowner's or renter's policy permits STR use and consider a dedicated short-term rental policy.

South San Francisco Municipal Code Section 20.350.037 caps short-term vacation rental occupancy by stay type. Hosted stays (host present in the dwelling) are limited to a maximum of 2 guests at one time. Un-hosted stays (host absent) are limited to 2 guests per bedroom plus 2 additional guests per booking. STR use is restricted to single-unit dwellings only — multi-family units, accessory dwelling units (ADUs), and junior accessory dwelling units (JADUs) may not be used as short-term rentals. Un-hosted stays are further capped at 90 days per year, while hosted stays have no annual day limit. Only one STR permit is allowed per dwelling unit per lot.

South San Francisco requires STR properties to provide at least one designated off-street parking space. Guests must comply with all city parking rules. Oversized vehicles and unattached trailers are restricted in residential areas.

STR guests in South San Francisco must comply with SSFMC Ch. 8.32 noise regulations. Hosts are responsible for guest conduct. The local contact must be reachable within 1 hour to address disturbances.

South San Francisco charges TOT under SSFMC Ch. 4.20 starting at 11% general + 1% special, automatically increasing 1%/year up to a 14% maximum. A Conference Center Tax (CCT) also applies. Business license also required.

South San Francisco requires a Short-Term Rental Permit under SSFMC §20.350.036. STRs allowed only in single-family homes by permanent residents. ADUs ineligible. Unhosted stays capped at 90 days/year. Business license required.

Registration is handled through a Short-Term Rental Permit application to the Planning and Building Department plus a Transient Occupancy Registration Certificate from the Tax Collector. Owners must designate a local contact, post performance standards, and meet fire-safety standards before a permit issues.

San Mateo County's Coastal Zone STR ordinance does not require the rental to be the owner's primary residence. Non-owner-occupied (whole-home) short-term rentals are allowed, subject to the permit, a 180-night cap, and all performance standards under Section 6401.3.

Owner presence is not required, but Section 6401.3(6)(c) requires a designated local contact person within a 20-mile radius, available at all times during occupancy, able to physically respond within one hour in emergencies. Owner-present nights are exempt from the 180-night cap.

Under Section 6401.3(2)(c), a Coastal Zone STR cannot be rented for more than 180 nights per calendar year. Any night the property owner is present at the address does not count against the 180-night limit.

South San Francisco Municipal Code Chapter 20.300 (Lot and Development Standards) and Chapter 20.330 (On-Site Parking and Loading) govern carports as accessory structures. Unlike many neighboring cities, SSFMC Section 20.330.004 expressly allows the required residential parking space to be 'within a carport or garage' — open carports are an acceptable form of required parking. Carports must comply with a minimum 5-foot setback for accessory structures, must be at least 6 feet from the main building, and accessory-building height is limited to an average of 12 feet between floor slab and ridge pole. Combined accessory-building footprint may not exceed 20 percent of the main building's footprint or 220 square feet, whichever is greater. A building permit is required.

South San Francisco allows ADUs per California state law (SSFMC Title 20). Detached ADUs up to 1,200 sq ft max; minimum 800 sq ft and 16 ft allowed by right. 4-ft setbacks. ADUs cannot be STRs.

Small accessory structures (sheds) in South San Francisco must comply with SSFMC Title 20 setbacks. Sheds under 120 sq ft and under 8 feet generally do not require a building permit but must still meet zoning requirements.

Garage conversions to ADUs are permitted in South San Francisco per California ADU law. Building permit required. No replacement parking needed when converting a garage to an ADU under state law.

Unincorporated San Mateo County has no separate tiny-home ordinance. A tiny home on a permanent foundation can qualify as an ADU under Development Code Chapter 8.392. California ADU law requires a permanent foundation, so movable tiny homes on wheels generally do not qualify as ADUs.

Open burning is banned in South San Francisco under BAAQMD Regulation 5. Wood-burning devices (fireplaces, stoves, fire pits) are prohibited on Spare the Air Alert days under BAAQMD Regulation 6, Rule 3.

All fireworks are illegal in South San Francisco — including 'Safe and Sane' fireworks. The Police Chief has confirmed that even safe and sane fireworks result in fines. San Mateo County fines are $1,000 per violation.

Wood-burning fire pits are prohibited on Spare the Air Alert days throughout South San Francisco under BAAQMD Regulation 6, Rule 3. With 19–41 annual alert days, outdoor wood burning is severely limited.

Properties in the Wildland-Urban Interface of unincorporated San Mateo County must maintain defensible space under California Public Resources Code 4291: 100 feet of clearance around structures. CAL FIRE / San Mateo County Fire conducts defensible space inspections, and roadside vegetation must be cleared to specified clearances.

Small recreational backyard fires are allowed in unincorporated San Mateo County under California Fire Code section 307.4 with required setbacks and constant attendance, but all backyard burning of yard waste or trash is prohibited and wood fires are banned on Spare the Air days under BAAQMD Regulation 6, Rule 3.

Smoke alarms in unincorporated San Mateo County dwellings are governed by California Health & Safety Code section 13113.7 and the California Fire/Building Codes. Newer battery-only alarms must have a 10-year sealed non-replaceable battery, and alarms must be replaced 10 years after the manufacture date. Violations are a $200 infraction.

Propane (LPG) storage in unincorporated San Mateo County follows the California Fire Code Chapter 61 and NFPA 58, enforced by CAL FIRE / San Mateo County Fire. Residential aggregate capacity is limited, tanks must meet setback and clearance rules, and permits are required above threshold quantities.

Unincorporated San Mateo County contains Moderate, High, and Very High Fire Hazard Severity Zones, with the Santa Cruz Mountains and coastal hills (La Honda, Pescadero, and similar) at the highest risk. Mapped zones trigger defensible space (PRC 4291), WUI building standards (CBC Chapter 7A), and real estate disclosure.

South San Francisco fence heights are governed by SSFMC Title 20 (Zoning Code). Standard residential limits are 3–4 ft in front yards and up to 6 ft in side/rear yards. The updated zoning code addresses measurement methodology.

Standard residential fences within height limits in South San Francisco generally do not require a building permit. Fences over 6 feet, masonry fences, or fences requiring footings may need a permit. Contact Building Division.

Fence cost sharing between neighbors in South San Francisco is governed by California Civil Code §841 (Good Neighbor Fence Act). Written notice of 30 days is required before constructing a shared fence.

A building permit is required for a fence built on top of a retaining wall in unincorporated San Mateo County. Under the California Building Code, retaining walls over 4 feet high (measured from the bottom of the footing) — or any wall supporting a surcharge — also require a permit.

Fences in unincorporated San Mateo County must comply with Chapter 8.332 height limits, corner-lot sight-distance rules, and grade-based measurement. Pool fencing, right-of-way encroachment, and Coastal Zone parcels carry additional requirements.

San Mateo County's countywide fence ordinance (Ch. 8.332) regulates fence height and placement rather than materials, and expressly recognizes wood and cyclone fencing. Some specific districts and design-review overlays restrict materials like chain link, corrugated metal, and masonry near street frontages.

Wood and cyclone (chain-link) fences are the standard, permit-exempt materials in unincorporated San Mateo County when built within height limits. Masonry fences require a building permit, and certain districts restrict materials near street frontages.

Unincorporated San Mateo County enforces California Swimming Pool Safety Act (H&S Code §115920-115929) and CBC Chapter 31B. Minimum 60-inch barrier, self-closing/self-latching gates, plus at least TWO additional drowning prevention features for new pools since 2018.

South San Francisco requires dogs to be leashed on public property. No voice-control exemption exists in San Mateo County. Animal control is provided by Peninsula Humane Society & SPCA at (650) 340-8200.

South San Francisco does not have a breed-specific ban. All dogs must be licensed with San Mateo County. Dogs deemed dangerous after an incident may face enhanced restrictions including containment and liability insurance requirements.

South San Francisco does not have a specific beekeeping ordinance. Beekeeping in residential zones may be subject to nuisance provisions. Contact the Planning Division before installing hives.

South San Francisco follows California CDFW regulations banning many exotic species. Local animal code may restrict wild or dangerous animals. Contact Peninsula Humane Society & SPCA for guidance.

Unincorporated San Mateo County allows backyard chickens and ducks on residential parcels of at least 2,500 square feet. Up to 6 birds are allowed on lots of 2,500 to 7,499 square feet and up to 10 on lots of 7,500 square feet or more. Roosters are prohibited, and birds must be kept in a rear-yard coop.

In unincorporated San Mateo County, a household keeping more dogs or cats needs a permit. An animal fanciers permit covers up to a total of ten dogs and/or cats, and a kennel or cattery permit is required to keep more than ten dogs, cats, or any combination per dwelling or business.

Keeping livestock in unincorporated San Mateo County depends on the parcel's zoning district. Animal control under Title 6 covers dogs, cats, exotic animals, and poultry, while livestock such as horses, cattle, sheep, and goats is governed by the County zoning/Development Code, which permits agricultural animals on appropriately zoned and sized rural and agricultural parcels.

Cats over three months old in unincorporated San Mateo County must be licensed and rabies-vaccinated. The County Ordinance Code also requires that unaltered cats over six months be either spayed/neutered or covered by an unaltered-animal license or breeding permit. There is no general cat-leash requirement.

The County Ordinance Code does not contain a specific prohibition on feeding wildlife in unincorporated San Mateo County. County agencies strongly advise against feeding deer, coyotes, raccoons, and other wild animals because it draws predators and creates nuisances. Intentionally interfering with certain wildlife is also restricted by California state law.

Unincorporated San Mateo County has no separate 'hoarding' ordinance, but its permit tiers cap how many animals a household may keep and its animal-care standard prohibits neglect. Keeping animals without proper food, water, shelter, or care violates the County Code, and severe neglect is a crime under California Penal Code Section 597.

Above-ground pools over 18 inches in depth in South San Francisco require a building permit and must meet California pool safety fencing requirements. Temporary inflatable pools under 18 inches are generally exempt.

New pools in South San Francisco require a building permit. All pools must comply with California Swimming Pool Safety Act. Pool equipment noise must meet Ch. 8.32 standards (per the updated zoning code). Anti-entrapment drains required.

Pool fences in South San Francisco must comply with California H&S §115920: minimum 60-inch barrier, self-closing/self-latching gates, ground clearance under 2 inches, no gaps over 4 inches. Two drowning prevention features required.

Spas and hot tubs in unincorporated San Mateo County require a County pool/spa building permit and are subject to California's Swimming Pool Safety Act. A spa equipped with an approved safety cover (ASTM F1346) can satisfy the barrier requirement that otherwise applies to pools.

In unincorporated San Mateo County, building a swimming pool or spa requires a building permit and a boundary survey from the Planning and Building Department. Applicants submit plot plans, structural/plumbing/electrical and mechanical details, engineering and energy calculations, and pay building, plan-check and related fees.

Home-based businesses in South San Francisco require a Home Occupation Permit under SSFMC Title 20. The business must be incidental to the residential use with no exterior evidence or non-resident employees.

No exterior business signage is permitted for home-based businesses in South San Francisco residential zones. Any commercial identification visible from the street violates Home Occupation Permit conditions.

Customer visits to home businesses in South San Francisco are restricted to incidental levels consistent with residential uses. Retail sales, regular appointments creating parking demand, and commercial deliveries are prohibited.

Unincorporated San Mateo County does not require a separate home-occupation permit. A customary, incidental home occupation is allowed by right in residential zones as long as all the County's home-occupation conditions are met, so no special application or land-use approval is needed.

Cottage food operations in unincorporated San Mateo County are regulated under California's Homemade Food Act. San Mateo County Environmental Health registers Class A operations and permits/inspects Class B operations. Class A is capped at $75,000 and Class B at $150,000 in annual gross sales, and operators are limited to a set product list.

By California state law (Health & Safety Code 1597.40-1597.46, as amended by SB 234), small and large family day care homes are a residential use by right in unincorporated San Mateo County. No conditional use permit is required, and the County cannot impose a business license, fee, or tax to operate one. The home must be licensed by the State.

Parts of South San Francisco near the Bay shoreline and low-lying industrial areas are in FEMA flood zones. New construction in Special Flood Hazard Areas requires elevation and a floodplain development permit. Sea level rise is a key risk.

San Mateo County Planning & Building Department requires submittal of an Erosion and Sediment Control Plan prior to issuance of any demolition, grading, or building permit that involves site disturbance. Standard BMPs include silt fencing, straw wattles, erosion control blankets, stabilized construction entrances, and covered stockpiles. Wet-season work (October 1 - April 30) triggers additional inspection requirements and may be restricted on steep slopes. SWPPP required for sites 1+ acre.

Unincorporated San Mateo County is a permittee under the San Francisco Bay Area Municipal Regional Stormwater Permit (MRP 3.0, Order R2-2022-0018) which imposes NPDES Phase I stormwater requirements. Projects creating/replacing 2,500+ sq ft of impervious surface trigger C.3 post-construction stormwater treatment requirements (LID, biofiltration). Illicit discharges to storm drains are prohibited. Construction sites disturbing 1+ acres require SWPPPs and monthly wet-season inspections.

San Mateo County administers its own certified Local Coastal Program (LCP) and issues Coastal Development Permits (CDPs) for projects in the Coastal Zone, which covers roughly 240 sq miles from Devil's Slide south through Pescadero, Año Nuevo, and the Santa Cruz County line. Projects in the Coastal Zone typically require a CDP from County Planning; certain appealable areas (near the shoreline, in sensitive habitat, or in rural areas) can also be appealed to the California Coastal Commission. ESHA (Environmentally Sensitive Habitat Area) buffers, public access, and view corridors are key LCP policies.

San Mateo County requires a Grading Permit from Planning & Building for projects involving more than 250 cubic yards of cut and/or fill, or any grading on slopes over 20%, or grading within 100 ft of a watercourse. Drainage design must direct runoff away from structures and must not adversely redirect water onto neighboring properties. Retaining walls over 4 feet in height need separate engineering and permits. Pre-site erosion-control and tree-protection inspection may be required.

Cannabis retail dispensaries are PROHIBITED in unincorporated San Mateo County. The Board of Supervisors has adopted a ban on all commercial cannabis retail licenses under MAUCRSA. Limited commercial cultivation (mixed-light greenhouse and nursery) is allowed only on parcels designated Agriculture in the General Plan with a County commercial cannabis license. Delivery from licensed operators in other jurisdictions into unincorporated areas is permitted per state law (Bus & Prof Code §26090) and cannot be banned locally.

Unincorporated San Mateo County allows adults 21+ to cultivate up to 6 cannabis plants per residence for personal, non-medical use under County Code Chapter 5.148 (Personal Cultivation). Cultivation must occur inside a private residence or a fully enclosed and secure accessory structure — OUTDOOR personal cultivation is PROHIBITED in unincorporated San Mateo County, going further than state law's baseline. Qualified medical patients may also cultivate indoors. Sale or commercial distribution requires a commercial cannabis license, which the County does NOT issue for retail activities.

Unincorporated San Mateo County does not codify a specific numeric annual cap on garage sales per household, but treats sales as permissible incidental residential use when occasional — typically understood as 2-4 per year. Holding sales with greater frequency or for extended durations can trigger home-business zoning review, require a business license, and constitute an unpermitted retail use of residential property. HOA communities often impose stricter limits (commonly 1-2 per year).

Unincorporated San Mateo County garage sales must stay within reasonable daylight hours, typically 8 AM to 6 PM, and remain within the Chapter 4.88 Noise Control exterior limits at the property line. Friday-Sunday weekend sales are most common. All merchandise, tables, and signs must be removed from public view at the end of each sale day. Leaving items outside overnight can trigger property blight/nuisance enforcement.

Unincorporated San Mateo County does not require a permit for occasional residential garage/yard sales. Sales are treated as incidental residential activity, not commercial operations, so long as they remain occasional and comply with County Code frequency and sign rules. Merchandise must be personal property, not goods purchased for resale — the latter would require a business license and zoning clearance as a home business or retail operation.

The San Mateo County Protected Tree Ordinance (No. 4895) requires replacement planting when a Significant or Heritage Tree is removed under permit. Standard replacement ratios range from 1:1 to 3:1 depending on the DBH and species of the removed tree. Replacement trees must meet minimum size specifications (typically 15-gallon to 24-inch box), be from an approved native/adapted species list, and established for a 2-year maintenance period. When on-site replacement is infeasible, an in-lieu fee is paid to the County Tree Replacement Fund.

The unincorporated County's Protected Tree Ordinance (Chapter 8.400, Ordinance 4895, 2024) requires a Protected Tree Removal Permit before removing protected trees, with replacement planting and a 3-year maintenance period. Exemptions cover dead trees, true emergencies, and specific fire-risk species near structures. A separate Coastal Zone exemption for hazardous trees runs through July 1, 2026.

Under the 2024 Protected Tree Ordinance (No. 4895), San Mateo County designates Heritage Trees based on exceptional size, species rarity, historical significance, or ecological value. Heritage status can be conferred on mature coast live oaks, valley oaks, redwoods, and other native specimens. Removal is rarely permitted except for documented safety emergencies, and damage to a Heritage Tree triggers the most severe penalties under the ordinance, with fines up to $25,000 per tree plus restoration and restitution.

Residential building height limits in unincorporated San Mateo County are set by district. The Planned Agricultural District caps structures at 3 stories or 36 feet, with a 28-foot limit in the Midcoast area. Public and institutional buildings may reach 75 feet with increased yards.

In unincorporated San Mateo County, residential side yards are generally at least 5 feet and rear yards at least 20 feet, while the required front yard is set by the combining 'S' (site) district shown on the Zoning Maps. Setbacks vary significantly by district.

Lot coverage and floor-area limits in unincorporated San Mateo County are district-specific. Several residential districts cap building site coverage at 25 percent and floor-area ratio around 30 percent (or a minimum square-foot allowance), with stricter standards in some areas.

Unincorporated San Mateo County uses expedited solar permitting under California AB 2188 (Solar Rights Act). Residential rooftop systems under 10 kW qualify for same-day online permits through SolarAPP+ or the County Building Division. Fire setbacks per CFC Chapter 11B.

California Civil Code §714 (Solar Rights Act) strongly limits HOA authority to restrict solar panels. HOAs in unincorporated San Mateo County (Emerald Hills, West Menlo Park subdivisions) cannot effectively prohibit solar or impose costs over $1,000 or reduce efficiency over 10%.

Mobile food facilities operating in unincorporated San Mateo County must obtain a Mobile Food Facility (MFF) permit from San Mateo County Health Environmental Health Services (EHS), pay the annual permit fee, pass a pre-operational vehicle inspection, secure a commissary agreement with a permitted commercial kitchen, and hold a California Food Handler Card. MFF permits run February 1 through January 31 annually. Contact EHS at (650) 372-6200.

Unincorporated San Mateo County does not designate specific food truck vending zones but restricts operations through general zoning and parking rules. Food trucks may not vend from the public right-of-way for extended periods (not a permitted commercial use), must comply with parking time limits on County roads, and cannot operate within 500 feet of a school during school hours per Education Code §49535.5. Private property vending requires property owner written permission and may trigger a use permit.

San Mateo County Code Chapter 3.04 (Juvenile Curfew Regulations) prohibits minors under 18 from being in public places within unincorporated areas of the County between 11:30 PM and 5:00 AM on weeknights, and between 12:30 AM and 5:00 AM Friday, Saturday, and holiday nights. A daytime truancy curfew applies during school hours. Standard exceptions include minors accompanied by a parent/guardian, traveling to or from work or school activities, or in case of emergency.

San Mateo County parks open at 8:00 A.M. and close at a preset time prior to sunset. Under County Code Section 3.68.080, it is unlawful to remain in any County park or recreation area after the posted closing time without lawful business there.

Outdoor cooking with BBQ grills and propane is generally allowed at residences in unincorporated San Mateo County and is not restricted by the open-burning or Spare the Air wood rules. The California Fire Code regulates where open-flame and LP-gas grills may be used near combustibles and on multifamily balconies.

Backyard smokers and wood/charcoal BBQs are allowed at residences in unincorporated San Mateo County as cooking devices, not regulated open burning. But because smokers burn wood or charcoal, BAAQMD's Spare the Air guidance discourages their use on no-burn days, and the California Fire Code restricts solid-fuel cooking near combustibles and in high fire areas.

In unincorporated San Mateo County, the Planning and Building Code Compliance Section enforces property-maintenance standards and abates public nuisances such as accumulated refuse, junk, and deteriorated structures. When a nuisance is confirmed, the owner gets a Notice and Order to Abate with 10 days to correct; if ignored, the County abates and bills actual costs plus 15%.

Unincorporated San Mateo County does not publish a lawn-height number in its general code, but the County's Notice of Violation forms apply an International Property Maintenance Code standard requiring overgrown and dead weeds and vegetation to be removed and kept at 18 inches or less. Separately, fire-hazardous weeds are abated under California Health and Safety Code authority.

San Mateo County does not appear to publish a dedicated garage-sale ordinance for unincorporated areas, and no County permit requirement for occasional residential sales could be confirmed from a primary source. Sales are treated as an incidental residential activity, but must not create a public nuisance, block sidewalks or roadways, or violate sign and zoning rules enforced by Code Compliance.

Snow sidewalk clearing is not a regular concern in unincorporated San Mateo County's Mediterranean coastal climate, and the County has no dedicated snow-clearance ordinance. On the rare occasions of snow at Skyline Ridge or upper La Honda/Kings Mountain elevations, Caltrans clears State Routes 35, 84, and 92, while property owners are generally responsible for keeping their own driveways and sidewalks (where they exist) passable. Streets & Highways Code §§5610-5618 gives local agencies general authority over abutting-property sidewalk maintenance.

Unincorporated San Mateo County properties used for residential purposes within the Service Area receive a minimum curbside service set by County Code Section 4.04.220, which includes garbage, recycling, and organics carts collected weekly. The County pays the cost of the minimum service levels to the authorized hauler, and those service charges are collected along with the property tax.

There is no special vacant-lot ordinance unique to unincorporated San Mateo County; vacant parcels meet the same public-nuisance and property-maintenance standards Code Compliance enforces countywide. Accumulated refuse, junk, and overgrown or dead vegetation can be declared a nuisance and abated after a 10-day notice, with costs plus a 15% fee billed to the owner.

Recology San Mateo County residential customers receive two free curbside Bulky Item Collection appointments per calendar year, scheduled February 1 through December 31 on the regular collection day. Each appointment accepts a defined set — one large appliance, one bulky item, one e-waste item, and up to twelve 32-gallon bags — with weight and size limits and hazardous/construction exclusions.

In the unincorporated Service Area, County Code Chapter 4.04 establishes mandatory minimum residential collection — garbage, recycling, and organics carts picked up once a week. Recology San Mateo County serves franchised areas including County Service Area 8 (North Fair Oaks); other unincorporated pockets are served by GreenWaste, Republic Services, South San Francisco Scavenger, or Kunz Valley Trash under non-exclusive franchises.

Setout rules in unincorporated San Mateo County are set mainly by the franchised hauler. Recology instructs residents to place carts curbside before 6 a.m. on the service day, wheels against the curb and lid toward the street, spaced about 2 to 3 feet apart facing the same direction. County Code separately requires materials to be contained in transit.

Recycling is part of the mandatory minimum residential service under County Code Chapter 4.04, with single-stream recyclables collected weekly alongside garbage and organics. The County franchise color scheme is gray/black for garbage, blue for recycling, and green for compost. Electronics are banned from the trash, and businesses and multifamily properties must provide recycling containers under state law.

California SB 1383 requires residents and businesses to subscribe to and participate in organics (compost) collection. San Mateo County implements it for the unincorporated area by amending County Code Chapter 4.04, and standard residential service includes a weekly green organics cart for food scraps, food-soiled paper, and yard trimmings. The County conducts required annual compliance inspections.

Unincorporated San Mateo County's Development Code does not set a stand-alone political-sign chapter; temporary signs are addressed within district sign standards. Along state highways, California's Outdoor Advertising Act (B&P Code 5405.3) caps temporary political signs at 32 sq ft, placed no sooner than 90 days before an election and removed within 10 days after.

Unincorporated San Mateo County's Development Code has no separate garage-sale-sign ordinance; signs are addressed through district sign standards that prohibit off-premises and abandoned signs. Signs may not be placed in the public right-of-way, and temporary signs should be removed promptly after the sale.

Unincorporated San Mateo County permits residential holiday decorations without permits. Displays must comply with electrical code, not obstruct public rights-of-way, and respect noise ordinance quiet hours (10 PM to 7 AM). Coastal zone properties may have additional restrictions.

Unincorporated San Mateo County has no countywide dark-sky ordinance, but the Development Code's design standards require exterior lighting to be designed and located so that direct light and glare are confined to the site and directed away from neighbors, with low-level, downward-directed lighting encouraged.

Unincorporated San Mateo County's Development Code requires exterior and interior lighting to be designed and located so that direct rays and glare are confined to the premises. The performance standards state no direct or reflected glare shall be visible, though reasonable shielded security lighting is allowed.

Many San Mateo County cities (Redwood City, San Carlos, others) maintain 'Do Not Knock' registries that residents can join free of charge, and the County Sheriff requires all licensed solicitors to check the registry and respect posted No Soliciting signs before knocking. Unincorporated areas rely primarily on posted signs — a sign reading 'No Soliciting' or 'No Trespassing' on a home, gate, or driveway is legally sufficient to make subsequent solicitation a citable offense under Penal Code §602 and County Code.

Unincorporated San Mateo County requires commercial peddlers and solicitors to obtain a Peddler/Solicitor License from the San Mateo County Sheriff's Office, including a fingerprint-based background check and photo ID badge. Licensed solicitors may operate 9 AM to sunset (or 8 PM, whichever is earlier), must display the County-issued badge visibly, and may not solicit at any address with a posted 'No Soliciting' sign. Religious, political, and charitable canvassing are exempt under First Amendment protections.

Unincorporated San Mateo County applies California's statewide just-cause eviction protections under AB 1482 (Civil Code §1946.2). After 12 months of tenancy, landlords must state an at-fault or no-fault reason. No-fault evictions require one month's rent in relocation assistance.

Unincorporated San Mateo County has NO local rent control. State law AB 1482 (Tenant Protection Act, Civil Code §1946.2 and §1947.12) caps annual rent increases at 5% plus CPI (maximum 10%) for qualifying units. Single-family homes owned by non-corporate owners and buildings under 15 years old are exempt.

Unincorporated San Mateo County does NOT have a rental registration program. Landlords must comply with state habitability laws (Civil Code §1941.1) and the California Building Code. Business license required only for property management companies, not individual landlords.

California evictions run through the unlawful detainer process. Under Code of Civil Procedure § 1161, nonpayment requires a 3-day notice to pay rent or quit (excluding weekends and holidays), and lease violations require a 3-day notice to cure or quit. No-fault terminations of covered tenancies require 30, 60, or 90 days. Self-help lockouts are illegal.

California landlords must keep rentals fit to live in. Civil Code §§ 1941 and 1941.1, reinforced by Green v. Superior Court, imply a warranty of habitability covering plumbing, heat, water, electricity, and sanitation. If repairs fail after notice, a tenant may repair and deduct up to one month's rent under § 1942 or withhold rent.

California Civil Code § 1954 limits when a landlord may enter a rented home. Except in emergencies, abandonment, or with tenant consent, the landlord must give reasonable written notice (24 hours is presumed reasonable) and may enter only during normal business hours, for specific permitted reasons such as repairs, inspections, or showings.

California sets no fixed dollar or percentage cap on rent late fees, but a late fee in a residential lease is treated as liquidated damages. Under Civil Code § 1671, such a fee is valid only if it reasonably estimates the landlord's actual loss from late payment; arbitrary penalty fees are unenforceable.

To end a California month-to-month tenancy, a tenant gives 30 days' written notice. A landlord gives 30 days if the tenant has lived there under a year, or 60 days if a year or more, under Civ. Code § 1946.1. AB 1482 requires just cause after 12 months; military and DV tenants may exit early.

California requires written notice before raising a month-to-month tenant's rent. Under Civ. Code § 827, increases of 10% or less in 12 months need 30 days' notice; increases above 10% need 90 days' notice. AB 1482 separately caps yearly increases on covered units.

As of July 1, 2024, California landlords may collect no more than one month's rent as a security deposit, regardless of whether the unit is furnished. The deposit, minus any lawful deductions, must be returned with an itemized statement within 21 days after move-out, or the landlord risks penalties of up to twice the deposit.

California adverse possession requires five years of continuous, open, hostile possession AND payment of all property taxes during that period under Code of Civil Procedure § 325. A squatter or trespasser who has not paid taxes gains no ownership and can be removed by unlawful detainer, ejectment, or a police trespass action.

Commercial drone operations in unincorporated San Mateo County require an FAA Part 107 Remote Pilot Certificate (14 CFR Part 107), LAANC authorization for controlled airspace (most of the Peninsula falls within SFO Class B), and coordination with affected airports (SQL, HAF, PAO, SFO). San Mateo County Parks prohibit commercial drone use; filming permits may be obtainable for specific projects via County Film Commission coordination. Commercial filming in the Coastal Zone may require a Coastal Development Permit.

Recreational drone flight in unincorporated San Mateo County is governed by FAA rules (49 USC §44809, 14 CFR Part 107 exemption) plus a countywide Park Orders ban: drones are PROHIBITED in all San Mateo County Parks (Huddart, Wunderlich, San Bruno Mountain, Edgewood, Pescadero Creek, Memorial, Sam McDonald, Junipero Serra, Crystal Springs). FAA Part 107 registration required for any drone over 0.55 lbs. SFO, Half Moon Bay Airport, San Carlos Airport, and Hayward Executive are nearby controlled airspaces requiring LAANC authorization.

California sets a statewide minimum wage floor under Labor Code 1182.12, currently $16.50 per hour for all employers as of 2025. Local governments are not preempted and may set higher minimums; many cities exceed the state rate substantially.

California's Healthy Workplaces, Healthy Families Act under Labor Code 245-249 mandates paid sick leave for nearly all employees statewide. SB 616 (2023) raised the minimum to 40 hours or five days annually effective January 2024, applying universally.

California regulates concealed carry weapons licenses statewide under Penal Code 26150 through 26225. Senate Bill 2 (2023) imposes uniform sensitive-place restrictions and applicant standards, preempting local variations on issuance criteria and qualifications.

California preempts most local firearm regulation under Government Code 53071 and Penal Code 25605, reserving licensing, registration, and manufacture authority to the state. However, local governments retain limited authority over discharge, sensitive places, and zoning of gun businesses.

California broadly prohibits open carry of firearms statewide under Penal Code 25850 (loaded firearms in public) and Penal Code 26350 (open carry of unloaded handguns). The prohibition applies uniformly across all California cities and counties without local variation.

California prohibits carrying loaded firearms in vehicles statewide under Penal Code 25400 and 25850. Unloaded handguns transported in private vehicles must be in a locked container or the vehicle's locked trunk; long guns must be unloaded but need not be locked.

California HOAs may levy regular and special assessments, charge late fees and interest, record liens, and ultimately foreclose on delinquent owners under the Davis-Stirling Act. State law (Civil Code sections 5650-5740) caps fees and interest and imposes strict notice steps and a delinquency threshold before any foreclosure may proceed.

California tightly regulates HOA governance. The Common Interest Development Open Meeting Act (Civil Code 4900-4955) governs board meetings and member access, sections 5100-5145 mandate secret-ballot elections with independent inspectors, and sections 5200-5240 give members broad rights to inspect association records.

California HOAs enforce recorded CC&Rs and architectural rules, but Civil Code section 4765 requires architectural decisions to be fair, reasonable, and in good faith, and sections 5900-5965 require internal dispute resolution plus an attempt at alternative dispute resolution before most enforcement lawsuits can be filed.

California HOAs may fine members for rule violations, but only under a published schedule of fines and after strict due-process steps. Civil Code section 5855 requires written notice and a hearing before any monetary penalty, and section 5725 bars fines from becoming a foreclosable lien on the home.

California overrides HOA governing documents on several owner protections. The Davis-Stirling Act and related Civil Code sections bar HOAs from prohibiting solar systems, U.S. flag displays, drought-tolerant landscaping, EV charging stations, and most noncommercial signs, even where local city rules are silent.

California prohibits state and local governments from requiring private employers to use the federal E-Verify system except where federal law mandates it, under Government Code 7285.1 and 7285.3. The restriction applies uniformly to every California city and county.

The California Values Act (SB 54, 2017) codified at Government Code 7284-7284.12 limits state and local law enforcement cooperation with federal immigration authorities. It applies uniformly to every California agency and bars participation in most civil immigration enforcement.

The California Land Conservation Act of 1965 (Williamson Act), Government Code 51200-51297.4, allows landowners to enter contracts with counties restricting land to agricultural use for ten-year minimum terms in exchange for reduced property tax assessment based on farming income.

The California Right to Farm Act under Civil Code 3482.5 protects established agricultural operations from nuisance lawsuits brought by neighbors who moved in after farming began. The law applies statewide and limits both private and local government nuisance actions.

California prohibits grocery stores and large retailers from providing single-use plastic carryout bags under Public Resources Code 42280-42288, enacted by SB 270 (2014) and ratified as Proposition 67 in 2016. Recycled paper or reusable bags require a 10-cent minimum charge.

California restricts expanded polystyrene food containers statewide through SB 54 (2022) packaging requirements under Public Resources Code 42040-42081. The law mandates that polystyrene foodware achieve 25 percent recycling by 2025 or face statewide sales prohibition.

California Public Resources Code 42270-42273, enacted by AB 1884 (2018), prohibits full-service restaurants from providing single-use plastic straws unless requested by the customer. The on-request rule applies uniformly to dine-in restaurants statewide.

California prohibits sale of tobacco and vapor products to anyone under 21 statewide under Business and Professions Code 22958, enacted by SBX2-7 in 2016. The Tobacco 21 standard applies uniformly across all California jurisdictions.

California bans retail sale of most flavored tobacco products statewide under Health and Safety Code 104559.5, enacted by SB 793 (2020) and upheld by voters via Proposition 31 in November 2022. The ban applies uniformly to all California retailers.

California requires statewide licensing of tobacco and vape retailers under the STAKE Act and the Cigarette and Tobacco Products Licensing Act. Business and Professions Code 22970 establishes uniform retailer licensing, while local governments may adopt stricter rules.