California ADU rules · San Mateo County
Can I Build an ADU in Burlingame?
Yes — you can build an ADU in Burlingame. California's statewide ADU law requires every city, including Burlingame, to approve a qualifying accessory dwelling unit by right, plus a junior ADU (JADU) on a single-family lot. What varies city to city are the local specifics below.
Can you build one?
ADUs allowed
CA state lawYes — by right
ADUs and JADUs are allowed by right in all residential and mixed-use zones; ministerial approval, no hearing.
Units on a single-family lot
CA state law1 ADU + 1 JADU
At least one ADU and one JADU per single-family lot (a conversion ADU may also be possible).
Units on a multifamily lot
Local ruleconversions (>=1 or 25% of units); up to 8 detached (or as many as primary units, whichever is less, if converted from existing detached garages); up to 2 detached for new multifamily dwellings
Detached ADUs on multifamily lots are capped at 8 or the number of primary units if converted from existing detached garages; only 2 detached ADUs allowed for new multifamily dwellings.
Junior ADU (JADU)
CA state lawAllowed
Up to 500 sq ft, within the walls of an existing single-family home (single-family lots only).
Size & height
Max detached ADU size
Local rule1,000 sq ft
Local maximum for detached ADUs is 1,000 sq ft; state minimum of 800 sq ft still applies.
Max attached ADU size
Local rule1,000 sq ft cap (state minimum 800 sq ft always allowed)
Attached ADUs are capped at 1,000 sq ft, but at least 800 sq ft must be allowed.
Guaranteed minimum size
CA state law800 sq ft
An 800 sq ft ADU must be allowed regardless of FAR/lot-coverage caps; a city also cannot cap an attached ADU below 850 sq ft (1,000 for 2+ bedrooms).
Max JADU size
CA state law500 sq ft
Max height
CA state law16 ft
16 ft baseline; cities must allow 18 ft within ½ mi of a major transit stop or where the primary dwelling is two-story, and 20 ft on a lot with a multistory multifamily building.
Setbacks
Side setback
CA state law4 ft
A city cannot require more than 4 ft side or rear setback; conversions of existing structures are exempt.
Rear setback
CA state law4 ft
Front setback
Local ruleNo front setback may preclude an 800 sq ft ADU with 4-ft side/rear setbacks; ADUs >800 sq ft must meet standard front setback
Front setback cannot block a compliant 800 sq ft ADU; larger ADUs must meet standard front setback.
Separation from main house
CA state lawNone required
No statewide separation requirement between the ADU and the primary dwelling.
Parking
Parking required
CA state lawUp to 1 space
At most 1 space per ADU (or per bedroom, whichever is less) — and waived in the common cases below.
Transit parking exemption
CA state lawYes — no parking required near transit & for conversions
No parking may be required within ½ mi walking distance of transit, in a historic district, for an ADU within an existing structure, within one block of car-share, or in certain permit-parking areas.
Garage-conversion replacement parking
CA state lawNot required
When a garage/carport is demolished or converted to build an ADU, replacement parking cannot be required.
Approval, timeline & cost
Approval path
CA state lawMinisterial (by right)
No public hearing or discretionary design review for a qualifying ADU.
Approval timeline
CA state law60 days
The agency must act within 60 days of a complete application — and the ADU is deemed approved if it does not.
Owner-occupancy
Local ruleNot required
No owner-occupancy required for ADUs; JADUs require owner-occupancy only if sharing sanitation.
Impact-fee waiver
CA state lawWaived under 750 sq ft
An ADU of 750 sq ft or less pays no impact fees (the 750 sq ft threshold itself is exempt under § 66311.5); larger ADUs pay fees proportional to the primary dwelling. JADUs (≤ 500 sq ft) are exempt.
Permits required
CA state lawBuilding permit
Only a ministerial building permit — no conditional use permit or discretionary design review for a qualifying ADU.
Burlingame-specific factors that can change the answer
State law sets the floor, but these local conditions often decide whether a specific parcel works.
Historic District
No ADU-specific restrictions, but historic district status may affect design/review.
Hillside Overlay Zone
Attached ADU height limited to 25 ft in Hillside Overlay Zone.
Burlingame caps both attached and detached ADUs at 1,000 sq ft, with a lower height limit for attached ADUs in the Hillside Overlay Zone. Up to 8 detached ADUs may be allowed on multifamily lots if converted from existing detached garages.
Frequently asked questions
Can I build an ADU in Burlingame?
Yes. California's statewide ADU law requires Burlingame to approve a qualifying accessory dwelling unit ministerial (by right), plus a junior ADU (JADU) on a single-family lot.
How big can an ADU be in Burlingame?
A detached ADU of at least 1,000 sq ft must be allowed, and an ADU of 800 sq ft can never be zoned out by floor-area or lot-coverage limits. A JADU can be up to 500 sq ft.
What are the setback requirements for an ADU in Burlingame?
Side and rear setbacks are limited to 4 ft. No front setback may preclude an 800 sq ft ADU with 4-ft side/rear setbacks; ADUs >800 sq ft must meet standard front setback.
Is parking required for an ADU in Burlingame?
Up to 1 space. No parking can be required within ½ mile of transit, for conversions, or for units inside the primary home. When a garage is converted, replacement parking is not required.
How long does ADU approval take in Burlingame?
A complete application must be acted on within 60 days, with ministerial (by right) — no public hearing or discretionary design review for a qualifying ADU.
Do I have to live on the property to build an ADU in Burlingame?
Owner-occupancy: not required. ADUs under 750 sq ft are also exempt from impact fees.
Sources
- Burlingame Municipal Code § 25.48.030
- § 25.48.030(E)(9)-(10)
- § 25.48.030(F)(1)-(2)
- § 25.48.030(F)(3)
- § 25.48.030(E)(3)(c), (G)(5)
- § 25.48.030(H)(2)
- § 25.48.030(F)(4)(d)
- Cal. Gov. Code §§ 66310–66342 (ADU Law)
- HCD 2025 Accessory Dwelling Unit Handbook
- Cal. Gov. Code § 66317 (ministerial approval, 60-day deadline)
- Cal. Gov. Code § 66323 (by-right ADU/JADU, 800 sq ft, 4-ft setbacks)
- Cal. Gov. Code § 66333 (junior ADUs)
- Cal. Gov. Code § 66321 (size minimums & height)
- Cal. Gov. Code § 66322 (ADU parking; § 66334 covers JADU parking)
- Cal. Gov. Code § 66314 (local ordinance standards)
- Cal. Gov. Code § 66311.5 (impact fees: none for an ADU ≤ 750 sq ft or JADU ≤ 500 sq ft)
Last updated 2026-06-25. This is an AI-assisted summary of Burlingame's ADU rules, drawn from its published ordinance and California ADU law — general information, not legal advice, and it may be incomplete or out of date. Verify the controlling rule for your specific parcel with Burlingame Planning before relying on it.
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