San Bruno ADU Standards

Prefab ADU in San Bruno

What is an Accessory Dwelling Unit (ADU)?

An ADU is an independent residential unit on the same lot as a primary home, providing additional living space, rental income, or multi-generational housing. A prefab ADU is a permanent, factory-built backyard home that meets local zoning and building codes, making it ideal for long-term living.

Tiny homes, often confused with prefab ADUs, are small, mobile units built on wheels. While both can be ADUs, prefab ADUs are stationary and built to last, whereas tiny homes face more zoning challenges due to their mobility.

Planning to Build an ADU in San Bruno?

With new ADU regulations, San Bruno has seen an increase in ADU construction. If you’re considering building one, LiveLarge is here to guide you through key development requirements for a smooth and successful project.

Types of ADUs:

  • Attached ADU: Extension or conversion of an existing structure.
  • Detached ADU: A new, separate building.
  • Junior ADU (JADU): A unit up to 500 sq. ft. within an existing or proposed single-family home.

Zoning and Lot Size

ADUs are permitted in all residential zones. JADUs are allowed only within existing or proposed single-family residences.

Size and Floor Area

Attached ADU:

  • 0-1 Bedroom: Up to 850 sq. ft.
  • 2 Bedrooms:
    • Lots < 7,500 sq. ft.: Up to 1,000 sq. ft.
    • Lots ≥ 7,500 sq. ft.: Up to 1,200 sq. ft.

Detached ADU:

  • 0-1 Bedroom: Up to 850 sq. ft.
  • 2 Bedrooms:
    • Lots < 7,500 sq. ft.: Up to 1,000 sq. ft.
    • Lots ≥ 7,500 sq. ft.: Up to 1,200 sq. ft.

Setbacks and Height

  • Attached ADU: Setbacks: 4-foot side/rear setbacks. Height: 16 ft.
  • Detached ADU: Setbacks: 4-foot side/rear setbacks; 5 feet from the primary residence; front setback as per underlying zoning regulations. Height: 16 ft.
  • Conversion of Existing Area: No setbacks required for the conversion of an existing living area or accessory structure, or for a structure built in the same location and to the same dimensions as an existing structure converted into an ADU.
  • Junior ADU (JADU): Setbacks: 4-foot side/rear setbacks.

Parking Requirements

One additional parking space is required except when:

  • The ADU is within ½ mile of public transit.
  • It is in a historic district.
  • It is part of the existing or proposed primary residence or multi-family building.
    On-street parking permits are required but not available to ADU occupants.
    A car-share vehicle parking area is within one block.
  • The ADU qualifies under Gov. Code § 65852.2(e).

Garage/Carport Conversions: No replacement parking is required if a garage, carport, or covered parking is demolished or converted into an ADU.

Contact Information

For more details, contact the San Bruno Planning Division at (650) 616-7074 or Planning@sanbruno.ca.gov.

Why Choose LiveLarge Prefab ADUs?

LiveLarge Prefab ADUs are designed to meet San Bruno’s detached ADU regulations, offering a hassle-free way to increase property value. With pre-approved designs and expert guidance, we ensure a smooth approval process.

Let LiveLarge be your trusted ADU partner. With our expertise in design, construction, and pre-approved plans, we’ll help ensure your project meets local standards and maximizes your property’s potential. Contact us today to get started!

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