Burlingame Municipal Code contains the details of requirements for ADUs.  See Chapter 25.59.

General Provisions Summary:

This section allows an accessory dwelling unit, either attached to the main dwelling or detached in a separate structure to be created on lots which now contain one single-family dwelling and meet the following criteria, upon approval of an administrative accessory dwelling unit permit.

(a)    Minimum Lot Size. The minimum lot size to accommodate an accessory dwelling unit shall be no less than six thousand (6,000) square feet; except for accessory dwelling units constructed prior to January 1, 1954.

(b)    There shall be no more than one accessory dwelling unit permitted on a lot which contains no more than one primary single-family dwelling.

(c)    Occupancy Restrictions. Either the primary single-family dwelling or the accessory dwelling unit shall be occupied as the principal place of residence of the record owner of the lot. In the case of ownership by a corporation, partnership, trust or association, either the primary single-family dwelling or the accessory dwelling unit shall be the place of residence of an officer, director or shareholder of the corporation, a partner in the partnership, a trustor, trustee or beneficiary of the trust, a member of the association, or an employee of any such organization.

(d)    Unit Size. The floor area of the accessory dwelling unit shall not exceed six hundred forty (640) square feet.

(e)    Floor Area Ratio. The accessory dwelling unit shall fall within the total floor area ratio and lot coverage allowed by the underlying zoning district.

(f)     Other Measurable Standards.

(1)    For attached units, the accessory dwelling unit shall comply with the setback, height and declining height envelope regulations which apply to the main dwelling unit.

(2)    For detached units, the accessory dwelling unit shall comply with the setback, height and window placement criteria for accessory structures contained in Chapter 25.60, and shall meet the setback requirements, including exceptions for accessory structures, contained in Sections 25.26.072 and 25.26.073. Detached units shall be limited to one story in height.

(g)    Parking. On-site parking spaces based on the number of bedrooms in the primary dwelling as required by Chapter 25.70 and parking requirements for an accessory dwelling unit shall be as follows:

(1)    Unless otherwise provided in this section, a minimum of one off-street uncovered parking space shall be provided for the accessory dwelling unit in addition to the off-street covered and uncovered parking spaces required for the main dwelling.

(i)     Parking for the accessory dwelling unit may be in tandem with a required parking space for the primary dwelling, meaning one car located directly behind another car; and

(ii)    No required parking may be provided in the front setback or yard, except in the driveway; and

(iii)   All parking shall be provided on a hard, all-weather surface and properly drained to the public street.

(2)    No parking space shall be required for an accessory dwelling unit in any of the following instances:

(i)     No on-site parking for the second unit shall be required if the accessory dwelling unit is only used for “affordable housing” as defined in Chapter 25.63. As a condition of approval under this subsection, the owner of the property will be required to enter into and record an agreement generally in conformance with Section 25.63.040 to ensure continued affordability of the accessory dwelling unit. A draft agreement shall be required at the time of application submittal.

(ii)    The accessory dwelling unit is located within one-half mile of a major transit stop, as defined in California Public Resources Code Section 21064.3 or included in the regional transportation plan;

(iii)   The accessory dwelling unit is located within a designated historic district;

(iv)   The accessory dwelling unit is part of the existing main residence or an existing, authorized and finalized residential accessory structure intended for human habitation as having existed three (3) years prior to application;

(v)    When on-street parking permits are required but not offered to the occupant of the accessory dwelling unit;

(vi)   When there is a car share vehicle, in a location determined by the Community Development Director to have at least three (3) dedicated parking spaces, located within one block of the accessory dwelling unit;

(h)    Construction of the accessory dwelling unit shall comply with the all applicable provisions of this title and all applicable building, health and fire codes; except for accessory dwelling units constructed prior to January 1, 1954;

(i)     The accessory dwelling unit shall incorporate the same or similar architectural features, building materials and colors as the primary dwelling located on the property. Compatibility with the primary structure includes coordination of colors, materials, roofing and other architectural features, and landscaping designed so that the appearance of the site remains that of a single-family residence.

City of Burlingame

City of Burlingame Planning Division

City of Burlingame Building Division