When an accessory dwelling unit or junior accessory dwelling unit is proposed on a lot with an existing nonconforming residential structure that is nonconforming with regard to geologic setback, public view encroachment, coastal access, or habitat preserve buffers, and development of the proposed accessory dwelling unit or junior accessory dwelling unit does not result in redevelopment of the nonconforming residential structure. Pursuant to California Government Code Section
65852.2, the city shall not require, as a condition for approval of an accessory dwelling unit or a junior accessory dwelling unit, the correction of nonconforming zoning conditions, except where the accessory dwelling unit or junior accessory dwelling unit is located in the coastal zone and is attached to the nonconforming residential structure that is nonconforming with regard to geologic setback, public view encroachment, coastal access, or habitat preserve buffers, and will result in redevelopment of the nonconforming structure. For purposes of this section, redevelopment shall mean alterations to the residential structure resulting from construction of an accessory dwelling unit or junior accessory dwelling unit that consist of: (a) additions to an existing structure; or (b) exterior or interior renovations; or (c) demolition or replacement of an existing principal structure, or portions thereof, any of which results in replacement (including demolition, renovation or alteration) of fifty percent or more of major structural components including exterior walls, floor, roof structure or foundation, or a fifty percent increase in gross floor area.