A conditional use permit shall be obtained for all commercial uses located in a residential zoning district.

No nonconforming use may be enlarged or expanded, except as otherwise provided in this chapter.

If any nonconforming use is discontinued for a period of ninety (90) days, any subsequent use of the land or structure housing such use shall conform to the regulations specified for the zoning district in which such land or structure is located.

A nonconforming use may be changed to another use of the same or more restrictive classification upon the securing of a conditional use permit therefor; however, a nonconforming use may not be changed to a less restrictive use.

Any use occupying a structure which is nonconforming because it does not satisfy the parking requirements for the zoning district in which it is located may be changed to a similar or more restrictive use, subject to the obtaining of a use permit therefor. A blanket use permit may be granted specifying one (1) or more potential future uses based on the actual parking available. Properties where required spaces have been eliminated due to compliance with the Americans with Disabilities Act or the electrical vehicle charging space requirement per Section 16.72.010 are not considered nonconforming in regard to parking for purposes of this section.

Except as otherwise provided in this chapter, nonconforming structures may continue and may be maintained, repaired, altered and expanded, provided that no increase in the nonconformity results, all other applicable regulations are met, and the cost of such maintenance, repair, alteration, and/or expansion, when expressed as a percent of replacement cost of the existing structure, shall not exceed in any twelve (12) month period the percentage shown in the following table for the applicable zoning district and project type, unless a conditional use permit is obtained.

Projects which have submitted a complete application for a discretionary land use entitlement or building permit prior to July 18, 2006 shall be exempt from the provisions of this chapter, provided the project obtains a use permit or building permit within one (1) year from such date, or such further extended date approved by the planning commission. The planning commission may extend the effective date of this exemption upon the request of the applicant, if the planning commission finds that there is good cause for the extension of such one-year period based upon unusual circumstance and/or conditions not of the making of the applicant or its agents or employees.

Dwellings where electric equipment encroaches into the minimum required dimensions for garages or carports, as specified in Section 16.72.010, shall not be considered nonconforming with regard to minimum required parking.

Nonconforming uses that do not occupy a structure;

Nonconforming structures, or uses that occupy a structure with an assessed value of less than five hundred dollars ($500.00).

Types I and II buildings (fire resistive), forty (40) years;

Type III buildings (heavy timber and ordinary masonry), thirty (30) years;

Types IV and V buildings (light incombustible frame and wood frame), twenty-five (25) years;

Any other type of building, twenty (20) years.

All buildings in existence or approved as of the date of adoption of the ordinance codified in this section, on the twenty-fifth day of November, 1986, and all buildings thereafter constructed in accordance with a master site plan approved as of said date of adoption shall be exempt from the floor area ratio requirements established by said ordinance provided that this exemption shall not apply to an increase in the gross floor area of a building by addition to or expansion of the building unless such addition or expansion was constructed or approved prior to said date or is in accordance with a master site plan approved prior to said date. For purposes of this section, a building shall be considered to be in accordance with a master site plan if the total gross floor area of all buildings located on the property governed by the master site plan does not exceed the total gross floor area of all buildings planned for such property under the master site plan.

No building exempt under subsection (a) of this section shall be subject to amortization by reason of a nonconformity to a floor area ratio requirement established by said ordinance.

Any building exempt under subsection (a) of this section may be restored to its condition at the time of destruction if the building is destroyed by fire, explosion, or other catastrophe but such restoration shall comply with:

Any building exempt under subsection (a) of this section may undergo removal on one or more occasions following said date of adoption of a cumulative total of not more than fifty percent of its gross floor area and the replacement of part or all of the portions removed. The exemption shall terminate upon the removal or replacement on one or more occasions of a cumulative total of more than fifty percent of the gross floor area of the building.

Except as provided in this subsection, any building exempt under subsection (a) of this section may undergo interior improvements to the building if there is no increase in the gross floor area. A building in the M-2 district shall not be exempt from the floor area ratio requirements resulting from conversion of interior space from any other existing use to office use.

Notwithstanding the foregoing, the square footage of an exempt building shall be considered in determining whether a nonexempt building shall be permitted on the site occupied by the exempt building.

All buildings and office uses in existence or approved as of the date of adoption of the general plan amendment to the land use and circulation elements, on the first day of December, 1994, shall be exempt from the floor area ratio reduction from forty percent (40%) to thirty percent (30%) in the C-1 district, the floor area ratio reduction for office use from one hundred percent (100%)—two hundred percent (200%) to fifty percent (50%) in the C-3 district, and the floor area ratio reduction for office use from fifty percent (50%)—seventy-five percent (75%) to forty percent (40%) in the C-4 El Camino Real district; provided, that this exemption shall not apply to an increase in the gross floor area of a building by an addition or expansion of the building unless such addition or expansion was constructed or approved prior to said date.

No building or office use exempt under subsection (a) of this section shall be subject to amortization by reason of a building or office use which is nonconforming due to the floor area ratio reductions specified in subsection (a) of this section.

Any building or office use exempt under subsection (a) of this section may be restored to its condition at the time of destruction if the building or office use is destroyed by fire, explosion or other catastrophe, but such restoration shall comply with:

Any building or office use which is exempt under subsection (a) of this section may undergo removal on one or more occasions following said date of adoption of a cumulative total of not more than fifty percent (50%) of the gross floor area and the replacement of part or all of the portions moved. The exemption shall terminate upon the removal or replacement on one or more occasions of a cumulative total of more than fifty percent (50%) of the gross floor area of the building or office use.

Except as provided in this subsection, any building or office use exempt under subsection (a) of this section may undergo interior and/or exterior improvements to the building or office use if there is no increase in the gross floor area.

Notwithstanding the foregoing, the square footage of a building or office use exempt under subsection (a) of this section shall be considered in determining whether a nonexempt building or office use shall be permitted on the site occupied by the exempt building.

The following buildings shall be exempt from the Gross Floor Area Definition Clarification in Ordinance No. 963, provided that this exemption shall not apply to an increase in the gross floor area of a building by an addition or expansion of the building unless such addition or expansion was constructed or approved prior to said date:

No building exempt under subsection (a) of this section shall be subject to amortization by reason of a building which is nonconforming due to the Gross Floor Area Definition Clarification specified in subsection (a) of this section.

Any building exempt under subsection (a) of this section may be restored to its condition at the time of destruction if the building is destroyed by fire, explosion, or other catastrophe, but such restoration shall comply with:

Except as provided in this subsection, any building exempt under subsection (a) of this section may undergo interior and/or exterior improvements to the building if there is no increase in the gross floor area unless the increase in gross floor area is mandated to comply with required disabled access improvements and then only to the extent reasonably required to comply with such access requirements.

Regardless of what is set forth in subsections (a) through (d), the square footage of a building exempt under subsection (a) of this Section shall be considered in determining whether a nonexempt building or expansion of any building shall be permitted on the site occupied by the exempt building, except as provided in this subsection (e). If a building was built prior to the effective date of the Gross Floor Area Definition Clarification or received the necessary approvals to be exempt under subsection (a)(2) or (a)(3) of this Section and the building's gross floor area is greater than what it would be when measured pursuant to the Gross Floor Area Definition Clarification, the property owner may apply for a Gross Floor Area Exemption Certification to identify the gross floor area of a building that may be excluded from future calculations subject to the certification process outlined below. Upon receipt of a Gross Floor Area Exemption Certification, the gross floor area identified in the certification shall be excluded from future calculations of gross floor area for purposes of considering construction of new buildings or expansion of existing buildings on the property covered by the certification, except as otherwise provided in this subsection (e).

All buildings in existence or approved within the SP-ECR/D district as of the date of adoption of the El Camino Real/Downtown specific plan, on June 12, 2012, shall be exempt from the development standards of El Camino Real/Downtown specific plan.

No building exempt under subsection (a) of this section shall be subject to amortization by reason of a building that is nonconforming due to the development standards of the El Camino Real/Downtown specific plan specified in subsection (a) of this section.

Any building exempt under subsection (a) of this section may be restored to its condition at the time of destruction if the building or office use is destroyed by fire, explosion, or other catastrophe, but such restoration shall comply with:

Any building which is exempt under subsection (a) of this section may undergo removal on one (1) or more occasions following said date of adoption of a cumulative total of not more than fifty percent (50%) of the gross floor area and the replacement of part or all of the portions removed. The exemption shall terminate upon the removal or replacement on one (1) or more occasions of a cumulative total of more than fifty percent (50%) of the gross floor area of the building.

Except as provided in this subsection, any building exempt under subsection (a) of this section may undergo interior and/or exterior improvements to the building if there is no increase in the gross floor area.

Properties within the SP-ECR/D district that are regulated by a use permit, conditional development permit (CDP), or planned development (P-D) permit as of the date of adoption of the El Camino Real/Downtown specific plan on June 12, 2012, shall continue to be regulated by said permit(s). Such permit(s) shall lapse upon comprehensive redevelopment of the property, or property owners may apply to modify or cancel said permit(s) in accordance with the requirements of this title.

All buildings in existence or approved within the O (office), LS (life sciences), and R-MU (residential mixed use) districts as of the date of adoption of the ConnectMenlo General Plan and M-2 Area Zoning Update and the subsequent rezoning of properties in the M-2 Area, effective on January 5, 2017, shall be exempt from the development standards of the zoning districts identified in this section.

No building exempt under subsection (a) of this section shall be subject to amortization by reason of a building that is nonconforming due to the development standards of the O (office), LS (life sciences), and R-MU (residential mixed use) districts, as specified in subsection (a) of this section.

Any building exempt under subsection (a) of this section may be restored to its condition at the time of destruction if the building or office use is destroyed by fire, explosion, or other catastrophe, but such restoration shall comply with:

Properties within the O (office), LS (life sciences), or R-MU (residential mixed use) district that are regulated by a use permit or conditional development permit (CDP) as of the date of adoption of the ConnectMenlo General Plan Update and subsequent rezoning of properties in the M-2 Area, effective on January 5, 2017, shall continue to be regulated by said permit(s). Such permit(s) shall lapse upon comprehensive redevelopment of the property, or property owners may apply to modify or cancel said permit(s) in accordance with the requirements of this title.

Properties within the C-MU district that are regulated by a use permit or conditional development permit (CDP) as of January 4, 2024, shall continue to be regulated by said permit(s). Such permit(s) shall lapse upon comprehensive redevelopment of the property, or property owners may apply to modify or cancel said permit(s) in accordance with the requirements of this title.

No building exempt under subsection (a) of this section shall be subject to amortization by reason of a building that is nonconforming due to the development standards of the C-MU district, as specified in subsection (a) of this section.

Any building exempt under subsection (a) of this section may be restored to its condition at the time of destruction if the building or office use is destroyed by fire, explosion, or other catastrophe, but such restoration shall comply with: