Development Definition for Geologic Purposes

What is Considered "Development" per the Geologic Hazards Ordinance

Completion of a Geologic Hazards Assessment (GHA) may be required for development or development activities, including foundation replacements or upgrades, in areas subject to potential geologic hazards. These areas include but are not limited to: fault zones, sites with suspected instability, and coastal hazard areas. The Geologic Hazards Ordinance (Section 16.10.040(s)) defines “Development/Development Activities” as follows:

1. The construction or placement of any habitable structure, including a manufactured home;

2. (Effective Within Coastal Zone) Modification, reconstruction or replacement of 65 percent of the major structural components—consisting of the foundation, floor framing, exterior wall framing, and roof framing—of an existing habitable structure within any consecutive five-year period, or modification, reconstruction or replacement of 50 percent of the major structural components of an existing critical structure or facility, as defined by this chapter, within any consecutive five-year period, whether the work is done at one time or as the sum of multiple projects. For the purpose of this section, the following are not considered major structural components: exterior siding; nonstructural door and window replacement; roofing material; decks; chimneys; and interior elements including but not limited to interior walls and sheetrock, insulation, kitchen and bathroom fixtures, mechanical, electrical and plumbing fixtures. The extent of alterations to major structural components will be calculated in accordance with administrative guidelines adopted by resolution of the Board of Supervisors;

2. (Effective Outside Coastal Zone) Modification, reconstruction or replacement of 50 percent of the major structural components—consisting of the foundation, floor framing, exterior wall framing, and roof framing—of an existing habitable structure within any consecutive five-year period, or modification, reconstruction or replacement of 50 percent of the major structural components of an existing critical structure or facility, as defined by this chapter, within any consecutive five-year period, whether the work is done at one time or as the sum of multiple projects. For the purpose of this chapter, the following are not considered major structural components: exterior siding; nonstructural door and window replacement; roofing material; decks; chimneys; and interior elements including but not limited to interior walls and sheetrock, insulation, kitchen and bathroom fixtures, mechanical, electrical and plumbing fixtures. The extent of alterations to major structural components will be calculated in accordance with administrative guidelines adopted by resolution of the Board of Supervisors;

3. The addition of habitable space to any structure, where the addition increases the habitable space by more than fifty (50) percent over the existing habitable space, measured in square feet. This allows a total increase of up to fifty (50) percent of the original habitable space of a structure, whether the additions are constructed at one time or as the sum of multiple additions during the life of the structure;

4. An addition of any size to a structure that is located on a coastal bluff, dune, or in the coastal hazard area, that extends the existing structure in a seaward direction;

5. Installation of a new foundation for a habitable structure;

6. The repair, replacement, or upgrade of an existing foundation of a habitable structure that affects more than fifty (50) percent of the foundation (measured in linear feet for perimeter foundations, square feet for slab foundations, or fifty (50) percent of the total number of piers), or an addition to an existing foundation that adds more than fifty (50) percent of the original foundation area. This allows repair, upgrade, or addition up to fifty (50) percent, measured as described above, whether the work is performed at one time or as the sum of multiple projects during the life of the structure;

7. A division of land or the creation of one or more new building sites, except where a land division is accomplished by the acquisition of such land by a public agency for public use;

8. Any change of use from non-habitable to habitable use, according to the definition of “habitable” found in Section 16.10.040, or a change of use from any non-critical structure to a critical structure.

9. Any alteration of any structure posted “Unsafe to Occupy” due to geologic hazards;

10. Grading activities of any scale in the 100 year floodplain or the coastal hazard area, and any grading activity which requires a permit pursuant to Chapter 16.20;

11. Construction of roads, utilities, or other facilities.

12. Retaining walls which require a building permit, retaining walls that function as a part of a landslide repair whether or not a building permit is required, sea walls, rip-rap erosion protection or retaining structures, and gabion baskets;

13. Installation of a septic system;

14. Any human made change to developed or undeveloped real estate in the Special Flood Hazard Area, including but not limited to buildings or other structures, mining, dredging, filling, grading, paving, excavation, drilling operations, or storage of equipment or materials. This is in addition to any activity listed in items 1-13.

15. Any other project that is defined as development under Section 13.20.040, and that will increase the number of people exposed to geologic hazards or that may create or exacerbate an existing geologic hazard, shall be determined by the Planning Director to constitute development for the purposes of geologic review.