Agriculture Exempt (Ag-Exempt)

Introduction

This section explains the rules and definitions for agricultural buildings according to local building codes and ordinances. Agricultural exempt buildings are designed specifically for agricultural storage and operations and are not open to the public or used for residential purposes. In contrast, residential accessory greenhouses are smaller structures intended for personal horticulture, located on residential properties.

Key Terms

Agricultural Exempt Buildings

Defined under Section 202-A of the Uniform Building Code and further elaborated by local ordinances (HCC 331-11(a)(4)(8)), these structures are designed to support the agricultural industry by housing farm implements, hay, grain, poultry, livestock, or other horticultural products. They are characterized by:

• Usage Restrictions: Not intended for human habitation, public access, or as venues for processing, treating, or packaging agricultural products.
• Zoning and Location: Must be located on properties zoned for specific agricultural purposes such as Agriculture Exclusive, Agriculture General, Timberland Production, or similar designations that support agricultural activities as a principal use.
• Exemption: Agricultural exempt structures will be exempt from the structural requirements of the current building code, however, electrical, mechanical, plumbing, and energy code requirements will still apply.
• Permit Requirements: Apply for a regular building permit. See our Construction Documents webpage to see what submittal documents will be required for permit issuance (note that ag-exempt buildings will be considered a "new structure").

Residential Accessory Greenhouses

These are accessory buildings defined in HCC 314-137 as detached subordinate structures that are incidental to and located on the same lot as a principal building. Key details include:

• Size and Scope: Each legal parcel shall be allowed a maximum (2) 400 square foot residential accessory greenhouses used for horticulture of food for personal or domestic consumption and/or personal use cannabis.
• Exemption: Residential accessory greenhouses will be exempt from the structural requirements of the current building code, however,  current electrical, mechanical, plumbing, and energy code requirements will still apply.
• Permit Requirements: Apply for a regular building permit. See our Construction Documents webpage to see what submittal documents will be required for permit issuance (note that ag-exempt buildings will be considered a "new structure").

Requirements

The following requirements will apply to both Agricultural Exempt Buildings and Residential Accessory Greenhouses.

1. Site Inspection: A presite inspection will verify the use of the ag-exempt structure. See our Inspections webpage for more information.
2. Zoning: Ag exempt structures must meet zoning and land use requirements, including setbacks, height and lot coverage restrictions.
3. Electrical: Electrical service in ag exempt structures is limited to 100 amps, unless otherwise approved by the Chief Building Official. Electric installation shall comply with the current California Electric Code. Additionally, the following requirements will apply.
   • All electrical listed as suitable for use in wet locations.
   • All electrical wiring and equipment subject to physical damage shall be protected.
   • All electrical to be securely fastened and supported in accordance with current California Electric Code.
   • All 125-volt, single phase, 15 and 20amp general purpose receptacles to be GFCI protected.
   • Service equipment is identified as suitable for use as service equipment.
   • All electrical panel boards to be weatherproof and listed for damp/wet locations.
   • Verify grounding electrodes at each electrified, detached structure.
   • Solar snap fans and solar driver (panel) shall be installed per manufactures specifications and current California Electrical Code.
4. Plumbing: Plumbing elements are limited to hose bibs and must be in compliance with current California Plumbing Code. Ag-exempt structures cannot have a restroom, kitchen, or breakroom.
5. Mechanical: Mechanical elements must be in compliance with current California Mechanical Code and per the manufacturers installation instructions.
6. Energy: Ag exempt structures may be conditioned. “Conditioning” refers wood heating, mechanical heating that has a capacity exceeding 10 Btu/hr-ft2, or mechanical cooling that has a capacity exceeding 5 Btu/hr-ft2. See our Conditioned Greenhouses handout for more information.
7. Interior: Ag exempt structures can have insulation and wall coverings (6-mil plastic, plywood, drywall), but may not have finished interiors (taped, mudded or textured, painted, etc.)
8. Floor: Greenhouses located on lands zoned Agriculture Exclusive, Agriculture General, or Timberland Production may have restrictions on improved floors and footpaths (314-69.1.1.2).
   • A greenhouse located on prime agricultural soils shall not have an improved floor or footpath that precludes the use of the underlying soil. A footpath may be allowed with a Special Permit if constructed of asphalt, concrete or similar material.
   • A greenhouse located on non-prime agricultural soils may have an improved floor or footpath that precludes the use of the underlying soil if a Special Permit is obtained.
9. Use: Cannabis projects may use ag exempt structures for cultivation and drying only. Trimming, weighing and packaging are not allowed. Ag exempt structures (non-residential) may have employees, but the structure cannot be a place where agricultural products are processed, treated, or packaged.
10. Means of Egress: The maximum travel distance from any point in the ag exempt structure to an approved exit shall not exceed 300 feet. One approved exit (swinging 3-foot man door) required for each 15,000 square feet.

Size Limitations for Greenhouses

1. Single structure greenhouses or configurations/groupings of smaller greenhouses totaling 12,000 square feet or less must have minimum 20 foot setback to property line. State Responsibility Area setbacks of 30ft may apply.
2. Single structure greenhouses or configurations/groupings of smaller greenhouses totaling more than 12,000 square feet must have minimum 20 foot setback to property line AND 20 foot setback to other greenhouses.
3. A greenhouse or greenhouse grouping of any size is allowed with a 60-foot setback to the property line and 60 foot setback to other occupancies.

Ag-Buildings in the Flood Zone

Agricultural buildings in the flood zone shall provide a flood elevation certificate (FEC) for EACH structure. See the Flood Hazard page for more information on FEC's. The FEC will determine the base flood elevation, and all new construction and substantial improvement of any structure in a Special Flood Hazard Area (SFHA) shall have the lowest floor, including the basement, elevated to one (1) foot above the base flood elevation. Greenhouse and pole roof structures may be exempt from elevating one (1) foot above the base flood elevation if the development can meet the requirements of the Hoop House in the Flood Zone form. Additionally, temporary greenhouses and pole structures can be exempt from elevating 1ft above base flood elevation if the structures are removed between October 15th through April 16th per our Temporary Structures in the Flood Zone form. Existing ag-buildings and alterations to existing ag-buildings in the flood zone shall comply with our Substantial Improvements in the Flood Zone form.