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Marijuana Cultivation and Processing (Residential) in unincorporated Boulder County

Residential Marijuana Cultivation and Processing

Residential marijuana cultivation and processing is an accessory use to a residential use in unincorporated areas of Boulder County. Marijuana grown as part of this use is intended to be grown by and for those living on the parcel, not for sale or provision to others. This use does not allow growing marijuana as a home occupation. Only plants grown on the parcel may be processed on the parcel. A total of six plants are allowed to be grown per parcel. The Boulder County Land Use Code allows for this use in multifamily structures, but landlords, building owners and HOAs may set additional controls or disallow this use. Those cultivating or processing marijuana must also comply with Section 14 and Section 16 of Article XVIII of the Colorado Constitution and other applicable state law.

The following sections of the Boulder County Land Use Code were updated in June 2016:

Residential Marijuana Growing Regulations

  • Must be in a legal dwelling unit or accessory structure
  • Not for the purpose of sale or profit
  • Used by and for the individuals living on the parcel
  • Maximum of six (6) plants may be grown per legal dwelling unit
  • Processing of plants is limited only to those plants grown on the parcel
  • Use by right in all districts as long as there is a legal dwelling unit
  • Must not result in noise, vibration, light, odor, dust, smoke or particulate or other air pollution noticeable at or beyond the property line or shared dwelling unit wall
  • Plants shall not be cultivated, produced, processed or possessed in common areas of multi-family or attached residential developments

Residential Marijuana Extraction Regulations


  • Alcohol/ethanol extraction is permitted provided it is done without application of an open flame or open heat source and does not use more than 375ml of alcohol or ethanol during the extraction process.
  • Food-based extraction is permitted including production of marijuana concentrate by extracting cannabinoids from marijuana through the use of propylene, glycol, glycerin, butter, olive oil, or other cooking methods.
  • Water-based or dry-ice based extractions are permitted including production of marijuana concentrate by extracting cannabinoids from marijuana through the use of only water, ice, or dry ice.


  • Use of compressed, flammable gas as a solvent in the extraction of THC or other cannabinoids is prohibited.
  • Use of supplemental ozone is prohibited
  • Supplemental use of carbon dioxide is prohibited.

Please see Article 4-516(R) of the Boulder County Land Use Code for more information.


Definition of a Marijuana Establishment – Article 4-512(I)

  • Any location where more than six marijuana plants are cultivated, produced, tested or distributed.
  • Permitted by right in T, B, C, LI, and GI
  • Personal cultivation and Primary Caregiver cultivation facilities are limited to no more than 99 plants.

Definition of Primary Caregiver – Article 18-185B

  • A person who meets the definition of primary caregiver under article XVII, section 14(1)(f) of the Colorado constitution and applicable laws.

Health and safety concerns

These regulations were developed to address health and safety impacts of residential marijuana cultivation and processing. The following summary outlines the potential impacts of not following these regulations along with general health information regarding marijuana use.

  1. Fires and Explosions: Since the lighting needed to grow marijuana indoors is energy intensive, fires and explosions can result from overloading a power system with more than the six plants allowed in the Boulder County Land Use Code. Using flammable or combustible materials in extraction can also lead to fires and explosions.
  2. Mold: To help prevent mold growth, use materials such as plastic or painted concrete for walls as they do not absorb water easily. Make sure your space has adequate ventilation as well.

Additional health and safety resources

Boulder County Public Health website – Information on the impacts of use by youth (impaired learning and mental health risks); pregnancy and breastfeeding; physical health; and a variety of resources

State of Colorado website – Information and resources on legal use; responsible use (storage, safety while impaired, infant care, edibles, growing at home, and secondhand smoke); medical use; and health effects (immediate, long-term, pregnancy/breastfeeding, youth, and addiction)

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