What changed, and when.
Every rule change we have recorded for the jurisdictions we cover, newest first. Each entry links the official page it came from.
Unincorporated Boulder County
County building code moves to the 2021 I-Codes
Permit applications from this date use the 2021 I-Codes plus county amendments for energy, sustainability and ignition resistance.
Building Code Amendments (Boulder County, opens in a new tab)State of Colorado
SB25-002 factory-built structure rules take effect
The Division of Housing’s administrative rules for factory-built structures took effect, and the division is still updating its forms.
Factory-Built Structures (State of Colorado, opens in a new tab)Unincorporated Boulder County
Commissioners authorize the ADU rewrite, docket DC-26-0002
The Board of County Commissioners authorized a Land Use Code update reconsidering the accessory dwelling rules.
DC-26-0002: Accessory Dwelling Units (Boulder County, opens in a new tab)State of Colorado
HB24-1152 compliance deadline for covered jurisdictions
Jurisdictions covered by the state ADU law were required to be in compliance by this date.
Accessory Dwelling Units (State of Colorado, opens in a new tab)City of Boulder
Updated ADU rules apply to new proposals
The city’s updated ADU rules apply to ADUs proposed on or after this date, including the end of the owner-occupancy requirement.
Accessory Dwelling Units (City of Boulder, opens in a new tab)City of Boulder
All-electric energy code takes effect for new construction
The 2024 city energy code requires new homes and additions to be all-electric, with no residential exceptions.
2024 City of Boulder Energy Code Update: Frequently Asked Questions (City of Boulder, opens in a new tab)
Looking for the rules themselves? See City of Boulder or Unincorporated Boulder County.
This page summarizes public rules for general information. It isn’t legal advice or a permit determination. Confirm requirements for your property with the City of Boulder or Boulder County before you design or build.
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