Building permits, zoning and land rules in Denver County, Colorado

Yes. Denver County requires permits for most construction, alteration or repair work on private property¹. Exempt finish work includes painting, papering, tiling, floor coverings, cabinets and like-for-like plumbing fixtures, but a zoning, wastewater or fire permit may still be needed even when no building permit is required⁹. Building work follows the 2025 Denver Building and Fire Codes, which incorporate the 2024 International Codes¹⁰. A certificate of occupancy is required for new one-family and two-family dwellings and other listed new or changed occupancies, with exceptions for detached private garages and non-habitable accessory structures¹¹. Permitted work must remain accessible for Denver's inspections until approved; the required inspections depend on the project and trades involved¹². An owner-occupier may pull a permit for a primary one-family dwelling, but not for a duplex, townhome, condo, apartment, commercial building or accessory dwelling; the owner must pass applicable trade exams and occupy the home for at least 12 months after the certificate of occupancy, and a new single-family home permit is available only once in any five-year period^5,13. Permits cannot be issued to trusts, LLCs or corporations⁵.

Denver Community Planning & Development (CPD) is the building department. Its line for detached homes and duplexes is 720-865-2710, and its office is on the second floor of the Webb Municipal Building at 201 W. Colfax Ave¹⁴.. For zoning interpretations, zone-lot amendments or variances involving a single-family or duplex project, contact CPD's Zoning Administration team at 720-865-2606¹⁴. Residential applicants use Denver's e-permits system, select Development Services and then Building Log for most projects, and upload the required documents; quick permits exist only for eligible work and are issued without plan review, and the sewer-use-and-drainage review starts automatically with the building-permit application⁵. Denver publishes building and land-development fee schedules because charges vary by permit and project; plan review is charged separately from the permit, and re-inspections can add a fee^1,12.

Yes. Zoning applies across the consolidated City and County of Denver, so there is no separate unincorporated area with different zoning rules². The Denver Zoning Code governs most properties, but Former Chapter 59 covers about 17% of the city, and site-specific PUDs, waivers or conditions can change the answer for a particular lot⁴. City staff review zoning-permit applications against the Denver Zoning Code, and some applications require public notice or Board of Adjustment review⁴. Setbacks, lot coverage, building height and minimum lot size therefore cannot be answered from the county name alone; ask CPD's Zoning Administration team to identify the controlling district and restrictions¹⁴. Denver allows one accessory dwelling unit for each primary dwelling unit where the zone district permits it, but an RV, mobile home or trailer cannot serve as the ADU⁷. Subdivision of land falls under Chapter 50 of the Denver Revised Municipal Code, and a zone lot can differ from the recorded subdivision lot and assessor's tax parcel, so confirm all three before assuming a parcel can be split or developed as shown on a listing².

Denver is largely served by public sewer, and new private on-site wastewater treatment systems (OWTS, what most people call septic) are generally prohibited inside Denver, with exceptions only for qualifying business, commercial, industrial or institutional uses or a granted variance³. Denver's Department of Public Health & Environment is the local agency that administers the rules, and the state Water Quality Control Division keeps authority to enforce Regulation 43 where needed³. A permit is required to operate an existing OWTS, to build a new one or to repair one³. No permit can be issued where the property abuts a street or alley with a city public sewer, for a new system serving a multifamily dwelling, or for a new system in a designated 100-year floodplain³. Every new system needs a final inspection by the department before use, though Denver requires no septic inspection when a property is sold³. Homeowners converting from septic to the sanitary sewer pay a $100 application fee plus separate sewer tap fees¹⁵. Colorado also conditions a building or occupancy permit on public sewer service or an approved OWTS process¹⁶. Call the department at 720-865-5484; septic permits do not come from the building or zoning staff at Community Planning & Development¹⁷.

A Colorado-regulated tiny home may be approved for long-term living after the Colorado Division of Housing approves its plans, but it must also satisfy Denver zoning for the installation site⁶. Denver permits ADUs only where the zone district allows them, and an RV, mobile home or trailer cannot be used as an ADU⁷. We could not confirm a general Denver rule allowing long-term residence in an ordinary RV on a residential lot, so ask CPD's Zoning Administration team before relying on one as housing¹⁴. An RV or travel trailer also cannot be used for a Denver short-term rental; a permitted short-term rental must operate in a dwelling unit and generally be run by someone whose primary residence is the primary dwelling or an ADU on the same zone lot⁷.

1. Ask CPD's Zoning Administration team which zoning code, district and site-specific conditions control the lot^4,14.
2. Confirm that the proposed structure, ADU and zone lot comply, and resolve any subdivision or zone-lot issue before design^2,7.
3. Check the regulatory floodplain map; any construction in Zones A, AE, AH or AO, even an interior remodel, needs a floodplain permit through the sewer-use-and-drainage review, and a final floodplain inspection must pass before a certificate of occupancy is requested^2,18.
4. Create an e-permits account, choose Development Services and Building Log for most projects, then upload the required documents⁵.
5. Use Denver's project-specific fee schedules and budget separately for plan review, the permit and any re-inspection; beginning work without a permit doubles the permit charge, subject to a $100 minimum and the stated emergency exception^1,12.
6. Keep permitted work exposed and accessible until Denver completes the required project and trade inspections¹².

Confirm the exact zoning code, district and any site-specific conditions before making an offer; the Denver Zoning Code governs most parcels, while Former Chapter 59 and special approvals govern others⁴. Compare the legal subdivision description, zone lot and assessor's parcel because they may not match². Check for a regulatory floodplain: any construction there, including an interior remodel, needs a floodplain permit, most floodway construction is prohibited, and residential floors must sit at least 18 inches above base flood elevation¹⁸. Do not count on a septic system: Denver generally prohibits new ones, and an existing system needs its own operating permit from Denver's public health department^3,17. Finally, budget for project-specific permit charges, separate plan-review and possible re-inspection charges, and an effective property-tax rate of about 0.4% with a median annual bill near $2,596^1,12,19.