Denver ADU permit requirements

Drawings accurately showing the scope and meeting health, safety, egress, fire, and structural code, with construction-document basics: address, legal description, design contact, seals/signatures, scope narrative, adopted-code list, scale/north arrow/legend.

Climatic/geographic design criteria and the GFA of each floor of every building including basements; GFA drives affordable-housing and permit fees.

Building volume and components: foundation type, structural members, attic volume/ventilation, stairs/ramps, windows/doors, space uses, and ceiling heights.

Completed Denver Energy Code Residential Compliance Checklist; ACCA Manual J, S, and D for new HVAC; plus the report for the chosen compliance pathway (REScheck / energy model / ERI).

Detail drawings for wall sections (member sizes, R-values, fire blocking, sheathing, finishes), foundation, roof, stairs, and site/retaining walls.

All existing + proposed structures, finished grade, overhang dimensions, fire-rated-wall opening analysis, height in feet/stories, bulk planes, upper-story setback/stepback, and rooftop mechanical screening.

Room uses, kitchens (full vs partial), plumbing fixtures, fire-rated walls/separations, ceiling height, egress path, emergency escape & rescue openings, glazing, ventilation, radon vent, and smoke/CO alarms.

A current soils report is required for new dwellings and conditioned accessory structures (which includes a new ADU), plus excavation and expansive-soil cases.

Attic ventilation calc, skylights/U-values, drainage, roof overhangs (with fire rating if within 5 ft of a line), roof slope, solar-ready zone, and radon-vent termination.

All development is reviewed by the SUDP team for sanitary, storm/grading, floodplain, groundwater, and ROW impacts; new ADU living space requires a SUDP.

Scaled plan dimensioning zone-lot lines, abutting streets/alleys/sidewalks, existing + proposed structures, driveways, setbacks, the 65/35 zone-lot depth line, spot grades, and tree/parkway details.

Complete load path to the foundation: load info, material strengths, foundation plans + reinforcement, framing plans, and calculations for all non-prescriptive elements.

Required for a new dwelling on vacant land; an Improvement Survey Plat is required for additions when a proposed exterior wall is within 3 ft of a lot line. ILCs are not accepted where a survey is required.

Zone district/overlays, building form and use of each structure, zone-lot area, and building coverage; for an attached ADU, must list the GFA used as the ADU.

Must be requested before permit application when adding a new dwelling unit, including attached or detached ADUs.

DRC structures require an excavation permit (issued separately) unless an exception applies; may require excavation plans, engineer-stamped shoring, soils report, and adjacent-owner affidavits.

Required before building/zoning permit approval if the property is a designated landmark or in a historic district.

Required when building an ADU in a Single-Unit zone district (except when built at the same time as the primary dwelling); submitted only when requested.