Coeur d'Alene, ID Accessory Structures: ADU Rules (2026)

Section 17.06.650 B of the Coeur d'Alene Municipal Code permits accessory dwelling units within all Residential and Commercial Zoning Districts, subject to the provisions of the Code. The stated purposes include rental income through tenants in either the ADU or the principal unit, added affordable units, and protecting the single-family appearance of the neighborhood.

Section 17.06.660 holds the development standards. Maximum height is thirty two feet (32') within the building envelope for the principal structure, eighteen feet (18') for a one story ADU in the rear yard, and twenty four feet (24') for an ADU over a detached garage in the rear yard, which must also meet the second story step back. Railings, parapets and equipment count toward height. Inside the principal building envelope the yards are twenty feet (20') front, five feet (5') interior side, ten feet (10') street side and twenty five feet (25') rear. In the rear twenty five feet of a lot the ADU sits at least five feet (5') from the side and rear lot lines, or three feet (3') from the rear line on an alley lot.

Size is capped at eight hundred (800) square feet of finished area, with no minimum, and an ADU cannot exceed seventy five percent (75%) of the primary dwelling's square footage, excluding garage area. One accessory dwelling unit is permitted per single-family dwelling, and combined occupants cannot exceed the number set for a family in § 17.02.055. The ADU cannot be subdivided or segregated in ownership from the principal unit. Attached units are limited to one ADU entrance on each front or street side, and additions must match the existing roof pitch, siding and windows. A detached garage or shed can be converted if it meets the current adopted Building Code, is not over the property line or in the right-of-way, and is not expanded without meeting current standards.

The second story step back starts at ten feet (10') of height on the interior side property line and fifteen feet (15') on the rear property line, at a 1:1 measurement, a forty five degree (45°) angle. Section 17.06.670 requires an application with an owner affidavit, a document recorded with the County Recorder that runs with the land, and allows City inspection with reasonable notice.