La Plata County, CO Accessory Structures: ADU Rules (2026)

Section 73-3 of the La Plata County Code allows additional dwelling units in conjunction with a principal single family residential dwelling unit, provided they meet the section's standards. The route depends on parcel size and use. No land use permit is required for a second dwelling unit on a parcel of at least seventy acres, or for a third on a parcel of at least one hundred and five acres.

Agricultural parcels can qualify for a director determination under the process in section 66-4: at least thirty acres for a second unit and forty-five acres for a third, assessed as agricultural in the most recent county assessment, with each unit meeting water quantity and quality standards under section 70-4, on-site wastewater treatment system standards under section 70-3, and driveway standards under chapter 74. A proposed central water or sewer system needs written documentation from the provider that it has capacity.

On a general residential parcel, one second unit can be approved by director determination if it shares the primary dwelling's electrical meter, water source, on-site wastewater treatment system, and access, and its livable floor area does not exceed the size of the primary dwelling unit or 2,000 square feet, whichever is less. It must meet the same water, wastewater, and driveway standards, and director determinations still meet the general approval criteria of section 66-16.

A parcel of at least six acres that is not eligible for a director determination can get one second unit through an administrative land use permit. A second or third unit that fits neither route needs a minor land use permit, and adding a fourth or more dwelling units requires a major land use permit under sections 66-7 and 66-21. Resolution No. 2022-01 amended the section, effective January 4, 2022.