The Flathead County commissioners on Dec. 9 unanimously approved a contentious zoning amendment that will allow accessory dwellings in most county zoning districts.

Accessory dwelling units are defined as single, separate living units used for stays of 30 days or longer. Dwellings can be no larger than 40 percent of the floor area of the principal home on the property. Only one accessory dwelling can be rented per tract of record.

They will be allowed in county agricultural, suburban agricultural and some residential zoning districts as a permitted use, while such dwellings will be a conditional use in higher-density residential zones.

The Flathead County Planning Board discussed the idea of over the past year and a half as a way to preserve property rights, promote affordable housing and help homeowners financially.

Concerns over the zoning amendment came from several county residents as well as Citizens for a Better Flathead and the Whitefish County Water and Sewer District.

Last month, Citizens for a Better Flathead asked that the proposed amendment be sent back to the planning board for additional review. They cited a lack of definitions, standards, criteria for review and measurable goals.

In a letter to the county, the Whitefish County Water and Sewer District anticipated an increase in density in rural areas over time that could negatively impact water quality. Other public concerns referred to building heights, architectural building standards and impacts from short-term rentals.

On the other hand, several property owners in support for the amendment noted the financial benefit generated by a second dwelling on their property.

During discussion, commissioner Gary Krueger said he had heard that the zoning amendment “will change the face of the valley.

“I don’t see where that will happen,” he said. “We’re not going to see these mass-produced.”

The number of accessory dwellings in rural areas will be regulated through the septic permitting process, he said.

Commissioner Cal Scott agreed, pointing out the “multiple layers of review and approvals to restrict runaway” construction of accessory dwellings.

Commissioner Pam Holmquist said the amendment creates infill and shouldn’t override subdivision covenants governed by homeowner associations.

“I don’t believe it would be a free-for-all,” she said.

As for architectural review for construction in the county, Krueger said he’s “absolutely against” it.

“That’s been the status of citizens here for years and years,” he said.

If problems arise by allowing accessory dwellings, county zoning regulation could be revisited and changed, Krueger added.