Employers, developers and anyone looking to build homes or commercial space may soon have to comply with a 25 percent affordable housing mitigation rate if the county enacts an interim measure anticipated next month.

The Teton County Housing Authority is expected to present Teton County commissioners and Jackson Town councilors with a proposal to increase mitigation rates from 15 to 25 percent. Fees in lieu of providing the housing also would increase to 25 percent.

For businesses, that means 25 percent of their workers must have employee housing, while for developers it means 25 percent of dwellings in new projects must be affordable.

Executive Director Christine Walker said last week her agency likely will propose the increase as a way to address the shortage in affordable and employee housing while the county’s comprehensive plan is revised.

“I don’t think it will have a drastic effect either for developers or for our supply of affordable housing,” Walker said Tuesday.

The idea grew from a series of meetings the housing authority held with commissioners and councilors about a consultant’s housing needs assessment completed last summer. That report suggested increasing the affordable housing requirement for residential and commercial development from the current 15 percent to 40 percent to stem the flow of workers from the valley. The higher rate would ensure 60 percent of the workforce lives here, the percentage needed to keep a thriving community, consultants said.

Now, county regulations require residential developers to allocate 15 percent of their home sites to affordable housing units. That has been the regulation since 1994. Other resort communities have higher percentages. For example, Aspen’s Pitkin County, Colo., requires 60 percent.

Walker said this interim measure will be a good step to take while leaders are discussing that study and what recommendations they should adopt.

During the last presentation of the report, Jackson Mayor Mark Barron suggested the 25 percent in the interim.

“I said that to get this discussion moving forward,” Barron said Tuesday. “I think it is doable. I think it is a reasonable measure.”

He called it a “stopgap” that could address the housing shortage until town and county officials can have a broader discussion about affordable housing in their comp plan talks.

Though the Housing Authority has created more than 500 units since inception, demand for affordable homes has continued to increase as home prices soar. A recent report showed the median price of a single-family home was nearing $1.2 million.

Now, the agency has 819 units in its program: 361 ownership units and 458 rental and seasonal units. About 75 percent of those homes have been built since 2000, for a production of 125 units a year.

Still, the program needs more.

The Housing Authority just received 27 applications for an 810 West deed-restricted home up for resale and more than 70 for a home in the Millward subdivision earlier this summer.

Andy Schwartz, commission chairman, said last week he’s always felt it’s appropriate to have a 25 percent mitigation rate while the comp plan is being studied.

The housing needs assessment was performed by Economic & Planning Systems Inc., a Denver-based firm that specializes in land-use economics. Among the five pages of recommendations it makes for Jackson Hole’s affordable housing program, the firm also suggests Teton County should agree on what percentage of the local workforce it wants housed within the county lines. From there, the community can then determine how much of new residential development should be affordable.

The study can be accessed at www.tetonwyo .org/housing.