Teton County considers rules to prevent 10,000-square-foot homes on small family subdivisions

Updates are part of a larger proposal to change some rules in rural areas.

JACKSON — Though state law limits how Teton County can regulate family subdivisions in rural areas, officials are considering limiting the size of houses on small, newly divided parcels of land.

In 2021, a Fish Creek Road landowner carved off a 0.5-acre parcel from their 4.9-acre plot of land using a Wyoming law meant to help ranching families split up their property, allowing kids to stay on the ranch in a home of their own. The 0.5-acre lot is the smallest parcel created in Teton County using the law, according to planners. County regulations, however, allow for a 10,000-square-foot home on the land.

That’s about four times the size of a standard American home. If that building was entirely contained on one floor, it would take up almost half the lot.

That’s too big, said Mark Newcomb, chair of the Teton County Board of County Commissioners.

“It would be completely out of character,” Newcomb said. “We would have expanses of agricultural land and then a pocket of houses that look like something out of the East Hamptons.”

What is family subdivision?

The family subdivision exemption is a long-standing Wyoming law. 

But, in response to a proliferation of subdivisions, between 2007 and 2019 Teton County started blocking landowners from using the tool on parcels smaller than 35 acres by withholding building permits. Families could subdivide, but could not build. 

In 2019, Wyoming lawmakers took notice and passed a law forcing the county to issue those landowners building permits.

Jackson Hole and Alta landowners have begun using the exemption again to the chagrin of some conservationists, who have argued the law allows those families to chop up rural lands.

Between 2019 and 2025, landowners have used the tool 27 times to create 52 new parcels, according to county planning staff. Thirty-eight of those parcels are in the county’s most rural areas, zoned R-1 and R-2. Twenty-six of those 38 parcels are less than 3 acres.

County planners are now proposing that lots smaller than 6 acres created during or after 2019 in the R-1 and R-2 zones use regulations for the less rural R-3 zone.

On a 5-acre parcel, a landowner could still build a 10,000-square-foot home. But on a 4-acre parcel, a landowner could only build a 9,475-square-foot home. On a 2-acre parcel, a landowner could build a 6,687-square-foot home.

Family members must hold the property for five years before selling or further subdividing it. Families can subdivide their property into lots smaller than 5 acres, but cannot further subdivide a property once it’s less than 5 acres.

Big homes use a lot of resources and require a lot of workers to build and maintain them, Commissioner Len Carlman said at a Monday workshop about the proposed change, as well as other tweaks for Teton County’s rural land development regulations.

“Building more and more bigger homes just puts more stress on service providers and our local community workforce,” Carlman said.

The Jackson Hole Conservation Alliance is in favor of reducing the maximum house size on small lots created by the family subdivision exemption, Executive Director Jenny Fitzgerald said.

Many “lavish homes” use an “exorbitant amount of resources” but sit empty for much of the year, Fitzgerald said.

“We have a housing shortage and many of those services are going to empty homes,” she said.

Commissioners did not make changes to the rural rules Monday.

County officials are instead planning to send proposed rule changes to the Planning Commission for review. Afterward, county commissioners will have the final say, hopefully by June, Newcomb said.

Other proposals

The county’s last overhaul of its land use regulations for rural areas was in 2016, when permitting effectively prevented family subdivision exemption.

County officials are aiming for a thorough update of the regulations now that family subdivisions are back on the table.

As it stands, the county has three tools offering density bonuses for landowners if they set aside swaths of land for conservation. The problem: Landowners have hardly used them.

Those tools are called “floor area option,” the “rural planned residential development” and the “complete neighborhood planned residential development.” Each offers density incentives in exchange for setting aside land for conservation.

Between 2016 and 2025, landowners have used the floor area option eight times. In the same period, no one has used the other two tools. That’s because the family subdivision exemption is a sweeter deal.

“The family subdivision exemption provides a significant and attractive alternative,” planners wrote in a staff report for Monday’s workshop.

County planners are aiming to tweak the floor area option tool to get more land for conservation out of it. They also want to ax the other two.

This story was published on Feb. 25, 2026.