About five blocks separate Angel Garcia’s four-bedroom West Kendall townhouse from farmland, placing him on the western edge of Miami-Dade County’s suburbs. But for how long?

A proposed change in how the county measures long-term housing demand could clear the way for hundreds of townhomes on nearby farms facing Southwest 167th Avenue.

That would mean a new supply of lots for a county with a dwindling pipeline of new single-family houses, but a loss for environmentalists urging Miami-Dade to maintain the agricultural buffer between the Everglades and large-scale development.

Then there’s Garcia, who dreads the idea of more suburban commuters moving in west of him.

“If you don’t leave at five o’clock in the morning, basically you’re tied up in gridlock on Kendall Drive for 45 minutes to an hour,” said Garcia, 59, a mortgage broker and property manager who has lived in the area for more than 25 years. “If there’s going to be more construction, you’re going to have more issues.”

On Thursday, county commissioners are scheduled for a committee vote on legislation that could decide whether construction can expand west from the suburbs into farmland controlled by developers across Miami-Dade.

The resolution by the commission’s chairman, Jose “Pepe” Diaz, would change county policy on when to expand the Urban Development Boundary, the line that divides farmland from commercial complexes and residential subdivisions.

Current policy allows the UDB to stay in place as long as there is enough land inside the urban area to build new homes to meet 10 years of projected population growth and buyer demand.

County forecasts show enough land now to build more than 20 years worth of new homes across Dade, with about 260,000 residential units projected to be in the pipeline. About 90% of those would be built in mid-rise and high-rise apartment and condo buildings, according to a 2021 county analysis.

The Diaz policy change would alter the county’s growth formula to segregate “multi-family” residential land (the category that covers apartments and condos) and “single-family” residential land (the category that covers houses and townhomes).

The item would also set a goal of having enough land reserved for single-family projects to meet at least 10 years worth of demand — a benchmark that county planners say Miami-Dade can’t come close to satisfying with property inside the UDB.

That would mean a green light for developers who have already proposed new subdivisions outside Kendall and beyond, on farmland that could be converted to houses if Miami-Dade commissioners agreed to expand the UDB to include their properties.

“If adopted, a perpetual 10-year single-family mandate would all but guarantee the depletion of all agricultural land within 40-50 years,” Mayor Daniella Levine Cava wrote in a memo to commissioners this week. “This provision would quickly lead to the ‘tipping point’ after which agriculture could not be sustained as a vital part of our county economy...”

The Diaz legislation on the agenda for the 3 p.m. meeting of the Infrastructure, Operations and Innovation Committee represents the latest clash over responsible growth in Miami-Dade and the role that the UDB should play in preserving existing suburban boundaries.

In September, commissioners forwarded to the state a request to expand the UDB near Homestead for a 9-million-square-foot industrial park that would be built on farmland. A final vote is expected this year.

Last spring, commissioners balked at a proposal by Commissioner Kionne McGhee to move the UDB for a different industrial hub in South Miami-Dade.

Backers of the Diaz plan call it a reasonable response to Miami-Dade’s hot housing market, in which the median price for existing single-family homes soared 15% last year to $525,000, according to the Miami Association of Realtors. With most land zoned for multi-family projects (the category that covers apartments and condominiums), builders have limited options for constructing new houses.

“All I’m doing is responding to the need,” Diaz said in an interview. “We’re running out of space.”

Along with mandating a 10-year supply of land for single-family homes, Diaz’s legislation urges changes in county rules to make it easier to split existing lots and add backyard homes for family members.

Opponents argue the legislation would worsen Miami-Dade’s shortage of apartments and condos in a county where most residential land is already occupied by houses.