The plan to upzone 27 Seattle neighborhoods could clear a key hurdle this afternoon

Following a contentious public hearing last week on Seattle’s plan for taller buildings and affordable-housing requirements in the urban cores of 27 neighborhoods and in some other areas, a special City Council committee is set to vote Monday.

The plan would upzone blocks across the city where apartments and commercial buildings are already permitted and would allow denser housing on about 6 percent of Seattle’s single-family lots, according to the city.

It also would trigger the city’s Mandatory Housing Affordability policy, which requires developers to support affordable housing, either by including some rent-restricted apartments in their projects or by paying into a city fund.

Proponents say the plan would harness the Seattle’s growth to produce thousands of units of low-income housing, while critics have raised concerns about the upzones crowding their neighborhoods and exacerbating gentrification.

Nearly all council members are expected to debate amendments in the committee led by Councilmembers Rob Johnson and M. Lorena González and to take part in Monday’s vote. The council’s final vote on the plan has been scheduled for March 18.

“We take action today to make up for lost time, for lost lives and for lost neighbors,” Councilmember Teresa Mosqueda said at a news conference before the committee meeting.

“Because Seattle has not built the housing that we need” to accommodate the city’s growing population, “we have seen our neighbors pushed out of Seattle and pushed into the streets,” she added.

By allowing apartments to be built on more lots, the upzones could chip away at residential segregation in Seattle, where patterns were set decades ago by redlining and by racist neighborhood covenants, Mosqueda said.

Some district-based council members want to scale back the proposed upzones on some blocks of single-family houses in West Seattle Junction, Wallingford and Crown Hill, claiming gentler changes are needed.

But González and Mosqueda, who represent the city at-large, have pushed back, arguing those amendments would cause fewer affordable and market-rate apartments to be constructed.

Council staffers have estimated the amendments in those neighborhoods would cost the city about 70 affordable apartments over the next 10 years, though other amendments could partly offset that loss.

González said she welcomes the upzones proposed for West Seattle Junction, where she lives. Dense neighborhoods better support small businesses and community events such as block parties, she said.

The council members already have agreed to remove from the plan blocks in Mount Baker and Ravenna-Cowen Park that are part of recently designated historic districts. They also have agreed to express an intent to try to claw back the upzones in the event that a lawsuit nixes the affordable-housing requirements.

Meanwhile, small-business owners and their supporters have been pleading with the council to remove University Way Northeast from the plan, saying upzones on the quirky strip known at The Ave would lead to displacement.

There also could be debate Monday about legislation proposed last week by Councilmember Lisa Herbold. It would require developers who raze relatively inexpensive apartments in certain neighborhoods to engage in mitigation.

The legislation would apply in neighborhoods far from downtown and at risk for displacement, such as Bitter Lake, Rainier Beach and South Park.

Developers demolishing inexpensive apartments would need to replace those homes by including rent-restricted units in their projects or by paying into the city’s affordable-housing fund above what they would otherwise pay under the upzones plan.

The upzones plan would require developers to devote 5 percent to 11 percent of their projects to affordable apartments or pay $5 to $32.75 per square foot in fees. It was initially proposed in 2015, under then-Mayor Ed Murray.

Mandatory Housing Affordability upzones already have occurred in the University District (except for The Ave), downtown, Lower Queen Anne, the Chinatown International District and parts of the Central District.