Boston's booming lab market has added pressure to the area's tight housing market, and one development featuring both uses in Allston is looking to dramatically increase its percentage of income-restricted homes.

The developers behind the 119 Braintree St. project had said in 2020 they planned to set aside 20% of the units as affordable, but an updated development filing last week shows they now plan to have income restrictions on around 85% of the project's 86 apartments, the Boston Business Journal first reported.

The joint venture of Braintree Street Realty LLC and Bracken Development brought on affordable housing developer Pennrose last year to help increase that percentage, and it plans to use a mix of state funding programs, federal tax credits and private equity investments, the developers told BBJ.

Of the project's 86 units, 43 are expected to be income-restricted at the 80% area median income level, while another 30 units would be at the 120% AMI level, according to last week's filing. According to BBJ, 80% of AMI equates to $96,650 for a four-person household, while 120% of AMI equates to $144,950 for a four-person household.

That 120% AMI range is often considered workforce housing and provides options for middle-income people who may not be able to afford the city's increasingly expensive market-rate rents, but who don't qualify for more deeply subsidized housing. Boston apartment rents last quarter increased by 11% year-over-year, according to Colliers.

The six-story multifamily building is part of a larger mixed-use development that is also planned to include 373K SF of office or lab space and 12K SF of retail, according to the filing with the Boston Planning & Development Agency.

The new buildings would replace a seven-story office building that was constructed around 1900, plus a one-story fitness center building. The site is less than a half-mile from the Boston Landing mixed-use development and the MBTA commuter rail station with the same name.

The area around Boston Landing has become a growing target for life sciences development over the last two years. In July, life sciences developer IQHQ acquired the site at 155 North Beacon St. for $50M. In March 2021, Lendlease and Ivanhoé Cambridge paid $67M for the site at 60 Guest St., where they plan a 320K SF lab building. And in October 2020, Berkeley Investments filed plans for 584K SF of lab-ready office space, plus multifamily and retail, at 176 Lincoln St.