3368 Washington St. Jamaica Plain/Image courtesy of RODE Architects

Boston city councilors supported elimination of on-site parking requirements for developers of 100 percent affordable housing projects, in a reform that sponsors predict will eliminate a common source of legal challenges.

District 8 Councilor Kenzie Bok said opponents “weaponize parking minimums” to force concessions or block projects that require zoning variances for insufficient parking ratios, in filing the zoning amendment last spring along with Council President Pro Tem Matthew O’Malley earlier this year. The change will apply to developments that include at least 60 percent income-restricted units.

“We know that every unit lost due to delay or the cost of unnecessary, mandated parking is a lost housing opportunity for someone who badly needs it,” Bok said in a statement following Wednesday’s unanimous vote.

The changes will take effect following final approval by the Boston Planning & Development Agency and the Boston Zoning Commission.

Councilors also noted that minimum parking requirements make it harder for developers to complete financing for projects, with average costs of $50,000 per space.

The issue of minimum parking ratios came to the forefront this year after lawsuits challenging a 202-unit affordable project at 3368 Washington St. in Jamaica Plain and a 38-unit project at 3377 Washington St.