Marin County, CA Zoning Overlays & Bonuses: Density Bonus Law (2026)

020 (Density Bonus and Other Incentives Pursuant to State Law) sets Marin County's standards and procedures for granting density bonuses, incentives, concessions, waivers, and reduced parking ratios required by Government Code Sections 65915-65918. Nine project types qualify, including 5% very-low-income or 10% low-income unit developments, developments where 80% of units serve lower-income households, senior housing of 35+ units, student housing with 20% of beds reserved for lower-income students, and projects with childcare facilities or land donations. A qualifying project starts at a 20% density bonus and the bonus increases on a sliding scale as the affordable share grows, per Table 3-5a, reaching up to an 80% bonus for a project where at least 80% of units serve lower-income households; that top-tier project also gets a height increase of up to three stories or 33 feet, and an exemption from maximum density controls, if it sits within a half mile of a major transit stop.

Table 3-5c ties the number of development-standard incentives or concessions available, from one up to five, to the affordability tier reached, and the applicant may also request an unlimited number of waivers for any standard, including height, setback, coverage, floor area, or parking, that would physically preclude building at the bonus density. The request must be submitted with the project's affordable housing plan and supported by a written financial statement demonstrating the incentive produces an identifiable, actual cost reduction.