When it's required
The Inclusionary Zoning Policy applies to:
- All new multi-unit housing, including apartments, condominiums and conversions
- Any subdivision with a proposed development of one or more new units
- Any subdivision creating one or more new lots
The Inclusionary requirements vary by project type with Rental Housing and Homeownership Housing having different affordability targets
Unit/lot calculation
Projects must dedicate 20% of the project as affordable housing. In some instances, this calculation results in a fractional unit (not a whole number). The developer can choose to round up and provide an additional unit of affordable housing, or pay a proportionate in-lieu fee.
Applicants seeking a waiver and requesting to pay an in-lieu fee rather than fulfill the County’s inclusionary requirements should consult Marin County Code Chapter 22.22.060, “Waivers,” to understand the conditions under which such a request might be granted.
Payment of any applicable affordable housing fees are required prior to filing of maps or issuance of any building permits, as determined in the approved Affordable Housing Plan.
The 2025-26 in-lieu fee is $406,051.00.
Rental projects
Rental housing projects may choose from two income options. In each option, 20% of the project must be dedicated as affordable housing.
| Project Size | Option 1 (20% of Total) | Option 2 (20% of Total) |
|---|---|---|
| 10 units or less | 10% Very Low-Income Units and 10% In Lieu Fee | 15% Low-Income Units and 5% In Lieu Fee |
| 11 to 29 units | 10% Very Low-Income Units and 10% Moderate Income Units | 15% Low-Income Units and 5% Moderate Income Units |
| 30 or more units | 15% Very Low-Income Units; and 5% Moderate Income Units or 5% in Lieu fee | 10% Very Low-Income Units, 5% Low Income Units, and 5% Moderate-Income Units |
Ownership projects
Ownership housing projects must dedicate 20% of the project as affordable housing.
| Project Size | Policy (20% of Total) |
|---|---|
| 4 units or less | All Middle Income Units |
| 5 to 29 units | 5% Low-income Units, 5% Moderate-Income Units, 10% Middle Income Units |
| 30 or more units | 5% Low-income Units, 10% Moderate-Income Units, 5% Middle Income Units |
The income ranges and allowable rent levels or sales prices are defined in the table below. The Marin Housing Authority manages the County’s portfolio of below-market-rate affordable homeownership units. Contact Jeff Kelly for questions about how the sale price of inclusionary units is set and to learn more about how monthly rents are calculated for affordable rental units.
| Income Category | Income Range | Rent Level | Sales Price Level |
|---|---|---|---|
| Very Low Income | 30-50% AMI | 50% AMI | N/A |
| Low Income | 50-80% AMI | 65% AMI | 65% AMI |
| Moderate Income | 80-120% AMI | 100% AMI | 100% AMI |
| Middle-Income | 120-150% AMI | N/A | 135% AMI |
Calculator
You can use our Inclusionary and In-Lieu Fee calculator to determine fees based on your specific project.