Introduction
Milpitas has established clear and supportive regulations for Accessory Dwelling Units (ADUs) to encourage homeowners to build additional living spaces on their properties. These regulations are designed to ensure safety, aesthetic consistency, and neighborhood compatibility. ADU Specialist Bay Area can assist homeowners in navigating these regulations, ensuring that all construction and design processes meet Milpitas’ requirements, and help expedite the approval and building process.
Essential ADU Rules for Milpitas
What you can build
Maximum size
Up to 1,200 square feet is allowed for detached ADUs.
Side / rear setbacks
A minimum of 4 feet is required.
Two stories
Permitted, with a maximum height of 16 feet.
Building separation
A minimum of 10 feet between structures.
Permitting timeline
Standard
Typically processed within 60 days.
Coastal
N/A as Milpitas is inland.
Zoning Regulations in Milpitas
Milpitas zoning laws are crafted to balance development and community standards. Residential zones R-1, R-2, and R-M typically permit ADUs.
ADU Size Limitations
| Lot Size | Single-Family (Maximum Floor Area Allowed) | Duplex and Multi-Family (Maximum Floor Area Allowed) |
| Under 7000 | 600 sq ft | Not permitted |
| 7000 - 9999 | 750 sq ft | 1 ADU + 350 sq ft per existing unit (up to 900 sq ft max) |
| 10000 - 12999 | 850 sq ft | 1 ADU + 400 sq ft per existing unit (up to 950 sq ft max) |
| 13000 - 19999 | 950 sq ft | 1 ADU + 450 sq ft per existing unit (up to 1000 sq ft max) |
| 20000+ | 1000 sq ft | 1 ADU + 500 sq ft per existing unit (up to 1000 sq ft max) |
ADU Height Limitations
ADUs in Milpitas have a height limit of 16 feet for single-story and 25 feet for two-story units.
Building Coverage
The maximum building coverage for an ADU is 40% of the lot area.
Location
| Property Type | Location Requirement |
| Single-Family Homes | Attached ADUs: Must be located in the rear half of the lot. |
| Detached ADUs: Must be at least 10 feet from the main house. | |
| Junior ADUs (JADUs): Must be within the primary residence. | |
| Duplex and Multifamily | Attached ADUs: Must be in rear or side yards. |
| Detached ADUs: Must be at least 15 feet from other structures. |
Exterior details
ADUs must match the exterior design and color scheme of the primary residence to ensure aesthetic consistency.
Parking
One additional parking space is required for ADUs, but there are exemptions near public transit and car share areas.
Setbacks and buffer zones
Minimum setbacks of 4 feet from side and rear property lines are required for ADUs.
Minimum Lot Area
| Lot Size | Minimum Lot Area for ADU | Description |
| Under 7000 | ADUs not permitted | Smaller lots are unsuitable for ADUs. |
| 7000 - 9999 | 7000 sq ft | Sufficient area for a small ADU. |
| 10000 - 12999 | 10000 sq ft | Suitable for medium-sized ADU. |
| 13000 - 19999 | 13000 sq ft | Adequate space for larger ADUs. |
| 20000+ | No minimum lot area requirement | Large lots offer more flexibility. |
Connection for utilities
All ADUs must have separate utility connections for water, sewer, and electricity, and meet all city standards.
Fire safety
ADUs must comply with local fire codes, including the installation of smoke detectors and fire-resistant materials.
Room specifications
- Sleeping Areas: Must have at least one window and an emergency exit.
- Kitchen: Must include a sink, refrigerator, and cooking facilities.
- Bathroom: Required to have a toilet, sink, and shower or bathtub.
- Storage: Must include built-in storage or closets.
Short-term Rentals and Home Occupations Regulations
Short-term rentals of ADUs are permitted, provided the owner complies with local rental regulations.
Building Codes
ADUs must meet all local building codes, including those for electrical, plumbing, and structural integrity.
Milpitas ADU Permit Guidelines
| Permit Type | Description | Estimated Fee |
| Building Permit | Required for ADU construction. | $2500 - $5000 |
| Electrical Permit | Required for electrical work. | $400 - $700 |
| Plumbing Permit | Required for plumbing installations. | $400 - $700 |
| Mechanical Permit | Required for HVAC systems. | $400 - $700 |
| Grading Permit | Required for land grading. | $300 - $500 |
| Site Development Permit | Required for site planning. | $300 - $500 |
| Zoning Permit | Required for zoning compliance. | $200 - $400 |
Property requirements
Properties must meet zoning and building code requirements to qualify for ADU development in Milpitas.
Parking
ADU developments must provide one off-street parking space per unit, unless exempted.
Front setbacks
A minimum front setback of 20 feet is required for ADU construction.
Side and rear setbacks
A minimum of 4 feet from side and rear property lines is necessary for ADUs.
Open space and rear yards
ADUs must maintain a minimum of 20% open space in the rear yard.
Properties that qualify
To determine your property’s eligibility for ADU development, contact the Milpitas Planning Department.
- Verify that your property is within Milpitas’ jurisdiction.
- Check the specific residential zones that permit ADUs. Common zones in Milpitas include R-1, R-2, and R-M.
- Other General Plan designations that permit ADUs:
- Residential Mixed-Use (RMU): Areas designated for mixed residential and commercial use.
- Transit-Oriented Development (TOD): Zones near public transit hubs.
- Specific Plan areas: Zones with tailored development standards.
Development standards
Single-family
- Attached: Must share a wall with the primary residence.
- Detached: Must be located in the rear yard.
Duplex properties
- Attached: Can be added to the existing structure.
- Detached: Must be placed in the rear or side yard.
Multifamily properties
- Attached: Can be integrated into the existing building.
- Detached: Must be located in the rear yard.
Junior ADUs (JADUs)
JADUs must be within the primary residence and limited to 500 square feet.
Property designations
- Flood Zones: ADUs must comply with all floodplain regulations.
- Geohazard Zones: Additional geotechnical studies may be required.
- Historic Designation: ADUs in historic zones must preserve the architectural character.
- Easements: ADUs cannot be built over easements for utilities or access.
Summary
Milpitas offers a supportive framework for ADU development, balancing community needs with the benefits of increased housing. By adhering to local regulations, homeowners can successfully add ADUs to their properties, providing additional living space and potential rental income. ADU Specialist Bay Area is ready to assist with every step of the process, from initial planning to final construction, ensuring compliance and quality.
FAQ
Verify your property zoning with the Milpitas Planning Department to ensure it qualifies for ADU development.
A minimum of 4 feet from side and rear property lines is required.
Yes, two-story ADUs are permitted with a maximum height of 25 feet.
Yes, multiple permits are required, including building, electrical, and plumbing permits.
Standard permit processing takes about 60 days.
Yes, ADUs can be rented out, including short-term rentals.
Detached ADUs can be up to 1,200 square feet.
Yes, one off-street parking space is required, with some exemptions.
No, ADUs are not permitted on lots under 7,000 square feet.
Yes, ADUs must match the design and color of the primary residence.
Yes, ADUs must have separate utility connections for water, sewer, and electricity.
ADUs must comply with local fire codes, including smoke detectors and fire-resistant materials.
ADUs must include a kitchen, bathroom, sleeping area, and storage.
Yes, the height limit is 16 feet for single-story and 25 feet for two-story ADUs.
It varies by lot size, with larger lots offering more flexibility.
Yes, but the ADU must preserve the architectural character of the district.
