California State and County ADU Resources
Understanding California’s state and county regulations is crucial for successful ADU construction. We ensure your project complies with all local requirements.
California State ADU Resources
- California Department of Housing and Community Development (HCD) – Accessory Dwelling Units – The official state resource for ADU regulations, laws, and guidance. Essential for understanding the legal framework for ADU construction in California.
- Accessory Dwelling Unit Handbook (PDF) – Comprehensive guide to California ADU laws updated January 2025. This authoritative handbook covers all aspects of ADU regulations and implementation.
- Maxable – California ADU Regulations Guide 2024 – Detailed breakdown of ADU regulations including sizes, setbacks, heights, and parking requirements. Presented in an easy-to-understand format for homeowners.
- New ADU Laws & Regulations in California 2025 – Guide to the latest ADU laws taking effect in 2025, including Assembly Bill 434 requiring pre-approved ADU plans.
- Governor Newsom Signs Three New Accessory Dwelling Unit Bills – Analysis of recent ADU legislation including AB 2533, SB 1211, and SB 1077, with explanations of how these laws affect homeowners.
California ADU Financing Programs & Incentives
- CalHFA ADU Grant Program – Information about California’s ADU grant program offering up to $40,000 for pre-development costs. Learn about eligibility requirements and application processes.
- CalHFA ADU Income Limits (PDF) – Official income eligibility requirements for the CalHFA ADU grant program by county. Essential for determining if you qualify for state funding.
- CCEDA ADU Program – Assistance applying for the CalHFA ADU grant and financing options for ADU construction. Offers support for both cash-funded and loan-funded ADU projects.
- ADU Financing Guide – Loans, Grants & Incentives in California – Comprehensive guide to ADU financing options in California, including conventional loans, home equity options, and specialized ADU financing programs.
ADU Design & Construction Resources
- Building an ADU – Resource Center – Comprehensive resource for ADU design principles, construction guides, and free resources packet. Includes photo galleries and practical advice for ADU builders.
- How to Build an ADU in the Bay Area: Complete Step-by-Step Guide – Bay Area-specific guide to ADU construction with local considerations and requirements.
- The Bay Area Guide To Building An ADU – Navigation guide for Bay Area ADU regulations and permitting processes. Helps homeowners understand local requirements and procedures.
- Alameda County ADU Resource Center – Resources specific to building ADUs in Alameda County, including local regulations, design guidelines, and permitting information.
- Design an ADU that meets City codes – SF.gov – San Francisco-specific guidance for ADU design and code compliance. Essential for San Francisco homeowners planning an ADU.
- Napa Sonoma ADU Resource Center – Resources for building ADUs in Napa and Sonoma counties, including local regulations and design considerations.
Pre-Approved ADU Plans & Templates
- San Diego Housing Commission ADU Plan Templates – Four sets of pre-approved ADU architectural plans available to the public, ranging from studios to three-bedroom units with customizable options.
- California Assembly Bill 434 – Information about the requirement for all California cities to have pre-approved ADU plans by January 1, 2025, making it easier for homeowners to build ADUs.
ADU Cost Estimation & Financial Planning
- Calculating Costs – Building an ADU – Guide to estimating ADU construction costs, including breakdowns of expenses and budgeting advice for homeowners.
- Saving Money with a Garage ADU – Cost-saving strategies for garage conversion ADUs, highlighting the financial benefits of this approach to ADU construction.
Additional ADU Resources
- California State Fire Marshal ADU Information (PDF) – Information bulletin regarding sprinkler system requirements for ADUs, an important safety consideration for ADU construction.
- ADU Guidance Memo for Coastal Cities and Counties – Guidance for ADUs in Coastal Commission areas, addressing the specific requirements and considerations for coastal properties.
- California Energy Commission Updates for ADUs – Energy code requirements for ADU construction, including solar panel requirements and energy efficiency standards.
- ADU Photo Gallery – Building an ADU – Visual examples of ADU designs and construction, showcasing different styles, layouts, and features for inspiration.
Alameda County ADU Resources
- Official Alameda County ADU Regulations & Requirements – Comprehensive guide to Alameda County’s official ADU regulations, permit requirements, and development standards for unincorporated areas.
- Alameda County ADU Resource Center – Complete Guide to Building ADUs – One-stop resource hub for homeowners planning to build an ADU in Alameda County, featuring step-by-step guidance, tools, and expert advice.
- Alameda County ADU Guidebook – Step-by-Step Building Process – Detailed guidebook covering the entire ADU development process from planning to completion, with practical exercises and professional tips.
City ADU Resources
Oakland
- Oakland ADU Regulations & Permit Process Guide – Complete information on Oakland’s ADU regulations, zoning requirements, and streamlined permitting process for homeowners.
- Oakland ADU Ordinance & Development Standards – Official Oakland ADU ordinance detailing size limitations, setback requirements, parking regulations, and design standards.
Berkeley
- Berkeley ADU Planning Guide & FAQ – Essential information for Berkeley homeowners on ADU regulations, permit requirements, and frequently asked questions.
- Berkeley ADU Zoning Regulations & Development Standards – Comprehensive PDF guide to Berkeley’s ADU zoning regulations, including size limits, height restrictions, and design requirements.
Fremont
- Fremont ADU Development Guide & Regulations– Complete resource for Fremont homeowners on ADU regulations, permit process, and development standards.
- Fremont Pre-Approved ADU Plans & Fast-Track Permitting – Gallery of pre-approved ADU designs that qualify for expedited permit processing in Fremont.
Hayward
- Hayward ADU & JADU Regulations Guide – Comprehensive information on Hayward’s regulations for both Accessory Dwelling Units and Junior Accessory Dwelling Units.
- Hayward Pre-Approved ADU Plans & Streamlined Permitting – Collection of pre-approved ADU designs that qualify for expedited permit processing in Hayward.
San Leandro
- San Leandro ADU Development Standards & Permit Guide – Complete resource for San Leandro homeowners on ADU regulations, zoning requirements, and the permit application process.
Alameda
- Alameda ADU Planning & Development Guide – Comprehensive PDF guide to Alameda’s ADU regulations, development standards, and permit requirements.
Dublin
- Dublin ADU Regulations & Development Standards – Complete information on Dublin’s ADU regulations, zoning requirements, and permit application process.
Livermore
- Livermore Pre-Approved ADU Program & Fast-Track Permitting – Gallery of pre-approved ADU designs that qualify for expedited permit processing in Livermore.
- Livermore ADU Development Guide & Resources – Comprehensive information on Livermore’s ADU regulations, development standards, and permit requirements.
Pleasanton
- Pleasanton ADU Regulations & Development Guide – Complete resource for Pleasanton homeowners on ADU regulations, zoning requirements, and permit process.
- Pleasanton ADU & JADU Development Standards – Detailed PDF guide to Pleasanton’s development standards for both ADUs and JADUs.
Union City
- Union City Pre-Approved ADU Program & Expedited Permitting – Gallery of pre-approved ADU designs that qualify for streamlined permit processing in Union City.
- Union City ADU Application Checklist & Requirements – Comprehensive checklist of requirements for ADU permit applications in Union City.
Newark
- Newark ADU Regulations & Development Standards – Complete information on Newark’s ADU regulations, zoning requirements, and permit application process.
Emeryville
- Emeryville ADU Development Guide & Regulations – Comprehensive resource for Emeryville homeowners on ADU regulations, permit process, and development standards.
Albany
- Albany ADU Regulations & Permit Application Guide – Complete information on Albany’s ADU regulations, zoning requirements, and permit application process.
Piedmont
- Piedmont ADU Development Standards & Regulations – Comprehensive guide to Piedmont’s ADU regulations, development standards, and permit requirements.
ADU Financing and Funding Resources
- Oakland ADU Loan Program – Affordable Financing Options – Information on Oakland’s loan program designed specifically for homeowners building ADUs.
- Alameda County ADU Financing Guide & Budget Planning – Comprehensive resource on financing options, budget planning, and cost considerations for ADU projects in Alameda County.
ADU Design and Construction Resources
- Alameda County ADU Design Guide & Best Practices – Expert design guidance, timeline estimates, and best practices for planning your ADU project in Alameda County.
- ADU Design FAQ & Professional Advice – Answers to frequently asked questions about ADU design, including finding architects and navigating the design review process.
- Alameda County ADU Construction Guide & Builder Resources – Comprehensive information on the construction phase of ADU projects, including finding contractors and managing the building process.
Pre-Approved ADU Plans
- Fremont Pre-Approved ADU Plans & Fast-Track Permitting – Gallery of pre-approved ADU designs that qualify for expedited permit processing in Fremont.
- Hayward Pre-Approved ADU Plans & Streamlined Permitting – Collection of pre-approved ADU designs that qualify for expedited permit processing in Hayward.
- Livermore Pre-Approved ADU Program & Fast-Track Permitting – Gallery of pre-approved ADU designs that qualify for expedited permit processing in Livermore.
- Union City Pre-Approved ADU Program & Expedited Permitting – Gallery of pre-approved ADU designs that qualify for streamlined permit processing in Union City.
ADU Educational Resources
- Alameda County ADU 101 – Beginner’s Guide to ADU Development – Introductory guide to ADU development for homeowners just starting to explore ADU options in Alameda County.
- Alameda County ADU Guidebook – Comprehensive Development Manual – Complete guidebook covering every aspect of ADU development from initial planning to final construction and rental.
Santa Clara County ADU Resources
- Santa Clara County ADU Regulations & Permit Process Guide – Complete guide to ADU regulations, permit requirements, and application process for unincorporated Santa Clara County areas.
- Free Pre-Approved ADU Plans for Santa Clara County Residents – Access free, ready-to-use ADU plans with expedited permitting to save time and money on your accessory dwelling unit project.
- Santa Clara County ADU Center: Comprehensive Resource Hub – One-stop resource center for ADU development throughout Santa Clara County with tools, guides, and local regulations.
- ADU Design Guide: Planning Your Accessory Dwelling Unit – Expert guidance on designing functional, compliant, and beautiful ADUs in Santa Clara County.
- Santa Clara County Pre-Approved ADU Plans Directory – Comprehensive directory of pre-approved ADU plans across all Santa Clara County jurisdictions.
City ADU Resources
San Jose
- San Jose ADU Development Guide: Regulations, Permits & Requirements – Comprehensive resource for building an ADU in San Jose with current regulations, permit processes, and development standards.
- San Jose Pre-Approved ADU Plans & Vendors for Fast-Track Permitting – Explore San Jose’s extensive collection of pre-approved ADU designs with same-day permit potential from qualified vendors.
Sunnyvale
- Sunnyvale ADU Zoning Code & Development Standards – Official municipal code detailing zoning requirements, size limitations, and development standards for ADUs in Sunnyvale.
- Sunnyvale ADU Permit Application & Processing Center – One-stop resource for submitting and processing ADU permits in Sunnyvale with staff assistance.
Santa Clara
- Santa Clara City ADU Regulations & Zoning Requirements Guide – Comprehensive information on ADU development standards, permit processes, and zoning requirements in Santa Clara city.
- Santa Clara City Pre-Approved ADU Plans for Streamlined Permitting – Access pre-approved ADU designs to accelerate your permit process and reduce costs in Santa Clara city.
Mountain View
- Mountain View ADU Development Guide: Regulations & Permit Process – Complete resource for ADU development in Mountain View with current regulations, permit requirements, and development standards.
Palo Alto
- Palo Alto ADU & JADU Handbook: Complete Development Guide – Comprehensive handbook covering all aspects of ADU and Junior ADU development in Palo Alto.
- Palo Alto ADU Municipal Code & Zoning Requirements – Official regulations governing ADU development, size limitations, and zoning requirements in Palo Alto.
Cupertino
- Cupertino ADU Development Guide: Regulations & Requirements – Complete resource for building an ADU in Cupertino with current regulations and development standards.
- Cupertino Pre-Approved ADU Plans for Fast-Track Permitting – Access pre-approved ADU designs for expedited permit processing and reduced costs in Cupertino.
Campbell
- Campbell ADU & JADU Municipal Code & Development Standards – Official regulations governing ADU and Junior ADU development in Campbell with detailed standards.
- Campbell Planning Division: ADU Permit Process & Resources – Information on planning, permitting, and development resources for ADU projects in Campbell.
Los Gatos
- Los Gatos ADU Development Guide: Regulations & Permit Process – Comprehensive resource for ADU development in Los Gatos with current regulations and permit requirements.
Milpitas
- Milpitas ADU Development Guide: Regulations & Requirements – Complete resource for building an ADU in Milpitas with current regulations and development standards.
- Milpitas ADU Municipal Code & Zoning Requirements – Official regulations governing ADU development, size limitations, and zoning requirements in Milpitas.
Saratoga
- Saratoga ADU Development Guide: Regulations & Requirements – Comprehensive information on ADU development standards, permit processes, and zoning requirements in Saratoga.
- Saratoga Pre-Approved ADU Plans Gallery for Streamlined Permitting – Access pre-approved ADU designs to accelerate your permit process and reduce costs in Saratoga.
ADU Financing and Funding Resources
- Housing Trust Silicon Valley: ADU Financing for Santa Clara County Homeowners – Local financing program specifically designed for Santa Clara County homeowners building ADUs.
- Mission City Federal Credit Union: Specialized ADU Financing Options – Local credit union offering customized financing solutions for ADU construction in Santa Clara County.
- ADU Home Equity Loans & HELOCs: Financing Your Accessory Dwelling Unit – Guide to using home equity to finance your ADU project with competitive rates.
- ADU Construction Loans & Renovation Financing Options – Comprehensive guide to construction loans and renovation financing specifically for ADU projects.
Pre-Approved ADU Plans
- Santa Clara County Free Pre-Approved ADU Plans: 800-1,200 sq. ft. Options – Access free, ready-to-use ADU plans with expedited permitting for county residents.
- San Jose Pre-Approved ADU Vendor Directory: 330-1,200 sq. ft. Options – Extensive directory of pre-approved ADU vendors and designs for San Jose residents.
- Cupertino Pre-Approved ADU Plans for Fast-Track Permitting – Access pre-approved ADU designs for expedited permit processing in Cupertino.
ADU Cost Estimation Tools
- Santa Clara County ADU Cost Calculator: Estimate Your Project Budget – Interactive tool to estimate construction costs and return on investment for your ADU project.
ADU Construction Guidelines
- San Jose ADU Universal Checklist: Comprehensive Building Guide – Complete checklist covering all aspects of ADU construction in San Jose.
- San Jose ADU Fire Safety Requirements & Compliance Guide – Detailed guide to fire safety requirements for ADU construction in San Jose.
- San Jose ADU Permit Process: Step-by-Step Application Guide – Comprehensive guide to navigating the ADU permit application process in San Jose.
San Mateo County ADU Resources
- San Mateo County Official ADU Ordinance & Development Standards – Complete guide to legal requirements, zoning regulations, and development standards for building Accessory Dwelling Units in unincorporated San Mateo County areas.
- San Mateo County ADU Resource Center: Complete Homeowner’s Guide – One-stop resource hub providing step-by-step guidance for planning, designing, permitting, and building your ADU in San Mateo County, with expert advice and local requirements.
- San Mateo County Comprehensive ADU Guidebook: Planning to Completion – Detailed guidebook covering all aspects of ADU development including regulations, financing options, design considerations, and construction requirements.
- San Mateo County ADU Amnesty Program for Unpermitted Units – Official program offering low-cost, penalty-free pathway to legalize and improve existing unpermitted accessory dwelling units to meet health and safety standards.
- San Mateo County ADU Permitting Guide: Timeline & Requirements – Comprehensive guide to the ADU permitting process in San Mateo County, including application requirements, review process, and typical timeline expectations.
City ADU Resources
Redwood City
- Redwood City ADU Ordinance & Pre-Approved Plans – Complete guide to Redwood City’s ADU regulations, including development standards, setback requirements, and pre-approved plans to streamline your project.
- Redwood City ADU Permit Application & Completeness Checklist – Detailed information about applying for ADU permits in Redwood City, including the ADU Completeness Checklist and Building Permit application requirements.
San Mateo
- City of San Mateo ADU & JADU Regulations: Complete Guide – Comprehensive information about Accessory Dwelling Unit and Junior ADU regulations in San Mateo City, including zoning requirements, size limitations, and approval process.
- City of San Mateo Online Permit Center: ADU Applications – Secure online portal for submitting ADU building permit and planning applications in the City of San Mateo, with tracking and status updates.
Daly City
- Daly City ADU Regulations & Building Requirements – Official guide to Daly City’s ADU regulations, including development standards, parking requirements, and application process for homeowners.
South San Francisco
- South San Francisco ADU Regulations & Pre-Approved Plans – Detailed information about South San Francisco’s ADU regulations, including development standards, pre-approved plans, and streamlined approval process.
- South San Francisco ADU Permit Applications & Requirements – Complete information about the two applications required for ADUs in South San Francisco: Building Permit application and Deed Restriction application.
Menlo Park
- Menlo Park ADU & JADU Development Standards & Requirements – Complete guide to Menlo Park’s regulations for Accessory Dwelling Units and Junior ADUs, including size limitations, design standards, and approval process.
San Carlos
- San Carlos ADU Building Guide & Pre-Approved Plans – Comprehensive information about San Carlos ADU regulations, including development standards, pre-approved plans, and expedited review process.
Belmont
- Belmont ADU Development Standards & Zoning Requirements – Official guide to Belmont’s ADU regulations, including zoning requirements, size limitations, and approval process for homeowners.
Foster City
- Foster City ADU Regulations & Permit Process Guide – Detailed information about Foster City’s ADU regulations, including development standards, application requirements, and approval process.
ADU Financing Programs and Resources
- HEART of San Mateo County: Affordable Housing & ADU Programs – Housing Endowment and Regional Trust programs supporting affordable housing initiatives, including resources and assistance for ADU development in San Mateo County.
- San Mateo County ADU Financing Guide: Loans, Grants & Options – Complete guide to financing options for ADU projects in San Mateo County, including home equity loans, construction loans, and specialized ADU financing programs.
- ADU 101 Online Workshop: Financing & Development Guide – Free educational workshop covering all aspects of ADU development, including financing options, construction considerations, and regulatory requirements.
Pre-Approved ADU Plans
- San Mateo County ADU Construction Guide: Building Your Unit – Comprehensive guide to the construction phase of ADU development, including contractor selection, construction timeline, and quality control measures.
- Second Unit Resource Center: Complete ADU Development Guide – Additional educational resources for homeowners interested in building ADUs in San Mateo County, including jurisdiction-specific information.
ADU Cost Estimation Tools
- San Mateo County ADU Cost & Rental Income Calculator – Free interactive tool to estimate construction costs, potential rental income, and return on investment for your Accessory Dwelling Unit project in San Mateo County.
- ADU Permit Fee Guide: Costs & Expenses Explained – Detailed overview of the various fees charged for ADU permits in San Mateo County, including both fixed fees and project-specific fees from local government, state, and other agencies.
- San Mateo County Service Fee Schedules for ADU Development – Current Planning, Building, and Fire service fee schedules for ADU development in San Mateo County, updated for 2025.
ADU Permit Resources
- San Mateo County ADU Building Permit Process: Complete Guide – Official step-by-step guide to obtaining building permits for ADUs in unincorporated San Mateo County, including application requirements and review timeframes.
- San Mateo County Online Permit Center: ADU Application Portal – Official online portal for submitting ADU building permit applications in unincorporated San Mateo County areas, with tracking and status updates.
- ADU Permit Application Requirements: Complete Document Checklist – Comprehensive list of required documents for ADU permit applications, including site plans, architectural plans, structural plans, and other essential materials.
- San Mateo County Coastal Zone Boundary Map for ADU Development – Official map to determine if your property requires additional permits from the California Coastal Commission for ADU construction.
ADU Inspection Resources
- San Mateo County ADU Inspection Scheduling & Requirements – Complete guide to scheduling and preparing for inspections during ADU construction in San Mateo County, including the new Automated Inspection Scheduling System.
- ADU Conversion Inspection Requirements & Process Guide – Detailed information about inspection requirements for conversion ADUs or ADUs within existing structures, including required walkthroughs during the application process.
ADU Educational Resources
- Frequently Asked Questions about ADU Permits & Process – Expert answers to common questions about ADU permits, costs, water and sewer considerations, and potential compliance issues for San Mateo County homeowners.
- ADU Planning Exercises & Worksheets for Homeowners – Practical worksheets and exercises to help homeowners assess their options, develop a budget, and create a comprehensive plan for their ADU project.
ADU Rental Resources
- San Mateo County ADU Rental Guide: Landlord Requirements – Complete information about renting out your ADU in San Mateo County, including legal requirements, tenant screening, lease agreements, and best practices for property management.
- ADU Income & Tax Considerations: Financial Planning Guide – Comprehensive information about the financial implications of building and renting an ADU, including tax considerations, rental income reporting, and property value impacts.
Contra Costa County ADU Resources
- Contra Costa County Official ADU Information Portal – Official county information on ADU requirements and processes
- Contra Costa County Pre-Approved ADU Plans – County-approved ADU designs to streamline the permit process
- Contra Costa County ADU Zoning Ordinance – Official ADU regulations and definitions
City ADU Resources
Concord
- Concord ADU Information Portal – Official city information on ADU requirements
- Concord ADU Development Standards Guide – Comprehensive guide to ADU development standards
- Concord ADU Zoning Regulations – Detailed zoning regulations for ADUs
Antioch
- Antioch ADU Information Portal – Official city information on ADUs
- Antioch ADU Application Process Guide – Step-by-step application process
- Antioch Pre-Approved ADU Plans – City-approved designs to streamline permitting
Richmond
- Richmond ADU Information Portal – Official city information on ADUs
- Richmond ADU Ordinance & Regulations – Official ADU regulations
- Richmond ADU Application Requirements – Required documents for ADU applications
San Ramon
- San Ramon ADU Permit Requirements – Official City Document
- San Ramon ADU Development Standards – 2024 Official ADU Development standards
- San Ramon Building Division Contact – For ADU permit inquiries
Walnut Creek
- Walnut Creek ADU & JADU Information Portal – Official city information on ADUs and JADUs
- Walnut Creek Pre-Reviewed ADU Plans – City-approved designs in various architectural styles
- Walnut Creek ADU Rebate Program – Program to save time and money on ADU projects
Brentwood
- Brentwood ADU Information Portal – Official city information on ADUs
- Brentwood ADU Ordinance & Regulations – Official ADU regulations
- Brentwood ADU Permit Application – Required for ADU construction
- Brentwood ADU & JADU Deed Restrictions – Required legal documents
Martinez
- Martinez ADU & JADU Information Portal – Comprehensive one-stop-shop for ADU information
- Martinez ADU Development Standards – Detailed development standards for ADUs
- Martinez ADU Bonus Program – Program for deed-restricted affordable units
- Martinez Building Division Contact – (925) 372-3596 for inspections and inquiries
Pittsburg
- Pittsburg ADU Information Portal – Official city information on ADUs
- Pittsburg ADU Development Guidebook – Comprehensive guide (November 2024)
- Pittsburg Pre-Approved ADU Plans – Pre-approved designs with elevation and floor plans
- Pittsburg Online ADU Permit Portal – ACCELA system for permit applications
- Pittsburg ADU Planning Contact – Kelsey Gunter, Associate Planner, (925) 252-4824
ADU Educational Resources
- Contra Costa County ADU Educational Workshops – Information sessions on ADU development
- Contra Costa County ADU Cost & Rental Income Calculator – Tool to estimate costs and potential rental income
- How-to-ADU YouTube Channel for California Homeowners – Video tutorials on ADU development
