SB9 Subdivision Experts
SB 9 Lot Split & Subdivision Services in California
Unlock the full potential of your land. We help California homeowners navigate Senate Bill 9 to split their lots, build additional units, and significantly increase property value with professional design and engineering.
By the Numbers
California Trusted Architectural & Structural Engineering
Monthly Active Projects
Projects Delivered
Permit Approval Rate
Professional Team Members
Trust & Collaboration
Turn One Property Into Two. Or Four.
Senate Bill 9 allows eligible homeowners to split their single-family lot into two separate parcels and build up to two units on each.Navigating the eligibility requirements and city ordinances is complex. Our team provides the feasibility analysis, architectural design, and engineering required to execute a profitable SB9 project.
All featured projects are real, city-approved plans.
Why You Need This
Why Consider an SB9 Lot Split?
Understanding the risks of going it alone vs. the rewards of professional execution.
Risks of Incorrect Filing
- Most applicants are rejected for incomplete site plansCity planners require precise setbacks and easements on the first try.
- Utility access & setbacks are misunderstood by 80% of homeownersIncorrect utility mapping can kill a project before it starts.
- Costly delays from non-compliant map submissionsEvery resubmission adds weeks or months to your timeline.
Benefits of SB9
- Legally increase property value overnightLot splits allow you to create a new APN, unlocking equity instantly.
- Create a new separate buildable lot to sellSell the new lot to a developer or private buyer for immediate profit.
- Add rental units for long-term passive incomeBuild a duplex or ADUs to generate significant monthly cash flow.
Why Choose Cecilia Home
- In-house SB9 Engineering & Survey TeamWe have 20+ specialists dedicated to subdivision and land planning.
- Direct Communication with City PlannersWe handle all negotiations and corrections directly with the jurisdiction.
- Fast Turnaround for FeasibilityGet a clear "Go/No-Go" answer and Tentative Map strategy quickly.
- Proven Track RecordWe have successfully guided numerous homeowners through the SB9 process.
Why Choose Us
Why Homeowners Choose Cecilia Home
We’re not just another design firm — we’re the most-reviewed architecture firm on Thumbtack, completing 2–3 projects every week across California.
#1 RANKED ON THUMBTACK
The highest-rated and most-reviewed architecture firm on Thumbtack in California — 500+ verified reviews and a 4.9★ rating from real homeowners.
FIXED-PRICE, ALWAYS
We give you the complete, all-inclusive price before you commit — no lowball estimates, no change-order surprises. Just one honest number you can plan around.
DEEP SPECIALIZATION
We complete 2–3 projects of the same type every single week. That’s more hands-on experience in one month than most firms accumulate in a year.
TRUSTED CONTRACTOR NETWORK
We connect you with vetted, licensed contractors we work with repeatedly — no vetting required on your end, no coordination gaps between design and construction.
COMPLETE QUOTE UPFRONT
Share your project details and we respond within 1 business day with a complete, all-inclusive quote. No ‘I’ll need to come see it first,’ no hidden fees added later.
CALIFORNIA PERMIT EXPERTS
Licensed architects and structural engineers with deep knowledge of California codes, city-specific requirements, and a 99% permit approval rate across the state.
SB 9 Services
Complete SB 9 Lot Split & Housing Solutions
From feasibility and lot split layouts to two-unit design and permit approvals, we deliver complete SB 9 solutions for California homeowners.
SB 9 Urban Lot Split
Conceptual and permit-ready layouts that split one property into two legal parcels, including new lot lines, access, and basic development potential for each lot.
Two-Unit SB 9 Development
Site planning and building design for SB 9 two-unit projects—such as an existing home plus a new SB 9 unit—coordinated with setbacks, parking, and open-space requirements.
Lot Split with Two New Homes
Architectural and structural plans for creating two separate homes on newly split SB 9 parcels, including massing studies, elevations, and engineering for each unit.
SB 9 Setback & Compliance Study
Detailed analysis of setbacks, easements, utilities, and zoning limits, with buildable area diagrams that show exactly where SB 9 units can be placed on your property.
Our Process
Our Process
Our process is designed to be transparent and efficient, delivering a complete one-stop service from design to final permit approval.
Guidance for your project
- 01Free Consultation & Fixed-Price Quote
Free Consultation & Fixed-Price Quote
Share your project details and get a complete, fixed-price quote — full scope, full cost, no vague estimates.
Step 120% - 02On-Site Assessment
On-Site Assessment
Precise measurements and site evaluation for accurate project planning.
Step 240% - 03Design Development
Design Development
Creating detailed plans and visualizations to bring your vision alive.
Step 360% - 04Permit Acquisition
Permit Acquisition
Navigating complex approval processes to ensure code-compliant construction.
Step 480% - 05Construction Support
Construction Support
Ongoing guidance and contractor coordination throughout the building process.
Step 5100%
Client Testimonials
Trusted by California Homeowners
Ranked #1 on Thumbtack based on verified reviews from homeowners who relied on our architectural and structural engineering services.
Cecilia Home designed our complete home renovation, explained everything clearly, and delivered detailed plans. Honest, professional, and fairly priced—our HOA now knows exactly how to proceed.
View Verified ReviewTrudy M.
Home Remodeling
Mason delivered exactly what I needed—professional, responsive, and great value. Clear communication throughout the process. I'll rely on him for all future remodeling projects.
View Verified ReviewJoanne D.
Home Remodeling
Mason responded instantly and offered honest guidance on whether my garage conversion would pass city review. Knowledgeable, direct, and trustworthy—I look forward to working with them again.
View Verified ReviewJasper T.
ADU Design
I appreciated their honesty. They explained that my foundation cracks were common in the Bay Area and didn't push unnecessary work. Professional, transparent advice I could trust.
View Verified ReviewArturo S.
Structural Engineering
As a general contractor, I value teams who are responsive and accurate. Cecilia Home delivered clear communication, timely plans, and over-the-counter approval. I highly recommend them.
View Verified ReviewKevin V.
Building Permit Services
Mason gave detailed structural guidance for removing our load-bearing wall, including safety considerations. Quick responses and practical advice that helped us comply with local regulations.
View Verified ReviewJackson B.
Wall Removal
Our Services
Our Range of Services
Comprehensive design and construction solutions for residential and commercial projects, delivered with expertise and attention to detail.
ADU Design
Custom Accessory Dwelling Unit designs that maximize your property value while maintaining aesthetic harmony.
Wall Removal
Remove load-bearing walls to create more space in your home.
Home Addition
Add extra space to your home with a new room or extension.
Home Remodeling
Transform your home with expert kitchen, bathroom, and living room remodeling.
Building Permit Service
Secure your building permits with our 100% approval rate and complete regulatory compliance guidance.
Foundation Inspection
Expert foundation inspection with detailed structural reports to ensure safety and long-term stability.
FAQ
SB 9 Questions
Answers to the most common questions about California's Senate Bill 9 lot split law.
Haven't found what you're looking for?
Eligibility depends on zoning (single-family), setbacks, hazardous zones, historic districts, utilities, and access requirements. We perform a complete feasibility study to determine qualification before starting the project.
Yes. Both the lot split and new units require comprehensive architectural plans, structural engineering, Title 24 compliance, and detailed site planning to meet SB 9 and local city codes.
Timelines vary by city. Feasibility and design typically take 4–8 weeks, while city review ranges from 8–20 weeks depending on caseload and complexity.
Yes. SB 9 allows lot splits and also permits two residential units per parcel, enabling homeowners to create new income-producing units.
Yes. We prepare the application, submit the plans, respond to reviewer comments, coordinate with planning and building departments, and manage the process until final approval.
No. ADUs fall under separate state laws. SB 9 allows lot splits and additional units on newly created parcels. Many homeowners use SB 9 and ADU laws together to maximize property value.
SB 9 Lot Split & Subdivision Services in California
Senate Bill 9 allows eligible homeowners to split their single-family lot into two separate parcels and build up to two units on each.Navigating the eligibility requirements and city ordinances is complex. Our team provides the feasibility analysis, architectural design, and engineering required to execute a profitable SB9 project.