Mill Valley ADU Developer — Garage, Home, and Backyard Conversions.
About SYMBiHOM in Mill Valley
Mill Valley homeowners are in one of Marin County's most sought-after communities — and one with its own active ADU pre-approval program. Whether you're converting a garage, repurposing interior home space, or adding a backyard unit, the permitting path is established. SYMBiHOM is a CA HCD approved ADU Design-Build Developer serving Mill Valley homeowners.
Our Credentials in Mill Valley
SYMBiHOM holds CA HCD approval and is actively pursuing pre-approved vendor status with the City of Mill Valley. Mill Valley operates its own Pre-Approval program for detached ADUs, with Master Plan permits valid until the next building code cycle. We are also the only pre-approved garage conversion builder on the City of San José's official vendor list.
Permitting in Mill Valley
Mill Valley's pre-approval program covers detached ADUs. No modifications to pre-approved plans are permitted except mirroring floor plans. Properties in flood hazard areas may require flood-resistant design elements. We assess your property's eligibility as part of your free feasibility review — before you spend anything.
Animation of Symbihom’s Garage Conversion
What We Build
• Attached or detached garage conversion — studio, 1BR, or 2BR, 300–850 sq. ft.
• Junior ADU (JADU) — attached garage, up to 500 sq. ft.
• Home conversion — convert underutilized interior space into a fully permitted ADU
• Backyard ADU — new detached unit on your existing lot
• State-approved factory-built panel system
• Fully customizable finishes — cabinetry, flooring, fixtures
• ADA-accessible design available
• Sub-metered electricity and water available
Timeline:
Typical build: 4–6 weeks after permits are issued. Designs are customizable across garage conversions, home conversions, and backyard ADUs.
Is Your Property Eligible?
The lot must be zoned residential with an existing single-family home or duplex, and must not be located in a geohazard, landslide, flood zone, or Wildland-Urban Interface area. The property must not have an open Code Enforcement violation.
Not sure if your property qualifies? Fill out the form below. We check zoning and flag any issues before you spend anything.