ADU Builder in San Rafael

We serve Northern California across three regions: the San Francisco Bay Area, Greater Sacramento, and the Central Valley. Our published guides cover 14 counties and 88 cities. Our Castro Valley and Sacramento offices support local estimating, permit coordination, and project planning across these regions.

Financing may be available for eligible projects with approved credit. Available terms depend on lender approval, project scope, and current programs. Your project manager can review the options that apply before work begins. We also accept checks, ACH, and major credit cards.

Yes. Hamilton Exteriors holds CSLB License #1078806, active general liability coverage, and the required contractor bond. We also hold GAF Master Elite and James Hardie Elite Preferred credentials. We can provide current proof of coverage before work begins.

Permit requirements depend on the project scope and local jurisdiction. Hamilton Exteriors coordinates required applications, plan documents, corrections, and inspections. Permit fees and allowances appear in the proposal before construction begins.

### Architect-Led Design-Build Most ADU contractors in the Bay Area are tradesmen-only. Hamilton Exteriors is different. Our projects are led by Alexander Hamilton Li, a licensed architect and general contractor (CSLB #1078806). This means design and construction decisions are made by the same team, eliminating the gaps that occur when architects and builders work independently. The result: fewer change orders, a finished product that matches what was designed, and a smoother overall process.

The cost of a San Rafael ADU depends on whether you convert existing space or build a detached unit. Foundation work, grading, utility routes, finishes, and the applicable fees affect the estimate. Ask for a written scope that separates design, construction, site work, and utility costs. Confirm what the total includes before comparing proposals.

From permit approval, most detached ADUs complete in 4 to 6 months. Garage conversions are faster at 2 to 4 months since the shell already exists. The permitting phase adds 2 to 4 months depending on plan review backlog. Total timeline from design to move-in is typically 8 to 12 months. Your project manager provides a detailed construction schedule at contract signing with weekly milestone updates.

Yes. All ADUs in California require a building permit. San Rafael's Building Division handles ADU permit applications. California law requires cities to approve or deny ADU permits within 60 days. Hamilton Exteriors handles the full permitting process — architectural plans, structural engineering, Title 24 energy compliance calculations, plan check submittal, and inspection coordination throughout construction.

An ADU needs a review of your San Rafael property and the type of unit proposed. Check the usable space, setbacks, utilities, fire access, and applicable local requirements. Existing-structure conversions and new detached units can follow different rules. Confirm the project with the city before assuming the lot qualifies.