Home Addition Contractor 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.

San Rafael home additions typically cost $200 to $400 per square foot depending on scope and finishes (Hamilton Exteriors 2024-2026 project data). A 400-square-foot second story addition runs $150,000 to $250,000. Room extensions on the ground floor are generally $120,000 to $200,000. Permit fees add $5,000 to $15,000. Homes in fire zones may require additional Chapter 7A compliant materials.

Yes. All home additions in San Rafael require building permits from the San Rafael Building Division. This includes structural, electrical, plumbing, and mechanical permits. Hamilton Exteriors handles the entire permitting process — architectural drawings, structural engineering, plan submission, and inspection scheduling.

Most San Rafael home additions complete in 12 to 20 weeks from permit approval. Second story additions take 16 to 24 weeks due to structural complexity. Room extensions on an existing foundation complete faster at 10 to 14 weeks. Permit review adds 4 to 8 weeks before construction begins.

Most single-story San Rafael homes can support a second story with proper structural engineering. Our engineers assess your existing foundation, framing, and soil conditions. Common upgrades include foundation bolting and cripple wall bracing to meet California seismic standards. These upgrades typically add $10,000 to $25,000 but bring your entire home up to current code (Hamilton Exteriors 2024-2026 project data).

According to Remodeling Magazine's 2024 Cost vs. Value Report, well-executed home additions in the Pacific West recoup 50 to 70 percent of their cost at resale. In Marin County's high-value market, additions that add bedrooms or bathrooms often return more — particularly in neighborhoods where comparable homes with the added square footage sell at a significant premium.