Second story additions in San Francisco

We serve six Bay Area counties — Alameda, Contra Costa, Marin, Napa, San Mateo, and Santa Clara — covering 47 cities from Oakland to San Jose. Our crews are based in Castro Valley, putting us within 45 minutes of every city we serve. We handle permits and know the building codes for each jurisdiction, which matters because requirements and fees vary significantly between cities.

We offer $0-down financing with approved credit, 12-month same-as-cash plans, and extended terms up to 15 years for larger projects. You only pay for completed, inspected work — we never ask for full payment before the job is done. Your project manager will walk you through every option during your estimate appointment. We also accept checks, ACH, and all major credit cards.

Yes. CSLB License #1078806 — verify it anytime at cslb.ca.gov. We carry $2M general liability, full workers’ comp, and are bonded per California law. We hold GAF Master Elite, Owens Corning Preferred, CertainTeed ShingleMaster, and James Hardie Elite Preferred certifications — each requires annual training and quality audits to maintain. We’re happy to provide proof of insurance before any work begins.

Most exterior projects in the Bay Area require a building permit. Fees vary by city — Oakland runs $200–$600, Peninsula cities often more. We handle the entire permit process: application, plan submission, and scheduling inspections. Permit fees appear as a separate line item in your estimate so you’ll see every cost upfront. For homes in WUI fire zones (Berkeley Hills, Oakland Hills, parts of Marin), we ensure full compliance with local fire-rated material requirements.

Second story additions in San Francisco typically run $425 to $650 per square foot, putting an 800-1,200 sq ft addition at roughly $340,000 to $750,000 fully built. Costs are higher than the broader Bay Area because of DBI and Planning permit fees, mandatory seismic upgrades on pre-1978 homes, and the prevailing labor rates in the city. Every Hamilton Exteriors estimate is fully itemized so you see exactly what each phase costs.

Yes. Almost every second story addition in San Francisco triggers a Section 311 neighborhood notice, which gives neighbors within 150 feet 30 days to request a Discretionary Review hearing at the Planning Commission. Our team prepares the notice package and walks you through what to expect. We have shepherded projects through DR hearings and design well within RH-1 and RH-2 zoning to minimize the chance of a contested hearing.

Plan on 6 to 12 months from application to issued building permit for a second story addition in San Francisco. Planning review takes 3 to 5 months, the 311 neighborhood notice adds 30 days, and DBI plan check runs 2 to 4 months in parallel. Active construction is typically 18 to 24 weeks once permits issue. We start the permit process immediately after design approval so we can stack timelines.

For most second story additions in San Francisco, you can stay in the home for the first 8 to 12 weeks while we build the addition above the existing roof under temporary weather protection. The 4 to 6 week window where we cut into the existing ceiling and tie in stairs typically requires temporary relocation. We coordinate move-out timing in your project schedule and build it into the contract.

We build second story additions across all of San Francisco, including the Sunset, Richmond, Noe Valley, Bernal Heights, Glen Park, the Mission, Potrero Hill, Pacific Heights, and the Marina. We pay particular attention to historic districts like Alamo Square and Liberty Hill where Historic Preservation Commission review applies, and we have completed projects in every major SF zoning district.