Bay Area's Architect-Led Custom Home & Exteriors Contractor

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.

A full roof replacement in the San Francisco Bay Area typically costs between $15,000 and $100,000, depending on roof size, pitch, and material. Asphalt shingle roofs — installed on 75% of U.S. homes according to the Asphalt Roofing Manufacturers Association — start around $1,075 per roofing square. Metal roofing starts at $1,525 per square and reflects up to 70% of solar radiant heat (Oak Ridge National Laboratory, DOI:10.2172/1220146). Tile and slate cost more but can last 50–100 years. Permit fees in Bay Area counties range from $200 to $800, with Alameda and Santa Clara counties typically at the higher end. Hamilton Exteriors provides detailed square-footage pricing in every estimate so you can compare materials side by side before committing.

Most residential roof replacements take 2–5 days of on-site work once materials arrive. Siding projects run 1–3 weeks depending on square footage. Window replacements average 1–2 days for a full home. Larger projects like ADUs and additions take 4–8 months from permit to move-in. Every Hamilton Exteriors estimate includes a written timeline with milestones so you know exactly what to expect. Your project manager sends daily photo updates through CompanyCam so you can track progress from anywhere.

A design-build contractor handles both the architectural design and construction under one contract, one team, and one point of accountability. This eliminates the coordination gaps that happen when you hire a separate architect and builder. Hamilton Exteriors is led by a licensed architect (Alexander Hamilton Li) who also holds a General Contractor license (CSLB #1078806), which means your project is designed and built by the same person — reducing change orders, shortening timelines, and keeping the original design intent intact from blueprint through final inspection.

Hamilton Exteriors offers a transferable 50-year warranty on roofing and siding installations, which stays with the home if you sell — making it a documentable asset in any real estate transaction. This is backed by manufacturer warranties from GAF, Owens Corning, CertainTeed, and James Hardie — we hold their highest-tier certifications, which require annual training and quality audits to maintain. Windows carry manufacturer warranties of 20–30 years depending on the product line. Our workmanship warranty covers labor for the full duration, not just the first few years. If an issue arises five, ten, or twenty years after installation, our warranty covers the repair at no additional cost to you. Every warranty is documented in writing before work begins.