ADU Builder in Palo Alto

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.

Most ADU contractors in Palo Alto are tradesmen-only — they build from plans provided by an outside architect. This creates a natural gap between design intent and construction reality. When the architect and builder are the same entity, that gap disappears. An architect-led approach means your ADU's design accounts for construction methods, material availability, and site conditions from the first sketch. Change orders during construction are rare because the design was created by the people wh

A detached ADU in Palo Alto typically costs $275,000 to $500,000 for a 600 to 800 square foot unit with mid-range finishes (Hamilton Exteriors 2024-2026 project data). Garage conversions run $150,000 to $250,000. Junior ADUs (JADUs) start around $150,000. Permit and impact fees add $15,000 to $30,000. These numbers include design, engineering, permits, and construction but exclude furniture, landscaping, and optional upgrades like solar panels.

Plan on 10 to 16 months total from design start to move-in. Design and engineering take 2 to 4 months. Permit review in Palo Alto typically takes 8 to 12 weeks. Construction runs 4 to 6 months for a detached ADU or 10 to 14 weeks for a garage conversion.

Yes. All ADUs in Palo Alto require a building permit from the city's Planning and Development Services Department. California state law streamlines the process, but you still need approved plans and inspections. Building without permits creates code violations, insurance gaps, and complications when you sell.

If you own a single-family home in Palo Alto, you almost certainly can. State law (AB 68, SB 13) overrides most local zoning restrictions. Your lot must meet 4-foot rear and side yard setbacks, and the ADU cannot exceed certain size limits. A site feasibility review confirms what's possible on your specific property.