ADU Contractor in Redwood City

We serve Northern California across three regions: the San Francisco Bay Area (six counties from Alameda to Santa Clara), Greater Sacramento (Sacramento out to Roseville, Folsom, and Davis), and the Central Valley (Stockton to Modesto). Our crews are based in Castro Valley. 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 Northern California 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.

ADU costs in Redwood City typically range from $150,000 to $350,000 depending on size, finishes, and whether it's a new build or garage conversion. With median home prices at $1,750,000, an ADU can add significant value. We provide free consultations with detailed estimates.

California's ADU laws make it possible to build on most residential lots in Redwood City. San Mateo County has streamlined the permitting process. We evaluate your property's potential during our free consultation, including setbacks, utility access, and local zoning.

From design to move-in, most ADU projects in Redwood City take 8-12 months. The San Mateo County permitting process typically takes 60-90 days, and construction runs 4-6 months. Our 60-day permit guarantee keeps your timeline on track.

Yes. We handle all ADU permitting in Redwood City and throughout San Mateo County — architectural plans, structural engineering, Title 24 energy compliance, and city submissions. Our 60-day permit guarantee means we manage the entire process.

In Redwood City, you can build detached ADUs (up to 1,200 sq ft), garage conversions, attached additions, and junior ADUs (up to 500 sq ft). Many homeowners in Downtown Redwood City are choosing detached ADUs for rental income or multi-generational living.

Yes. Redwood City requires building permits for all ADU construction. The Community Development Department processes ADU applications with a streamlined review track. The city provides an ADU resource guide and pre-application consultation to clarify requirements before formal submission. Hamilton Exteriors handles the complete permit process from site assessment through final inspection.

Redwood City allows detached ADUs up to 1,200 square feet, attached ADUs, garage conversions, and JADUs up to 500 square feet. The city also permits an ADU and JADU on the same single-family lot. Two-story detached ADUs are allowed where zoning permits, giving homeowners on smaller lots the option to build up rather than out.

Yes. Redwood City allows long-term ADU rentals without owner-occupancy requirements. The city does not apply rent control to ADUs in most cases. Short-term rentals are regulated under the city's home-sharing ordinance. One-bedroom ADUs in Redwood City rent for $2,200 to $3,200 per month, reflecting strong demand from nearby tech workers.

Redwood City follows California's 4-foot minimum rear and side setback for detached ADUs. Existing structures being converted, including garages, may retain their current setbacks. Properties in Emerald Hills and the western hills may have additional slope-based setback considerations. We verify all setback requirements during the initial property evaluation.

Redwood City ADUs typically add $175,000 to $350,000 in property value depending on size and finish level. With median home prices near $1.6 million, the percentage increase is meaningful. Properties near downtown and Redwood Shores see particularly strong ADU-driven appreciation due to walkability and employment proximity.

Popular financing options include HELOCs, cash-out refinancing, and construction loans. CalHFA offers predevelopment grants up to $40,000 for qualifying California homeowners. Redwood City's high home values provide most homeowners with sufficient equity for HELOC-based financing. Hamilton Exteriors connects clients with lenders who specialize in ADU construction projects.

A Junior ADU (JADU) is a unit of 500 square feet or less built within your existing home. Redwood City allows one JADU per single-family lot alongside a standard ADU. JADUs cost $80,000 to $150,000 and are the most affordable path to adding a rental unit. They work well in Redwood City's larger homes where a bedroom or bonus room can be converted with minimal structural changes.