Room Addition in Redwood City, CA

Quartz Construction designs and builds room additions in Redwood City, CA. Whether you need a master suite, family room, home office, additional bedroom, or in-law suite, our licensed team delivers full design-build services from permits to final walkthrough. Licensed CSLB #1003436 | BBB A+ | 4.9⭐ (65+ Reviews)

Room Addition Cost in Redwood City

A room addition in Redwood City typically costs $210,000–$470,000 depending on size, room type, and finish level. A basic bedroom addition (200 sq ft) starts around $55,000–$90,000. A master suite with bathroom (500–600 sq ft) runs $130,000–$260,000. Second story additions cost more at $300–$500/sq ft due to structural engineering and roof removal.

Types of Room Additions We Build in Redwood City

• Master Suite Addition — Bedroom, walk-in closet, and en-suite bathroom. Most popular addition in Redwood City for homeowners staying long-term
• Family Room Addition — Large open-concept entertainment space, often extending from the kitchen
• In-Law Suite — Ground-floor bedroom + bathroom for aging parents or adult children
• Home Office Addition — Dedicated work-from-home space with proper lighting and electrical
• Bedroom Addition — Adding a 3rd, 4th, or 5th bedroom for growing families
• Second Story Addition — Double your home’s footprint on small Redwood City lots
• Sunroom / 3-Season Room — Glass-enclosed addition for California indoor-outdoor living

Room Addition Process in Redwood City

• 1. Free Assessment: We visit your home, evaluate the site, and discuss your goals
• 2. Design: Architectural drawings and structural engineering
• 3. Permits: We handle all Redwood City building permits and plan check
• 4. Construction: Foundation, framing, mechanical, drywall, finishes
• 5. Inspection & Completion: Final city inspection and project completion

Call Quartz Construction at (650) 749-7436 for a free room addition consultation in Redwood City. CSLB #1003436 | BBB A+ | Serving Redwood City and all Bay Area cities.