Room Addition in Pleasant Hill CA — Home Additions & Second Story | Quartz Construction
Quartz Construction & Remodeling builds room additions in Pleasant Hill, CA. Serving homeowners throughout Contra Costa County, our licensed general contractors (CSLB #1003436) design and build home additions that add living space, increase home value, and keep your family in the neighborhood you love. Room additions in Pleasant Hill are often more cost-effective than buying a larger home — you avoid real estate commissions, transfer taxes, and moving costs while staying in your established community. Call (650) 749-7436 for a free room addition estimate in Pleasant Hill.
Room Addition Types We Build in Pleasant Hill, CA
Industry Resources & Standards:
- Primary Suite Addition: The most popular room addition in Pleasant Hill — adding a new primary bedroom with en-suite bathroom, walk-in closet, and potentially a sitting area. Transforms a 3/2 into a 4/3 home, significantly increasing resale value in the Pleasant Hill real estate market.
- Family Room Addition: Expanding the main living area — typically an open-concept family room addition that connects to the kitchen or existing living room. Includes new flooring, recessed lighting, and often sliding glass doors to the backyard.
- Second Story Addition: Add an entire floor to a single-story Pleasant Hill home — gaining 600-1,500+ sq ft without using any backyard space. Most cost-effective when the existing foundation and structure can support the added weight (engineering assessment required).
- Bump-Out Addition: A smaller addition (50-300 sq ft) that extends a single room — commonly the kitchen, primary bath, or a bedroom. Cost-effective because it doesn’t require a full foundation and can be completed in 4-8 weeks.
- Garage Conversion to Living Space: Converting an attached garage to a family room, bedroom, home office, or ADU. Extremely popular in Pleasant Hill where living space is at a premium. Full insulation, drywall, flooring, HVAC, and electrical upgrade included.
- Sunroom / Four-Season Addition: Enclosed sunroom or all-season room addition with large windows and proper insulation for Contra Costa County climate. Connects interior living to outdoor views while maintaining the home’s thermal envelope.
- Home Office Addition: Dedicated home office space addition — increasingly popular in Pleasant Hill among tech workers and remote employees who need a professional workspace separate from the main living areas.
- In-Law Suite Addition: Ground-floor bedroom with en-suite bathroom designed for aging parents, multigenerational living, or eventual conversion to ADU rental income. Can be designed to meet ADA accessibility standards.
Room Addition Cost in Pleasant Hill 2025
| Addition Type | Typical Size | Cost Range |
|---|---|---|
| Bump-out addition (single room extension) | 100 – 300 sq ft | $60,000 – $130,000 |
| Single bedroom addition | 150 – 250 sq ft | $80,000 – $160,000 |
| Primary suite addition (bedroom + bath) | 300 – 600 sq ft | $150,000 – $350,000 |
| Full first-floor addition (multiple rooms) | 500 – 1,000 sq ft | $250,000 – $550,000 |
| Second story addition (full floor) | 800 – 1,500 sq ft | $350,000 – $700,000 |
| Garage conversion to living space | 200 – 500 sq ft | $60,000 – $140,000 |
Get a Free Room Addition Estimate in Pleasant Hill
Contact Quartz Construction & Remodeling for room additions in Pleasant Hill, CA. We handle design, permit application, structural engineering coordination, construction, and finish work — start to finish. CSLB #1003436 | BBB A+ | 4.9 Stars. Call (650) 749-7436.
What Our Clients Say
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Professional Resources & Regulations
- California Contractors State License Board (CSLB) — Verify contractor licenses
- City of San Jose Building Permits — Permit requirements & inspections
- ENERGY STAR — Energy-efficient materials & standards
Trusted by San Jose Homeowners
4.9/5.0 • 65+ Google Reviews
“Amazing kitchen remodel — on time, on budget. Highly recommend Quartz Construction!”
— Maria S., San Jose
“Professional, communicative, and the bathroom renovation exceeded expectations.”
— David L., Santa Clara
“Built our ADU from scratch — permits, foundation, everything handled seamlessly.”
— Jennifer T., Sunnyvale
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Licensed • CSLB#1003436 • Serving San Jose & Bay Area
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