Room Additions in San Jose, CA

Ground-level room additions -- extra bedroom, family room, or expanded living space built onto your existing home.

4 - 7 months (design + permit + construction)1-year workmanship warranty

Starting at $60,000|Typical range: $60,000 - $200,000

Based on square footage, foundation type, and finish level. A typical 200-400 sq ft bedroom addition falls in the lower half of this range.

About Our Room Additions Service

Whether you need a fourth bedroom for a growing family or a larger family room for entertaining, a ground-level room addition extends your existing footprint without the cost of a second story. We match the addition's roofline, siding, and windows to your home's existing architecture so it looks original, not bolted-on. Every addition includes full structural engineering, San Jose permit submission, and a foundation designed for your specific soil conditions.

What's Included

Seamless roofline and exterior material matching

Structural engineering and permit drawings included

New foundation, framing, and full weatherproofing

HVAC extension or new zone as needed

Interior finish -- flooring, drywall, paint, trim

City permit and final inspection coordination

Our Process

Design & Engineering

We design the addition to match your home's existing style and get structural plans stamped by a licensed engineer.

Permitting

Plans go to San Jose Building for review; we manage corrections and keep the project moving through plan check.

Foundation & Framing

Foundation is poured to match your home's existing structure, then framing ties the addition into the main roofline.

Finish & Inspection

Drywall, flooring, paint, and trim bring the space to move-in condition, followed by final city inspection.

Why Room Additions Matters

Adds usable square footage without a second story
Increases home resale value
Custom-designed to match existing architecture
Full permit and inspection compliance
Structural engineering included for San Jose soil conditions

Frequently Asked Questions

Will my room addition match the rest of my house?

Yes -- we match roofline pitch, siding material, window style, and trim details so the addition reads as part of the original structure, not a visible add-on.

Do I need to move out during construction?

Most homeowners stay in their home during a room addition. We section off the work area and maintain safe access to the rest of the house throughout construction.

Can you add a bathroom to a bedroom addition?

Yes, many of our bedroom additions include an attached bathroom or walk-in closet. We size the plumbing and framing for this during the design phase.

Room Additions Service Areas

We provide room additions across San Jose and the South Bay, including:

San Jose Santa Clara Sunnyvale Cupertino Campbell Los Gatos Saratoga Milpitas Mountain View Morgan Hill

Get a Free Quote

Free on-site estimate

Starting at

$60,000

Based on square footage, foundation type, and finish level. A typical 200-400 sq ft bedroom addition falls in the lower half of this range.

Text Us Request Online Quote

Duration

4 - 7 months (design + permit + construction)

Warranty

1-year workmanship warranty

Other Services

Why Choose Us

Licensed, Bonded & Insured
Design-Build Under One Contract
Permit & Inspection Handled
Free On-Site Estimates
Satisfaction Guaranteed
South Bay Local

Get Your Free Estimate Today

Whether you need a new ADU, a room addition, or a full second story, our team is ready to scope your project. Text us now for a free on-site estimate.

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Since 2011

South Bay Local

Licensed

Bonded & Insured

10+

Cities Served

Free

Estimates Always