More room to live,without moving.
Bedrooms, family rooms, and second-story additions — built to match your existing home.
- CSLB B #1150085
- Permits handled
- Licensed · Bonded · Insured
- San Mateo & Santa Clara
Everything your room additions needs.
Real credentials. No surprises.
Financing available — up to $200,000, APR from 7.99%, soft credit check that won't affect your score.
Room Additions — FAQ
How much does a room addition cost in the Bay Area?+
Ground-floor additions typically run $400–$650 per square foot. A second-story addition runs $500–$800 per sq ft because of foundation reinforcement, stairs, and roof work. A 400 sq ft master suite addition usually lands between $180,000 and $280,000.
How long does a room addition take?+
Most single-room additions take 3–5 months of construction after permits are issued. Permits run 2–4 months in most Peninsula cities. Expect 6–9 months total from signed contract to move-back-in.
Do I need a permit for a room addition?+
Yes. Any addition that changes the home's footprint, roofline, or square footage requires a building permit, structural review, and Title 24 energy compliance. We handle all city paperwork and inspections.
Can I stay in my home during the addition?+
Usually yes. We seal off the construction zone, keep your kitchen and at least one bathroom operational, and schedule loud or dusty work during the day. For full second-story additions, most homeowners move out for 2–4 weeks during framing and roof tie-in.
Let's walk your project.Free, no-pressure estimate.
Tell us what you're planning. We'll come out, listen, and give you a clear path forward.