Room Addition Cost in Pasadena, CA (2026)
A room addition in Pasadena costs $345–$690 per sq ft, with a typical mid-size room addition running $127k–$253k. Small projects start around $58k; large or high-end work can reach $460k or more.
Costs in Pasadena run about 15% above the LA County baseline due to historic preservation overlays and craftsman-style detailing.
Room Addition Cost by Size in Pasadena
Totals adjusted for the Pasadena market (1.15× LA County baseline). Ranges include labor, materials, permits, and contractor overhead.
| Size | Type | Range | Low | High |
|---|---|---|---|---|
| Small | Bump-out / single room | 150–250 sq ft | $58k | $127k |
| Medium | Suite addition | 300–500 sq ft | $127k | $253k |
| Large | Second story / multi-room | 600+ sq ft | $230k | $460k |
What Affects Room Addition Cost in Pasadena?
- Foundation type.
- Roofline integration.
- MEP (mechanical/electrical/plumbing) extension.
- Permits.
- Soil condition.
- Pasadena market premium: local pricing reflects historic preservation overlays and craftsman-style detailing, which shifts totals about 15% above the LA County baseline.
Get exact room addition bids in Pasadena
We'll match you with up to 3 licensed Pasadena contractors.
Get MatchedRoom Addition Sub-Type Comparisons
Bedroom Addition vs Master Suite Addition
A standard bedroom addition runs $50k–$110k; a master suite (bedroom + bath + walk-in closet) doubles the plumbing scope and lands at $110k–$220k.
Second Story Addition vs Sunroom Addition
Second-story additions require foundation reinforcement and full re-roof at $200k–$400k; sunrooms (prefab or stick-built) skip much of the structural work at $30k–$90k.
How to Get the Best Price on a Room Addition in Pasadena
- Get 3 line-itemized bids on the same scope through Keystone Connect — Pasadena room addition pricing varies 10–25% between contractors.
- Lock major materials and finishes before signing; mid-project change orders are the #1 cost driver on room addition jobs.
- Bid in shoulder seasons (Jan–Mar or Sep–Oct) when Pasadena contractor schedules are open and rush premiums disappear.
- Verify CSLB license, insurance, and bond before paying any deposit. California caps deposits at $1,000 or 10% of contract, whichever is less.
Frequently Asked Questions — Room Addition in Pasadena
Need more answers? Visit our contractor FAQ hub.
Get Matched with Licensed Pasadena Contractors
Tell us about your room addition and we'll match you with up to 3 vetted contractors.