ODL Construction

San Mateo, California

Home Additions in San Mateo

Room additions, primary suites, and second stories that look original to the home.

Looking for home additions in San Mateo? ODL Construction is a licensed Bay Area general contractor serving San Mateo and the surrounding Peninsula — from San Mateo Park, Aragon, Hillsdale and beyond. Room additions, primary suites, and second stories that look original to the home.

In a market where moving up costs hundreds of thousands in transaction costs and a bigger mortgage, adding on is often the smarter play — especially in top-school neighborhoods where the right addition returns more than a relocation. The key is an addition that looks like it was always there, not bolted on.

For San Mateo specifically, it comes down to local realities: San Mateo's mix of period San Mateo Park homes and mid-century neighborhoods rewards remodels that match the era — generic finishes underperform here. San Mateo's building department is established and consistent; older neighborhoods can add character and tree considerations on exterior work. We design and permit your home additions around exactly those conditions.

Home Additions in San Mateo — what we handle

  • Room and bedroom additions
  • Primary-suite additions
  • Second-story additions
  • Bump-outs and rear extensions
  • Structural engineering and foundation work
  • Roofline and exterior matching
  • Zoning, setback, and design-review compliance
  • Permits and inspections

Home Additions cost

Single-room addition$100,000 – $200,000
Primary-suite addition$150,000 – $300,000
Second-story addition$300,000 – $600,000+

Typical Bay Area ranges, not a quote. Additions price by square footage, structural complexity, and foundation work. Second stories cost more because the floor below must be reinforced. You get a fixed proposal after design.

Timeline

Room additions typically run 3–5 months; second stories 5–9 months, including design, engineering, and permitting.

San Mateo permits

San Mateo's building department is established and consistent; older neighborhoods can add character and tree considerations on exterior work.

Licensed & Accountable

One licensed team that stands behind the whole project

ODL Construction is a licensed and insured Bay Area general contractor. 35 years building in the Bay Area, We design, permit, and build under one roof — one contract, one schedule, one accountable party from first sketch to final walkthrough. Our license is California Licensed Contractor — CSLB #1154902.

  • Licensed & insured
  • Design–build under one roof
  • Permits & inspections handled
  • Serving all four Bay Area counties
ODL Construction

Free Consultation

(408) 418-9277

CSLB #1154902

Verify our license at CSLB →

Home Additions in San Mateo — FAQs

Do you offer home additions in San Mateo?

Yes — San Mateo is part of our core San Mateo County service area. We handle home additions for San Mateo homeowners end to end, including the city's permitting.

How do San Mateo's permit rules affect my home additions?

San Mateo's building department is established and consistent; older neighborhoods can add character and tree considerations on exterior work. We scope your San Mateo permit timeline up front so your schedule is realistic, and we manage drawings, applications, and inspections for you.

Is it cheaper to add on or to move?

Often adding on wins — when you factor in agent commissions, transfer taxes, a higher mortgage rate, and the school-area premium you'd pay elsewhere, building bedrooms onto the home you own frequently costs less and builds equity. We'll help you compare.

Can I add a second story to my home?

Sometimes — it depends on your city's zoning and whether your neighborhood has a single-story overlay (common in some Sunnyvale and Palo Alto Eichler tracts). We check first and design a ground-floor or detached alternative if a second story isn't allowed.

Start your project

Get a free home additions quote in San Mateo

Tell us about your project and we'll arrange a complimentary consultation across the Bay Area. Or call (408) 418-9277 to speak with us directly.

(408) 418-9277

35 years of experience · Licensed & insured · Design–build

Request a consultation

We'll respond promptly.

Prefer to talk? Call (408) 418-9277

(408) 418-9277Consultation