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Hamilton Exteriors — Northern California roofing, siding, and exterior remodeling
4.8-star rated by 39 verified Northern California homeowners

CSLB #1078806 · Architect & General Contractor · Building Northern California homes since 2018

Additions Contractor in Redwood City

Serving Redwood City & San Mateo County
Licensed & Insured
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Hamilton Exteriors provides professional additions services in Redwood City, California. Licensed under CSLB #1078806, we handle all Redwood City building permits and inspections. Call (650) 977-3351 for an estimate.

Local Expertise

Home Additions in Redwood City: What Local Homeowners Need to Know

Many Redwood City homes — especially 1950s-60s ranches and tract homes in Woodside Plaza and Redwood Village — were built when families and living patterns were smaller. UV degradation and thermal cycling crack composition shingles 3-5 years faster than coastal cities. Original stucco on 1950s ranches develops extensive hairline cracking from expansion/contraction. often surface during addition projects, and we address them as part of the build.

Redwood City's climate — warmest microclimate on the Peninsula — summer highs 85-95°F. South-facing Emerald Hills homes get intense UV. Limited fog penetration compared to coastal San Mateo County. — directly impacts home additions performance and material selection. The most common issues we address in Redwood City include UV degradation and thermal cycling crack composition shingles 3-5 years faster than coastal cities. Original stucco on 1950s ranches develops extensive hairline cracking from expansion/contraction.. Hamilton Exteriors selects materials proven for Redwood City's Title 24 Climate Zone 3 conditions and backs every installation with our 50-year warranty.

Redwood City's housing stock spans 10% pre-1940, 30% 1940-1960, 30% 1960-1985. Architectural styles range from 1950s-60s ranches and tract homes in Woodside Plaza and Redwood Village to turn-of-century Victorians and Craftsmans downtown. Each era and style presents different home additions requirements — from material compatibility to structural considerations. Our crews know what to expect before they arrive on site.

Factory-certified by our manufacturer partners

Owens Corning Preferred Contractor
CertainTeed ShingleMaster
GAF Master Elite Contractor
Tesla Powerwall Certified
James Hardie Elite Preferred
Rated 4.8 ★ from 39 Verified Northern California Homeowners

What Homeowners Say About Our Work

Real reviews from verified Northern California homeowners.

deborah maxey, Hamilton Exteriors customer

deborah maxey

in the last week

Great job and very professional the 1st photo is before and the other 2 is upon completion of work.

E

Eric W.

via Yelp

Hamilton Exteriors did an amazing job on my roof. The team was professional, and the quality of work was top-notch. Highly recommend!

R

Robert H.

via Angi

From the very first consultation, we knew we'd made the right choice. The team was knowledgeable and genuinely listened to our concerns about energy efficiency and design. We've already noticed a drop in our energy bills.

L

Laura G.

via Nextdoor

Hamilton Exteriors repaired extensive dry rot damage on our home's exterior. Their attention to detail and commitment to quality were evident throughout the project. Our home looks better than ever.

Northern California home with financing options available through Hamilton Exteriors
Financing Options

Financing Options Available For Everyone

Most Northern California exterior projects range from $15,000 for a standard roof replacement to $600,000 for a custom ADU — and paying out of pocket isn't the only option. Hamilton Exteriors partners with multiple lending providers to offer $0-down financing with approved credit, 12-month same-as-cash plans, and extended terms up to 15 years for larger projects. You only pay for completed, inspected work — we never ask for full payment before the job is done. Whether you're replacing a roof, upgrading siding, or building an ADU, your project manager will walk you through every payment option during your free estimate so you can choose what fits your budget.

Ask about same-as-cash plans during your estimate.

Premium Market

Home Additions Costs in Redwood City

$210,000–$450,000

Median home value in Redwood City: $1,750,000

Prices reflect Redwood City's premium market and San Mateo County labor rates. Actual costs depend on home size, materials, and project complexity. We provide free, itemized estimates with no hidden fees.

Get Your Estimate

Rated 4.8 stars by Northern California homeowners across BBB, Trustpilot, Google, and Yelp

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Rated 4.8/5.0

What Types of Home Additions Are Available?

Second Story Additions by Hamilton Exteriors in Northern California

Second Story Additions

Double your living space without giving up yard. We handle structural engineering, load calculations, and permits for full second-story builds. Most projects completed in 8-12 weeks.

Room Extensions by Hamilton Exteriors in Northern California

Room Extensions

Expand your kitchen, add a bedroom, or open up your living area with a seamless room addition. We match your existing roofline, siding, and finishes so it looks like it was always there.

ADUs & Guest Houses by Hamilton Exteriors in Northern California

ADUs & Guest Houses

Detached ADUs, garage conversions, and junior ADUs that add living space and rental income. Full design-build with our 60-day permit guarantee. Bay Area ADU experts since 2020.

Full Remodels by Hamilton Exteriors in Northern California

Full Remodels

Gut renovations that transform your entire home. We handle demo, structural changes, electrical, plumbing, and finishing — one team managing every trade so nothing falls through the cracks.

Neighborhoods We Serve

Home Additions Across Redwood City Neighborhoods

Friendly Acres

Friendly Acres homeowners frequently choose Hamilton Exteriors for home additions. Many Redwood City homes — especially 1950s-60s ranches and tract homes in Woodside Plaza and Redwood Village — were built when families and living patterns were smaller. With Redwood City's Peninsula warm pocket: summer highs 80-95°F, winter lows 38-48°F, material selection in Friendly Acres requires local expertise.

Woodside Plaza

In Woodside Plaza, homes are predominantly turn-of-century Victorians and Craftsmans downtown. UV degradation and thermal cycling crack composition shingles 3-5 years faster than coastal cities. Our crews are familiar with Woodside Plaza's architectural character and building requirements.

Farm Hill

From Farm Hill to Friendly Acres, Redwood City homeowners trust Hamilton Exteriors for home additions that stands up to warmest microclimate on the Peninsula — summer highs 85-95°F. South-facing Emerald Hills homes get intense UV. Limited fog penetration compared to coastal San Mateo County.. We handle permits, engineering, and installation — you get a single point of contact.

Emerald Hills

Emerald Hills homeowners frequently expand with second-story additions that capture Peninsula views. Hillside construction requires structural engineering expertise. Hamilton Exteriors evaluates slopes and foundations before designing.

Redwood Shores

Redwood Shores additions often extend living areas toward yard space. Waterfront-adjacent homes need careful moisture management. Our team designs additions that harmonize with the community's planned aesthetic.

Stambaugh-Heller

Stambaugh-Heller offers varied lot sizes that accommodate different addition types. Whether a ground-floor expansion or a second-story build, our structural engineer determines the right approach for your specific home.

Our Advantage

Why Choose
Hamilton Exteriors?

Transparent Pricing

Every estimate is itemized line by line — materials, labor, permits, cleanup. You see exactly where your money goes before we start.

Factory Trained Installers

Every crew member is manufacturer-certified and vetted — licensed, bonded, insured, and background-checked before they touch your home.

50-Year Warranty

50-year manufacturer warranty backed by our own workmanship guarantee for the full duration. If anything fails, we fix it — free.

Your Own Project Manager

One dedicated point of contact from first call to final walkthrough. You’ll always know who to reach.

Our Latest Projects

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Architectural Shingle Roof Replacement in Antioch Roofing

Architectural Shingle Roof Replacement

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Jun 25, 2026

Architectural Shingle Roof Replacement in Fremont Roofing 3

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Products

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Jun 10, 2026

Architectural Shingle Roof Replacement in Fremont — photo 2Architectural Shingle Roof Replacement in Fremont — photo 3
New Roof Installation in Hayward Roofing

New Roof Installation

Location

Hayward

Products

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Jun 5, 2026

Full Roof Replacement in Walnut Creek Roofing

Full Roof Replacement

Location

Walnut Creek

Products

GAF Architectural Shingles

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Jun 2, 2026

James Hardie Siding Installation in Pleasanton Siding

James Hardie Siding Installation

Location

Pleasanton

Products

James Hardie

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May 28, 2026

GAF Roof Replacement in Oakland Roofing

GAF Roof Replacement

Location

Oakland

Products

GAF Architectural Shingles

Completed

May 15, 2026

Architectural Roof Replacement in Berkeley Roofing

Architectural Roof Replacement

Location

Berkeley

Products

GAF Architectural Shingles

Completed

Apr 10, 2026

Frequently Asked Questions

Didn't find the answer to your question? Call Now (650) 977-3351

What areas do you serve?

We serve Northern California across three regions: the San Francisco Bay Area (six counties from Alameda to Santa Clara), Greater Sacramento (Sacramento out to Roseville, Folsom, and Davis), and the Central Valley (Stockton to Modesto). Our crews are based in Castro Valley. We handle permits and know the building codes for each jurisdiction, which matters because requirements and fees vary significantly between cities.

How does billing and financing work?

We offer $0-down financing with approved credit, 12-month same-as-cash plans, and extended terms up to 15 years for larger projects. You only pay for completed, inspected work — we never ask for full payment before the job is done. Your project manager will walk you through every option during your estimate appointment. We also accept checks, ACH, and all major credit cards.

Are you licensed and insured?

Yes. CSLB License #1078806 — verify it anytime at cslb.ca.gov. We carry $2M general liability, full workers’ comp, and are bonded per California law. We hold GAF Master Elite, Owens Corning Preferred, CertainTeed ShingleMaster, and James Hardie Elite Preferred certifications — each requires annual training and quality audits to maintain. We’re happy to provide proof of insurance before any work begins.

Do I need a permit for my exterior project?

Most exterior projects in Northern California require a building permit. Fees vary by city — Oakland runs $200–$600, Peninsula cities often more. We handle the entire permit process: application, plan submission, and scheduling inspections. Permit fees appear as a separate line item in your estimate so you’ll see every cost upfront. For homes in WUI fire zones (Berkeley Hills, Oakland Hills, parts of Marin), we ensure full compliance with local fire-rated material requirements.

How much does a home addition cost in Redwood City?

Home additions in Redwood City typically cost $200-$500 per square foot depending on scope and finishes. A second story addition usually runs $250,000-$500,000. With median home prices at $1,750,000 in Redwood City, adding space is often more economical than moving. Free consultations available.

Can I add a second story to my home in Redwood City?

Most single-story homes in Redwood City can support a second story addition with proper structural engineering. We evaluate your foundation, framing, and local zoning during our free consultation. Many homes in Emerald Hills have successfully added second stories.

How long does a home addition take in Redwood City?

Most home additions in Redwood City take 3-6 months from permit to completion. Second story additions are typically 4-6 months. We handle all San Mateo County permits and manage construction so you have one point of contact.

Does Hamilton Exteriors handle permits for additions in Redwood City?

Yes. We handle all permitting for home additions in Redwood City and San Mateo County — architectural plans, structural engineering, and city submissions. We work with Redwood City planning departments regularly.

Can I live in my home during the addition in Redwood City?

In most cases, yes. We phase construction to minimize disruption. For second story additions, there may be a brief period where certain rooms are inaccessible. We create a detailed plan before starting so you know exactly what to expect.

Do I need permits for a home addition in Redwood City?

Yes, all home additions in Redwood City require building permits from San Mateo County. We handle permit applications, structural engineering, plan check responses, and all inspections. Our CSLB #1078806 license covers the full scope of work.

Should I build a second story or a ground-floor addition in Redwood City?

This depends on your lot size, foundation, and zoning in Redwood City. Ground-floor additions use yard space but avoid structural upgrades. Second stories preserve yard but require foundation evaluation. We assess both options during consultation.

Does my foundation support a second-story addition in Redwood City?

Many Redwood City homes built in the 1950s-60s ranches and tract homes mixed with turn-of-century Victorians era may need foundation reinforcement for a second story. Our structural engineer evaluates your existing foundation and designs any necessary upgrades. This assessment is part of our design process.

How much value does an addition add to a Redwood City home?

Home additions in Redwood City typically return 50-70% of their cost at resale. In the Peninsula market at $1,750,000 median values, added square footage directly increases your home's competitive position and livable space.

Does Hamilton Exteriors handle the design for additions?

Yes, our architect-led design-build team creates addition plans that integrate with your existing Redwood City home's architecture. We handle design, engineering, permits, and construction under one contract for a seamless experience.

Ready to start? (650) 977-3351

Call now — we pick up in minutes. Or fill out the form above and we'll call you.

21634 Redwood Rd Unit F, Castro Valley, CA 94546

Serving Oakland, Berkeley, Fremont, San Jose, Palo Alto, Walnut Creek, San Rafael, Napa, Redwood City & more across Alameda, Contra Costa, Marin, Napa, San Mateo & Santa Clara counties. All 47 cities →