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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

ADU Contractor in Lafayette

Serving Lafayette & Contra Costa County
Licensed & Insured
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Hamilton Exteriors provides professional adus services in Lafayette, California. Licensed under CSLB #1078806, we handle all Lafayette building permits and inspections. Call (650) 977-3351 for an estimate.

Local Expertise

ADU in Lafayette: What Local Homeowners Need to Know

With 5% pre-1940 in Lafayette, many properties have room for an ADU alongside the original structure. aging 1950s-60s roofing stock on second or third replacement cycle often make ADU construction the ideal time to address deferred maintenance on the primary residence.

Lafayette's climate — sheltered inland valley with summer highs 88-98°F, Diablo winds funnel through Reliez Valley gap with gusts to 60 mph — directly impacts adu performance and material selection. The most common issues we address in Lafayette include aging 1950s-60s roofing stock on second or third replacement cycle and original wood shake needing fire-safe conversion on hillside homes. Hamilton Exteriors selects materials proven for Lafayette's Title 24 Climate Zone 12 conditions and backs every installation with our 50-year warranty.

Lafayette's housing stock spans 5% pre-1940, 15% 1940-1959, 40% 1960-1979. Architectural styles range from 1950s-60s California ranch and split-levels on quarter- to half-acre lots in Burton Valley to 1930s-40s cottages near downtown. Each era and style presents different adu requirements — from material compatibility to structural considerations. Our crews know what to expect before they arrive on site.

Lafayette sits in a valley that traps summer heat (high 90s) while its hillside properties face significant wildfire risk as part of the Lamorinda fire zone. Our ADU designs for Lafayette incorporate high-performance insulation, energy-efficient HVAC systems, and strategic window placement to ensure year-round comfort without excessive utility costs.

Lafayette features large-lot homes from the 1950s-70s alongside custom hillside estates, with median home values exceeding $2 million in this affluent Lamorinda community. The existing housing stock presents diverse opportunities for ADU construction, from garage conversions in older neighborhoods to detached new builds in communities with larger lots.

The City of Lafayette Building Department handles permits with care for hillside development regulations and fire-safe construction requirements, typically in 4-6 weeks. Hamilton Exteriors (CSLB #1078806) navigates the ADU permitting process in Lafayette, ensuring compliance with both state ADU laws and local zoning requirements for efficient project approval.

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

ADU Costs in Lafayette

$300,000–$600,000

Median home value in Lafayette: $1,900,000

Prices reflect Lafayette's premium market and Contra Costa 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 ADU Services Are Available?

Detached ADUs by Hamilton Exteriors in Northern California

Detached ADUs

Standalone backyard homes that offer maximum privacy and flexibility. Perfect for guest suites, rental units, or home offices. We handle design, engineering, permits, and construction from start to finish.

Design & Architecture by Hamilton Exteriors in Northern California

Design & Architecture

Our in-house architects create custom ADU floor plans, 3D renderings, and construction documents tailored to your lot. We maximize square footage within local zoning codes and design for natural light, privacy, and flow.

Engineering & Permits by Hamilton Exteriors in Northern California

Engineering & Permits

We handle structural engineering, Title 24 energy compliance, and all permit applications. Our 60-day permit guarantee means your project stays on schedule. Bay Area ADU permitting is complex — we navigate it daily.

Garage Conversions by Hamilton Exteriors in Northern California

Garage Conversions

Transform your existing garage into a fully functional living space. Garage conversions are the most cost-effective ADU option — no new foundation required. We handle structural modifications, utilities, and finishes.

Neighborhoods We Serve

ADU Across Lafayette Neighborhoods

The Trails

The Trails homeowners frequently choose Hamilton Exteriors for adu. With 5% pre-1940 in Lafayette, many properties have room for an ADU alongside the original structure. With Lafayette's Summer average 90°F with 5-10 days above 100°F, material selection in The Trails requires local expertise.

Downtown Lafayette

In Downtown Lafayette, homes are predominantly 1930s-40s cottages near downtown. aging 1950s-60s roofing stock on second or third replacement cycle often make ADU construction the ideal time to address deferred maintenance on the primary residence.. Our crews are familiar with Downtown Lafayette's architectural character and building requirements.

Springhill

From Springhill to Burton Valley, Lafayette homeowners trust Hamilton Exteriors for adu that stands up to sheltered inland valley with summer highs 88-98°F. We handle permits, engineering, and installation — you get a single point of contact.

Happy Valley

Happy Valley in Lafayette has strong rental demand, making ADUs an excellent investment. Many homeowners use their ADU for family members or generate $2,000-$3,500 in monthly rental income.

Burton Valley

Lot configurations in Burton Valley often accommodate detached ADUs in rear yards with separate entrances for privacy. We design layouts that maximize living space while meeting setback requirements.

Trails

Garage conversions are popular in Trails where existing two-car garages provide a cost-effective starting point for ADU construction at roughly 30% less than new builds.

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

Powered by BackOffice
Architectural Shingle Roof Replacement in Antioch Roofing

Architectural Shingle Roof Replacement

Location

Antioch

Products

GAF Architectural Shingles

Completed

Jun 25, 2026

Architectural Shingle Roof Replacement in Fremont Roofing 3

Architectural Shingle Roof Replacement

Location

Fremont

Products

GAF Architectural Shingles

Completed

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

GAF Architectural Shingles

Completed

Jun 5, 2026

Full Roof Replacement in Walnut Creek Roofing

Full Roof Replacement

Location

Walnut Creek

Products

GAF Architectural Shingles

Completed

Jun 2, 2026

James Hardie Siding Installation in Pleasanton Siding

James Hardie Siding Installation

Location

Pleasanton

Products

James Hardie

Completed

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 an ADU cost in Lafayette?

ADU construction in Lafayette typically ranges from $150,000 to $350,000 depending on size, finishes, and site conditions. Garage conversions start lower while detached new builds cost more.

Can I build an ADU on my property in Lafayette?

California's ADU laws allow construction on most residential lots in Lafayette. We evaluate your property's potential during a free consultation, including setbacks, utilities, and zoning compliance.

How long does it take to build an ADU in Lafayette?

From design to move-in, an ADU in Lafayette typically takes 8-14 months. Permitting accounts for 2-4 months, with construction taking 4-8 months depending on complexity.

What lot size do I need for an ADU in Lafayette?

Under California law, most single-family lots in Lafayette can accommodate an ADU regardless of lot size. Setback requirements are typically 4 feet from side and rear property lines.

What types of ADUs can I build in Lafayette?

Lafayette homeowners can build detached ADUs (up to 1,200 sq ft), attached ADUs, garage conversions, or JADUs (up to 500 sq ft within the existing home). Each type has different cost and timeline considerations.

Can I rent out my ADU in Lafayette?

Yes. ADUs in Lafayette can be rented at market rates with no owner-occupancy requirement for properties with only one ADU. This makes them an excellent investment for rental income.

What are the setback requirements for ADUs in Lafayette?

Detached ADUs in Lafayette require 4-foot side and rear setbacks. Converted garages and structures within the existing footprint may qualify for reduced setback requirements.

How much value does an ADU add to a Lafayette home?

ADUs in Lafayette typically add 20-30% to property value while generating $2,000-$3,500 monthly rental income. The combination of equity growth and cash flow makes ADUs a strong investment.

What financing options are available for ADUs in Lafayette?

Lafayette homeowners can finance ADUs through home equity loans, cash-out refinancing, construction loans, or the California ADU Grant Program. We help connect you with experienced ADU lenders.

What is a JADU and can I build one in Lafayette?

A Junior ADU (JADU) is a unit up to 500 sq ft created within your existing home footprint. JADUs in Lafayette have simplified permitting and lower construction costs, typically $50,000-$100,000.

Ready to start? (650) 977-3351

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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 →