Hamilton Exteriors is headquartered in Castro Valley at 21634 Redwood Rd. We are your neighbors, not a drive-in crew. When you need window replacement, we are minutes away for measurements, consultations, and installation.
Now Booking Fall 2026: Schedule Your Consultation
Window Replacement Contractor in Castro Valley
500+ projects
Since 2018
Limited Lifetime
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Get a Free Window Estimate
We'll contact you in 3-5 minutes to discuss your window project.
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For local cost factors and planning, read our Window replacement cost guide for Castro Valley.
Your next step
Start Your Window Quote Online
Send your window count and project details. We will schedule measurements and review the product and installation options with you.
Window brands and contractor credentials
Customer-Service Obsessed
Responsive from consultation through project closeout
Architect and general contractor
One accountable team
Licensed, bonded, and insured
Verified business credentials
Window Styles 
Choose the Window Style That Fits the Opening
Single-Hung Windows
A fixed upper sash and operable lower sash for familiar operation, ventilation, and a straightforward replacement path.
Single-Slider Windows
Horizontal operation where exterior swing clearance is limited, with the opening and drainage details measured before ordering.
Sliding Glass Doors
Large glazed openings coordinated with sill support, flashing, drainage, operation, safety glass, trim, and adjacent finishes.
Picture Windows
Fixed glass for daylight and views, planned around glass size, exposure, energy ratings, structural support, and interior trim.
Double-Hung Windows
Two operable sashes for flexible ventilation, with frame proportions and trim selected for the home and opening.
Casement Windows
Hinged windows with compression seals, planned around swing clearance, hardware access, ventilation, and egress needs.
Castro Valley is unincorporated Alameda County, so window replacement permits go through the county. Energy upgrades and structural window modifications require permits. Hamilton Exteriors manages the county permit process for every window project.
Most Castro Valley homes were built between 1950 and 1980 with single-pane aluminum windows. These windows are drafty, conduct heat, and offer poor noise insulation. Upgrading to dual-pane vinyl or fiberglass windows reduces energy costs by 20 to 30 percent and meets California Title 24 energy standards.
Castro Valley's East Bay location means warm summers reaching 85 to 95 degrees. South and west-facing windows take intense afternoon sun. Low-E glass coatings and argon gas fills reduce solar heat gain while preserving natural light. For hillside homes with views, we install large picture and slider windows that maximize the panorama.
Neighborhoods We Serve
Window Replacement Across Castro Valley Neighborhoods
Local planning starts with the site, neighborhood context, access, and applicable city review.
Crow Canyon
Crow Canyon homes with hillside views benefit from large picture and slider windows. We install energy-efficient glazing that preserves the view while reducing heat gain from afternoon sun exposure.
Five Canyons
Five Canyons homes from the 1990s often have builder-grade vinyl windows ready for an upgrade. Premium vinyl and fiberglass frames with Low-E glass improve both energy efficiency and curb appeal.
Proctor
Proctor's 1950s ranch homes typically still have original single-pane aluminum windows. Replacement with dual-pane vinyl windows is one of the highest-impact upgrades for comfort and energy savings.
Palomares Hills
Palomares Hills properties feature larger windows on hillside elevations. We custom-size replacement windows to fit existing openings and add new windows where views and natural light can be improved.
Jensen Ranch
Jensen Ranch homes from the 1970s and 1980s often have dual-pane windows that have lost their seal, showing condensation between panes. Replacement restores clarity and insulation performance.
Greenridge
Greenridge homeowners often request noise-reducing glazing due to proximity to Castro Valley Boulevard and I-580. STC 30+ rated windows significantly reduce traffic noise while improving energy efficiency.
Fairview
Fairview area homes range from mid-century to modern construction. We match window styles to architectural period, from classic double-hung for traditional homes to casement windows for contemporary designs.
Lake Chabot Area
Homes near Lake Chabot enjoy natural surroundings and benefit from windows that connect indoor and outdoor spaces. Large sliders and picture windows frame the landscape while providing modern energy performance.
Project Management How Hamilton Exteriors
How Hamilton Exteriors
Manages Your Window Replacement
Opening Measurements
We measure each opening and review frame conditions, drainage, egress, safety glass, and trim before ordering.
Window and Glass Selection
Your proposal identifies the manufacturer, operating style, frame, glass package, energy rating, finish, hardware, and installation method.
Flashing and Installation
We coordinate removal, opening repairs, sill and perimeter flashing, insulation, window setting, trim, sealants, and permits.
Operation and Closeout
We test operation and locks, check sealants and finishes, complete cleanup, and review applicable product and workmanship warranties.
Google rating 4.6 ★ from 47 public reviews
Window Project Reviews
Verified public reviews from homeowners who hired Hamilton Exteriors.
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Renee D.
via HomeAdvisor
I scheduled to have someone come give me an estimate for all new windows in our 1950s home with not so great Remodeling work by previous owners. Alex Li promptly met with us & his crew throughout the entire process. They were always on time to work, left our home clean of debris & spectacular new JeldWin windows. Helped me with getting Financing as well...Just all around a great experience & highly recommend!
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Ethan W.
via HomeAdvisor
I recently hired Hamilton Exteriors to replace my siding and windows, and they did a fantastic job. Their team was punctual, polite, and paid close attention to detail. The siding looks seamless, and the new windows have made a noticeable difference in both appearance and energy efficiency. Communication was always clear, and they finished on time and within budget. I’m very happy with their work and would definitely recommend them.
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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.
H
H.T.
via Google
I had a great experience working with Hamilton exteriors. From start to finish, their team was professional, responsive, and detail-oriented. They made the entire process smooth and stress-free, keeping me updated every step of the way. The quality of their work really stands out. Everything was done efficiently and exceeded my expectations. If you’re looking for a reliable company that takes pride in what they do, I highly recommend them!
Google rating: 4.6/5 from 47 public reviews
Read reviews on Google Mid Market
Window Replacement Costs in Castro Valley
$8,000–$25,000
Median home value in Castro Valley: $1,050,000
Prices for 8–15 window replacements in a typical Castro Valley home. Individual windows: $500–$1,200 installed depending on size, type, and frame material. Actual costs depend on window count, sizes, and project complexity. Free, itemized estimates provided.
Get Your EstimateCompare Broad Window Operation Types
Swipe to compare all options.
| Feature | Single Hung | Double Hung | Casement | Slider | Picture |
|---|---|---|---|---|---|
| Operation | Lower sash moves | Both sashes move | Hinged sash opens | One sash slides | Fixed glass |
| Ventilation path | Lower opening | Upper and lower openings | Full sash opening | Half of frame opening | None |
| Clearance review | Interior access | Interior access | Exterior swing area | Track and meeting rail | Glass and trim access |
| Main detail focus | Sash balance and seal | Two sash seals | Hardware and compression seal | Track and drainage | Glass, frame, and flashing |
| Dedicated guide | Single hung | Double hung | Casement | Single slider | Picture window |
Window Financing
Plan Your Window Replacement With Approved Credit
Financing may be available for eligible multi-window and whole-home replacement projects with approved credit. During your window consultation, we review the product and installation scope, then explain current lender programs, terms, and payment timing.
Ask which current options fit your window replacement project.
Call Now (650) 977-3351 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, Greater Sacramento, and the Central Valley. Our published guides cover 14 counties and 88 cities. Our Castro Valley and Sacramento offices support local estimating, permit coordination, and project planning across these regions.
How does billing and financing work?
Financing may be available for eligible projects with approved credit. Available terms depend on lender approval, project scope, and current programs. Your project manager can review the options that apply before work begins. We also accept checks, ACH, and major credit cards.
Are you licensed and insured?
Yes. Hamilton Exteriors holds CSLB License #1078806, active general liability coverage, and the required contractor bond. We also hold GAF Master Elite and James Hardie Elite Preferred credentials. We can provide current proof of coverage before work begins.
Do I need a permit for my exterior project?
Permit requirements depend on the project scope and local jurisdiction. Hamilton Exteriors coordinates required applications, plan documents, corrections, and inspections. Permit fees and allowances appear in the proposal before construction begins.
How much does window replacement cost in Castro Valley?
Window replacement in Castro Valley costs $600 to $1,500 per window installed, depending on the style and frame material. A typical home with 10 to 15 windows runs $8,000 to $18,000 for a full replacement. Every Hamilton Exteriors estimate is itemized — window units, trim, flashing, labor, and cleanup listed separately. Get Your Free Quote for a precise estimate for your home.
Do I need a permit for window replacement in Castro Valley?
Yes. Alameda County requires a building permit for window replacement. Permit fees range from $200 to $600 (Hamilton Exteriors 2024-2026 project data). Hamilton Exteriors handles the permit application and all required inspections. We include the permit fee as a separate line item in your estimate.
How long does window replacement take in Castro Valley?
Most Castro Valley homes with 10 to 15 windows take 1 to 2 days to complete. Each window takes approximately 45 to 90 minutes to remove, prep, install, insulate, flash, and trim. We install one window at a time and seal each opening before moving to the next, so your home is never left open to the elements.
What window brands do you install?
We install Milgard, Andersen, and Marvin windows. All three brands offer ENERGY STAR certified options with U-factors as low as 0.25, exceeding California Title 24 requirements. We also offer factory-direct pricing on GAF and Owens Corning roofing systems for customers combining window and roof replacement projects.
Do new windows save money on energy bills?
Yes. ENERGY STAR certified windows save Bay Area homeowners $125 to $465 per year on energy bills, according to the U.S. Department of Energy. Castro Valley homes with single-pane aluminum windows see the largest savings because the upgrade to dual-pane Low-E glass is substantial.
Your Next Step
Plan Your Project With a Clear Scope
Financing may be available with approved credit for eligible projects.
Tell us about your project. We usually call within 3–5 minutes to schedule the next step.
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21634 Redwood Rd Unit F, Castro Valley, CA 94546
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