Expert remodeling
Window Installation & Replacement in Long Island, NY
40 Years of Experience
Certified Professionals
Superior Workmanship with Proven Reputation
Stress-Free Process
Thermo-Seal Windows, Siding & Roofing, Inc.
Window Replacement in Long Island That Blends Beauty With Energy Efficiency
Looking for professional window installation in Long Island, NY? Thermo-Seal has been providing trusted window replacement services to Long Island homeowners for over 40 years. From Nassau to Suffolk County, we install energy-efficient windows that elevate home design while improving comfort and performance—whether you're in Garden City, Huntington, or anywhere in between.
We never outsource. Every window project is completed by our in-house, factory-trained professionals for precision, consistency, and peace of mind. If your current windows are drafty, outdated, or difficult to open, Thermo-Seal delivers Long Island window solutions designed to last.
Thermo-Seal Exterior Remodeling
Full-Service Window Installation in Long Island for Year-Round Comfort
Long Island’s weather can be unpredictable—icy winters, salty air, and humid summers all take a toll. That’s why we install windows from trusted brands like Andersen, engineered to perform in every season and reduce energy waste in your home.
✔ Installed by certified, full-time Thermo-Seal pros
✔ Built to handle Long Island’s coastal and seasonal extremes
✔ Custom styles to match every type of Long Island home—from historic to contemporary
Why Long Island Homeowners Choose Thermo-Seal for Window Replacement
With more than 20,000 exterior projects completed since 1985, Thermo-Seal is a name homeowners across Long Island recognize and trust. Our focus on craftsmanship, product quality, and reliable service sets us apart.
Why Long Island residents choose Thermo-Seal:
✔ Andersen Certified – Experts in energy-efficient, high-performance windows
✔ No Subcontractors – Our in-house team handles every installation
✔ A+ BBB Rating – Long-standing reputation built on customer satisfaction
✔ Weather-Ready Products – Windows that resist wear from coastal conditions
✔ Energy Efficiency – Reduce heating and cooling costs year-round
From Montauk to Mineola, Thermo-Seal installs windows on Long Island that look great and perform even better.
Window Replacement in Long Island That Solves Common Homeowner Issues
Old or inefficient windows don’t just look outdated—they can increase utility bills, let in noise, and reduce comfort. Thermo-Seal’s window replacements on Long Island tackle these issues while enhancing your home’s appearance and energy profile.
✔ Drafty Interiors? Our insulated windows block outside air and seal in comfort
✔ Difficult to Open or Close? Modern windows offer easy, secure operation
✔ Skyrocketing Energy Bills? Energy-saving glazing helps cut costs
✔ Street Noise or Disruptions? Choose multi-pane options for quieter interiors
Thermo-Seal delivers window installations on Long Island that solve real problems while adding value and peace of mind.
Schedule Your Free Estimate Today
Ready to transform your home’s exterior with expert remodeling that lasts? Contact Thermo-Seal today for a free in-home estimate and experience why thousands of homeowners across New York and Connecticut trust us for windows, siding, roofing, doors, and more.
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Service Area
Services We Offer:
Upgrade Your Home Now & Pay Later – Interest Free!
For a limited time, enjoy convenient financing with 0% interest for up to 25 months.
Contact Info.
Phone Number:
Email Address:
Showroom:
456 Sunrise Highway, Rockville Center NY 11570 - (516) 689-7214
Rye Corporate Office:
411 Theodore Fremd Avenue, Rye NY 10580 - (914) 635-3748
Stamford Office:
263 Tresser Blvd., Stamford, CT 06901 - (203) 990-1812
Melville Office:
68 South Service Road., Melville NY 11747 - (631) 710-6937
CLIENT REVIEWS
What Our Clients Are Saying About Us
Thermo-seal Windows provides exceptional customer service alongside high-quality products. Recently, I had the majority of my home's windows replaced by Aaron's team, and their performance was nothing short of impressive. They arrived on time, maintained a tidy work area, and dedicated themselves to ensuring a perfect installation of the windows.
Aaron and his team were amazing, from start to finish! They worked with us every step of the way and Aaron was always just a call or text away to answer any questions we had. The windows are perfect and we love them. We highly recommend working with Aaron and his team. They are professional, courteous and their work is top notch!
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