Replacement Windows - Denver, CO

For over five decades, Denver homeowners have trusted Gravina’s Window Center of Littleton® for top-quality window replacement. As Colorado’s oldest Marvin dealer, we specialize in energy-efficient fiberglass windows built to withstand harsh weather, improve your home's value, and reduce energy costs. Backed by an A+ BBB rating, a lifetime warranty, and 450+ five-star reviews, we’ve earned our reputation as Denver’s most trusted window company.

Marvin Fiberglass Windows & Doors

With energy-efficient fiberglass windows and doors, you can save money on your energy bills while enhancing the look and feel of your home. Trust the experts at Gravina's Window Center of Littleton^® to provide the best possible solution for your replacement needs. Our Marvin Infinity replacement windows guard your home from Rocky Mountain weather while increasing its value — plus, you'll save money on cooling costs year-round! Investing in superior fiberglass windows will ensure indoor comfort all day and give you priceless peace of mind. Don't go another season wondering if it's time to replace your existing windows or doors; trust Gravina's Window Center of Littleton^® as your go-to window company for worry-free results. Your home deserves nothing less. Trust the name your neighbors have relied on since the beginning.

Expert Window Replacement in Denver, CO

When you're ready to upgrade your Colorado home, trust the team that's been doing it right since 1973. At Gravina’s Window Center of Littleton®, we’re proud to be Colorado’s original Marvin Infinity dealer—bringing comfort, beauty, and lasting value to homes across Denver.

Our expert craftsmen don’t just install windows—they help transform your home with durable fiberglass windows and doors designed for the Rocky Mountain climate. From your first consultation to the final walkthrough, we make the process smooth, respectful, and refreshingly stress-free.

Your home deserves more than a quick fix—it deserves craftsmanship that stands the test of time. That’s why so many Denver homeowners have trusted us for generations. Ready to get started? Let’s make your home something you’re proud of again.

Denver’s Family-Owned Window Experts Since 1973

At Gravina’s Window Center of Littleton®, we don’t just replace windows—we deliver craftsmanship that’s been trusted for generations. As a family-owned business serving Colorado since 1973, our roots run deep, and so do our values: integrity, precision, and doing the job right the first time. When you choose Gravina’s Window Center of Littleton, you’re choosing a team that treats your home like our own—with care, respect, and unmatched experience.

Why Denver Homeowners Choose Gravina’s Window Center of Littleton®

Gravina’s Window Center of Littleton® has been Colorado’s trusted name in window replacement since 1973. As the state’s original Infinity from Marvin® dealer, we’ve helped thousands of homeowners across Denver upgrade their homes with confidence.

We’re a family-owned company committed to honest advice, premium products, and top-tier craftsmanship—no pressure or gimmicks. From bifold patio doors to James Hardie Siding and ProVia entry doors, we offer free consultations to help you find the best solution for your home’s unique needs.

Our Infinity fiberglass windows are built to last. They won’t warp, bow, or rot—and come in a wide range of styles and finishes to complement your home’s personality. Let our expert team guide you through a smooth, stress-free replacement process you’ll feel good about for years to come.

Gravina’s Window Center of Littleton^® is Colorado’s oldest Authorized Infinity window replacement company. We proudly serve Denver with industry-leading products including Infinity fiberglass windows and doors, James Hardie Siding, ProVia entry doors, and bifold patio doors. Backed by an A+ Better Business Bureau rating, our installations are completed with care, expertise, and pride.

Contact our team to get started with your free quote.

Explore Our Services

Quality Products. Professional Installation. No Guesswork.

Give us a call, and we’ll give you a
free, no-pressure quote
on Infinity from Marvin Windows. Discover why so many Denver homeowners trust Gravina’s Window Center of Littleton® to enhance their home’s beauty, comfort, and energy efficiency—with expert installation done right the first time.

What Are Infinity Windows?

Infinity® from Marvin Windows are made with
Ultrex® pultruded fiberglass—a material 8x stronger than vinyl and built to thrive in Colorado’s climate. These windows resist warping, leaks, and moisture damage to keep your home comfortable year-round.

Best of all, they’re virtually maintenance-free and built to stay beautiful for decades.
Infinity replacement windows offer clean lines, exceptional strength, and timeless style—inside and out.

Maximum Performance for Colorado Homes

With over 52 years of experience, Gravina’s Window Center of Littleton® understands Colorado’s extreme conditions. Our Infinity fiberglass windows seal tight, reduce energy loss, and enhance your home’s long-term value. We don’t just install windows—we deliver proven performance backed by local expertise.

Worry-Free Window Replacement

Denver homeowners can save on energy and elevate curb appeal with Infinity replacement windows and doors. These products are engineered for thermal performance with low-E glass coatings that resist heat and UV rays. Strong
fiberglass frames handle snow, sun, wind, and everything in between.

Choose from a variety of styles and colors to refresh your home’s look. With better insulation, you’ll enjoy year-round comfort and long-term energy savings. Investing in Infinity Windows means smart performance that pays you back every season.

Patio Doors

Upgrade your indoor-outdoor flow with Infinity from
Marvin fiberglass patio doors. These doors deliver long-lasting beauty, smooth operation, and improved energy efficiency—keeping your home warmer in winter and full of natural light in summer.

Our team installs every patio door with care, precision, and zero hassle. Whether you want sliding or hinged, classic or modern, Infinity patio doors offer security, style, and durability you can trust.

James Hardie Siding

James Hardie® siding offers exceptional performance and design flexibility for Colorado homes. It resists warping, pests, and fire—and it looks great doing it. Choose from a wide range of colors and textures to match your aesthetic.

For those looking to invest in James Hardie Siding, make sure you choose an experienced installer. Improper installation can shorten the product’s lifespan, while a seasoned team (like ours) ensures flawless results and long-term protection.

Fiberglass Replacement Windows

Marvin Infinity fiberglass windows are engineered for beauty, strength, and resilience. With
Infinity replacement windows made from
Ultrex® pultruded fiberglass, you’ll get years of reliable performance and a crisp, modern finish that never warps or rots.

Each window is built with advanced weather-resistant technology to block drafts, resist moisture, and handle Colorado’s harshest conditions. With Infinity, you get premium fiberglass windows that look incredible and require almost no maintenance—built to last, made to perform.

Our Promise to You

At Gravina’s Window Center of Littleton®, we’ve earned the trust of Colorado homeowners for over 52 years—one window, one door, and one family at a time. We don’t just install Infinity fiberglass windows—we stand behind every job like it’s our own home. From your first call to your final walkthrough, we’re committed to honest work, clear communication, and craftsmanship that lasts. Thanks for considering us. Whether it’s one window or a full-home replacement, we’re honored to help you improve your space—and we’ll treat your home with the same care and pride we give our own.