Business Details
31 Years
experience
Denver's Premier Vinyl Window & Door Replacement Experts
303 Windows has been a trusted name in Denver's window and door industry since 1995. As a family-owned business, we specialize in vinyl window and patio door installation, serving homeowners across the Colorado Front Range. Our team combines 30 years of experience with partnerships with top manufacturers like Anlin to deliver energy-efficient, durable solutions tailored to Colorado's climate. We prioritize clear communication, free estimates, and a six-step installation process that ensures precision and customer satisfaction.Our commitment to quality is reflected in our use of replacement-grade vinyl products that outperform builder-grade alternatives, offering superior insulation and longevity. We take pride in our local expertise, understanding the unique demands of Colorado weather, and treating every customer with the respect and care we would extend to our own neighbors.
Services
Window Installation
Door Installation
Vinyl Windows
Patio Doors
Window Replacement
Energy Efficient Windows
Custom Windows
French Doors
Awning Windows
Bay Windows
Details
- Year established: 1995
Highlights and features
- We offer 30 years of specialized window installation expertise
- Our team uses only ENERGY STAR-rated Anlin vinyl products
- We provide free estimates with no-pressure consultations
- Our installation process includes professional removal of old windows
- We're locally-owned and understand Colorado's climate challenges
What people say
Professional team
Competitive pricing
Energy savings
Quick installation
Excellent service
Services
Vinyl Window Installation
Our vinyl window installation service transforms homes with durable, energy-efficient solutions. We specialize in replacing old windows with Anlin vinyl products that offer superior insulation and require minimal maintenance. The installation process includes professional measurement, removal of existing windows, and precise fitting with proper weatherstripping. Homeowners benefit from reduced energy bills, enhanced curb appeal, and long-lasting performance that withstands Colorado's variable climate conditions.
Patio Door Installation
We provide premium vinyl patio door installation that combines functionality with aesthetic appeal. Our selection includes sliding glass doors and French doors with energy-saving features like Low-E glass and thermal breaks. The installation process ensures proper sealing and smooth operation while matching existing window styles. These doors enhance natural light, improve energy efficiency, and create seamless transitions between indoor and outdoor spaces.
Energy Efficient Windows
Our energy-efficient window options feature advanced technologies including Low-E coatings, argon gas fills, and multi-chambered vinyl frames. These components work together to minimize heat transfer, reduce UV damage, and maintain consistent indoor temperatures. Certified by ENERGY STAR and the National Fenestration Rating Council, our windows help homeowners lower utility costs while improving overall home comfort in Colorado's climate.
Custom Window Solutions
We offer customized window solutions to match unique architectural styles and functional requirements. From specialty shapes to color-matched frames and grid patterns, our customization options ensure seamless integration with existing home designs. The service includes personalized consultations to determine optimal window configurations for light control, ventilation, and aesthetic harmony with the property's exterior.
Window Replacement Process
Our structured six-step replacement process begins with a comprehensive consultation and measurement phase. We provide detailed cost estimates before ordering precision-fitted windows. The installation phase includes careful removal of old windows, proper disposal, and meticulous fitting of new units with attention to weatherproofing details. This systematic approach ensures minimal disruption and guarantees proper installation that maximizes product performance and longevity.
Questions
What window types do you offer?
We offer Anlin vinyl windows including double-hung, casement, awning, bay, picture, and specialty shapes. Our selection includes energy-efficient options with Low-E glass and argon gas fills.
Do you provide free estimates?
Yes, we offer free, no-obligation estimates for all window and door replacement projects in the Denver area.
Are your installers certified?
Our team has 30 years of combined experience and receives ongoing training in proper installation techniques for optimal performance.
How long does installation take?
Most full-home window replacements complete in 1-2 days, with individual window installations often finished in a single day.
Do you work with insurance claims?
Yes, we assist with insurance claims for storm damage including hail, wind, and broken glass replacements.
What warranty do you offer?
We provide Anlin's lifetime warranty on windows and a comprehensive warranty covering both product and installation workmanship.
Videos
Reviews (5)
Blaise Singer
Jun 25, 2022
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Wow! I am so impressed! I love my new windows! Jay is honest, responsive and professional. He is very knowledgeable and has great ideas. Jay and his installers, Rich and Mike, were very respectful to me and my home. They did what they said they would do. The install was fast and they kept my home clean during the process. I was very nervous and hesitant about the whole process, but I'm so glad I used 303 Windows. I couldn't be happier!
A. W.
Mar 16, 2022
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We worked with Jay replacing over 40 outdated Viking windows in our house with Amerimax Craftsman windows, advice and insights he provided were very helpful. He gave us a number of references which all commented very positively on their related projects. The at times difficult measurement and install was looked after by John and his team of professional and courteous installers and worked out very well. Follow-up work on our end after the install was completed was minimal. Jay followed up on manufacturing issues when the manufacturer was simply not responsive and also addressed incorrectly delivered window panes and exterior caulking issues, the latter representing the main challenge we had so far.
Unfortunately Jay does not seem to be available/interested in smaller projects, we are planning to install three new windows in locations that don't have windows today, despite contacting 303 windows multiple times we never heard back.
Unfortunately Jay does not seem to be available/interested in smaller projects, we are planning to install three new windows in locations that don't have windows today, despite contacting 303 windows multiple times we never heard back.
Jay J.
Jan 12, 2022
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My experience with Jay, the owner, was fantastic from the minute I talked to him on the phone. He was on time, professional and listened to want we wanted to do with our windows. He had several windows and took the time to explain the differences between the windows. No pressure. It was an easy choice to have Jay install the new windows. When the windows arrived, he called and set up a time for installation.
His crew was very professional, answered my questions and took the time to make sure the work area was spotless before they left. The new windows look fantastic! If you need new windows, don't waste your time calling anyone else.
His crew was very professional, answered my questions and took the time to make sure the work area was spotless before they left. The new windows look fantastic! If you need new windows, don't waste your time calling anyone else.
Nancy Dilatush
Dec 22, 2021
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I would highly recommend 303 Windows because of service, price and Jay's vision. When I asked for a quote, it was for 4 bedroom windows, very straight forward. Jay saw the large picture window and sliding glass door in my living room and he made a suggestion. Needless to say, I took his advice and the large picture window looks better than I imagined it could. I'm very happy with the windows, the installation (installer was great) and Jay's vision!
Donna Lefferdo
Oct 28, 2021
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I used 303 Windows to replace some of my old inefficient windows in my house and install their white vinyl windows. Jay Lillien came out to do an estimate. I'm amazed at how affordable these windows are compared to other companies. He was very helpful and knowledgeable of the style to fit my house and design. The installation team was very professional and did a beautiful job. I'm so pleased that I'm having them finish the rest of the windows in the house! These windows are so energy efficient and attractive. I love my new kitchen view, family room view and the rain glass in the bathroom.
