Business Details
31 Years
experience
Denver's Trusted Window & Door Replacement Experts
303 Windows has been a trusted name in window and door replacement services for Denver and the Colorado Front Range since 1995. As a family-owned and locally operated business, we prioritize customer satisfaction through high-quality vinyl window and door installations tailored to withstand Colorado's diverse climate. Our team brings decades of combined experience, ensuring every project adheres to the highest standards of craftsmanship and durability. We specialize in energy-efficient solutions, offering products from reputable brands like Anlin, which provide superior thermal performance and long-term value.Our commitment to transparency, affordability, and personalized service has earned us a loyal customer base and industry recognition. From initial consultation to final installation, we guide homeowners through a seamless process, emphasizing clear communication and meticulous attention to detail. With a focus on sustainability, we help clients reduce energy costs while enhancing their home's aesthetic and functionality. Our reputation for reliability and excellence is reflected in countless positive reviews and repeat business, solidifying our position as Denver's premier window replacement provider.
Services
Vinyl Window Installation
Door Replacement
Energy Efficient Windows
Window Repair
Custom Window Solutions
Details
- Year established: 1995
Highlights and features
- We offer over 25 years of specialized window installation expertise in Colorado's climate
- Our team provides energy-efficient Anlin vinyl windows with lifetime warranties
- We guarantee transparent pricing with no hidden fees
- We maintain A+ BBB rating and hundreds of 5-star reviews
- We ensure precise installations completed by factory-trained professionals
What people say
Professional team
Energy savings
Competitive pricing
Hassle-free process
Lifetime warranties
Services
Vinyl Window Installation
Our vinyl window installation service transforms homes with durable, energy-efficient solutions designed for Colorado's climate. We specialize in full-frame replacements and new construction installations using Anlin's premium vinyl windows. Each project includes professional measurement, removal of old windows, and precise installation with weatherstripping and trim. These windows offer low maintenance, fade resistance, and thermal efficiency with options for custom colors and energy-saving glass packages.
Door Installation
We install high-performance vinyl patio doors that enhance home aesthetics and energy efficiency. Our offerings include sliding glass doors, French doors, and space-saving sliding French door configurations. Each installation features durable frames with weather-resistant seals, customizable glass options, and optional built-in pet doors or retractable screens. Our team ensures proper alignment and weatherproofing for smooth operation and improved insulation.
Energy Efficient Windows
Our energy-efficient window solutions reduce utility costs while maintaining comfort. Anlin windows feature Low-E glass coatings, argon gas fills, and triple-fin weatherstripping to minimize heat transfer. These windows meet ENERGY STAR standards and include NFRC-certified performance ratings for U-factor and solar heat gain. Proper installation ensures optimal thermal performance and long-term energy savings for Colorado homeowners.
Window Repair
We provide comprehensive window repair services for damaged or aging units. Our technicians address broken seals, cracked glass, and operational issues while maintaining warranty integrity. For windows beyond repair, we recommend cost-effective replacement solutions. Emergency repair services handle storm damage and insurance claims, working directly with homeowners' insurance providers for hassle-free processing.
Custom Window Solutions
Our custom window solutions accommodate unique architectural needs with various styles including bay, bow, and geometric windows. We offer 12 color options and specialty features like noise reduction glass and intrusion prevention systems. Custom sizing ensures perfect fit for renovations or new constructions, with professional consultation to optimize natural light and energy performance.
Questions
What window brands do you install?
We install Anlin vinyl windows, known for their energy efficiency, durability, and lifetime warranties. We previously worked with Amerimax and can service those installations as well.
Do you offer free estimates?
Yes, we provide free, no-obligation estimates for all window and door replacement projects in the Denver area.
How long does window replacement take?
Most complete home window replacements take 1-2 days. Installation timelines depend on project scope and current scheduling.
Are your installers employees or subcontractors?
All our installers are direct employees with factory training. Our team has worked together for years, ensuring consistent quality.
Do you handle insurance claims?
Yes, we work directly with insurance companies for storm damage claims. Our team documents damage and manages the claims process for homeowners.
What areas do you serve?
We serve Denver and the entire Colorado Front Range, including Boulder, Colorado Springs, and surrounding communities.
Videos
Reviews (5)
Laura Sabados
Jan 31, 2022
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We have used (303 Windows) to systematically replace all the windows in our home over the past 10+ years. This past September we scheduled our final installations for the bedrooms. My call was pleasantly greeted by Jay (the owner) who immediately referenced my account. Since it had been 3-4 years from our last installation, Jay personally came out to measure and evaluate a previous window that had failed. Due to the lifetime warranty, It was added it to the order to be replaced at no cost. The estimated time for installation for the bedroom windows was thought to be sometime around Christmas due
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. Im 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. Im so pleased that Im 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
Tracy C.
Oct 12, 2021
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Went with 303 windows because they were highly recommended and had great reviews. Maybe it was an off week for Jay, but we didn't have a great experience. Communication was poor about when the installers would arrive. I have kids and dogs and needed to have a window of time, but the installers' arrival was hours off Jay's estimate. Jay subs out the installation and that is really who you need to be good. We had one cracked window frame that the installers installed anyway. Jay replaced it, but we had to wait several weeks. In addition, unfortunately the installers also broke one
Shawn P.
Aug 21, 2021
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Jay and the crew did an amazing job with our windows. The whole process was easy and the price was great. I can't recommend them enough
