Fort Collins (970) 517-3931
Colorado Springs (719) 270-4494

Infinity from Marvin Window Options in Fort Collins & Colorado Springs, CO

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According to HomeAdvisor, 25% of the costs for heating and cooling your home comes from the energy lost through your windows.

Carefully considering which type of window is right for your home could save you thousands of dollars in energy costs, while increasing the resale value of your home.

Did you know?

In independent market studies, they have noted that 65% of service related issues to prematurely failed windows are related to improper installation.

This is due to short cuts during the installation of windows, low-cost faulty sealants and improper flashing methods. There is something to be said for doing a job right the first time, and being able to put your name on it. Nex-Gen strives for quality over quantity when it comes to home window replacement and are constantly raising the bar in the window replacement industry. We live by the code: A product is only as good as the Installation behind it.

Exterior Colors

We use a proprietary acrylic finish on our Ultrex® fiberglass that’s virtually impermeable to help protect your investment from wind, weather and color fading.

Stone White



Pebble Gray


Bahama Brown


Interior Colors

We use the same acrylic finish on our interior as on our exterior for superior performance. Or choose our EverWood® option for the classic appeal of wood.

Stone White




EverWood®, our breakthrough engineered wood grain interior finish, offers natural looks and textures — plus the durability you expect. It looks, feels, paints and stains like wood but is completely low maintenance.


We’ve curated a wide variety of hardware finish options so you can find the perfect choice for your home’s style.


We offer two screen options — Standard or Hi Transparency for a clearer, brighter view. Screen frames are color matched to the window for a seamless look.



Decorative Glass

Specialty Glass


Tempered Glass

Increases glass strength to help prevent breakage. This option is ideal for windows that are close to the floor or located in high-traffic areas.


Laminated Glass

Even more durable than tempered glass, laminated glass is often referred to as impact resistant or safety glass due to its vinyl interlayer that tends to remain in place when cracked.



Sound Transmission Class and Outdoor-Indoor Transmission Class Glass has increased pane thickness, ideal in areas where exterior noise is a concern.

Low E Insulating Glass Coatings

Extremely thin coatings of special low emissivity (Low E) metallic material are applied to glass panes to boost their energy efficiency and block out UV rays. Since glass choice plays a big factor in window and door efficiency, your local Infinity partner can provide recommendations on the best selection for your home.

Low E1

Primarily used in colder climates, Low E1 allows more heat in to warm a room while blocking heat loss.

Low E2

By reflecting heat back to its source, Low E2 offers year-round performance in moderate climates. Low E2 will help retain heat in your home during the winter and keep heat out during the summer.</span

Low E3

Low E3 is formulated to reject solar heat while letting light in, resulting in increased performance in climates with intense sun exposure.

Low E3/ERS

With an extra metallic layer on the room-side glass to reflect escaping heat back into the room, Low E3/ERS provides maximum efficiency year round in all conditions.

Simulated Divided Lites

Grilles Between the Glass

Grilles and Divided Lites

Simulated Divided Lites

Our Simulated-Divided-Lite (SDL) bars are built with Ultrex® fiberglass. Permanently adhered in our factory to the outside surfaces of the glass, SDLs have a spacer bar between the panes of glass to offer the traditional look of divided lites.

Grilles Between the Glass

Located between the panes of insulating glass, Grilles-Between-the-Glass (GBG) combine easy cleaning with the timeless detail of a grille pattern.


We offer various divided lite patterns so you can replicate the look of your original windows and doors – or add new architectural interest to your home.

Standard Rectangular

Rectangular One-High

Prairie Six-Lite

Prairie Nine-Lite

Cottage One-High

Open Hub Sunburst

Prairie Four-Lite One-High

Prairie Six-Lite

Standard Rectangular/Cottage One-High/Standard Regtangular


According to HomeAdvisor, 25% of the costs for heating and cooling your home comes from the energy lost through your windows.

Carefully considering which type of window is right for your home could save you thousands of dollars in energy costs, while increasing the resale value of your home.

Also, independent market studies have noted that 65% of service related issues to prematurely failed windows are related to improper installation. This is due to:

  • short cuts during the installation of new or replacement windows
  • low-cost faulty sealants
  • improper flashing methods
infinity from marvin replacement windows nex-gen windows and doors

What are the best replacement windows for my home?

We’re making it easier for you to buy replacement windows and doors by sharing what to expect during your project. Learn more about how you can find the best window for your home.


A few months ago I researched different companies for our HOA because several neighbors had said they wanted to replace some or all of their windows. Of the four companies I checked, Nex-Gen was the one we all chose.

Ted is great, friendly and knowledgeable and helpful. He has done work here for several residents. And now he’s helping me too. I’m very happy working with Ted and I know I’ll be happy with the windows that he’ll have installed in my home!

Lead safe EPA
better business bureau accredited business nex-gen windows and doors in colorado springs, co
Energy Star (2000x2000)
Marvin green logo and trust building marvin windows and doors nex-gen windows and doors


1. Expert Consultation

A Nex-Gen windows and doors expert will provide a complete consultation to determine your specific needs — including climate considerations and other factors. They will answer all your questions and provide a detailed, custom project quote based on your specifications.

2. A Perfect Fit

We’ll review your order, measure your openings and verify your installation needs. Your windows will then be built to your exact needs and measurements.

3. Seamless Installation

We’ll remove and dispose of your old windows, and replace them with your custom Infinity windows.

4. Built for Life®

From our Limited Lifetime Warranty to unparalleled customer service, we go above and beyond to ensure your windows provide a lifetime of optimal performance.


At Nex-Gen we’re changing the way Window & Door replacement has been done in the past. Our Expert Staff will provide industry leading solutions for your home improvement needs. The right product for your budget and desired functionality. Our promise is to provide a low pressure, educative consultation while allowing you to be the judge to make the right decision for your homes’s needs.

  • 1

    Let’s Begin

    We start with a phone call to collect information about your home, your replacement needs, and your goals. Every project is unique; we learn as much as we can upfront to ensure a successful remodel experience.

  • 2


    We visit your home to get a first-hand look at the project and to familiarize you with our process. We discuss products and innovative solutions, and provide a transparent cost vs. value analysis and detailed proposal.

  • 3


    Our Elite Window Experts take meticulous measurements to ensure a smooth installation. Accurate window measurements also maximize energy efficiency and protect the aesthetics of your home.

  • 4


    You stay informed with periodic updates via phone, email or text. Scheduling changes are sometimes unavoidable due to the manufacturer’s date changes or inclement weather. We keep you posted in real time.

  • 5


    Our installers come and go with minimal disruption to your routine. No need to leave your home; most installations are completed in 1-2 days. Our crew members receive special training and pass background checks.

  • 6


    Upon completion, the lead installation tech does a walk-through final inspection. He provides operating instructions for your new windows and doors and reviews the warranty information.

  • 7

    Let Us Know

    We ask that you complete a survey as the final step in our process. Collecting feedback about your experience keeps us on our toes. If we didn’t meet your expectations, we want the opportunity to make it right.

“Serving Northern Colorado From Fort Collins to Denver, Estes Park to Greeley – We’re here for you.”

Improving your home, protecting your investment