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Your Windows Your Way

We are Colorado’s most trusted source for replacement windows, doors, and siding. 
Book your free design consult or continue reading to learn more about our available products and services.


New windows provide beauty, protection, insulation, and value to your home. Click to view our premium collection of replacement windows hand-selected by a Colorado local.


Extend a warm welcome to every visitor through a beautifully crafted front door. We offer a variety of options to match the style, design, or function you’re looking for. 


Improve curb appeal, protect your home from the elements, lower your energy bill, and dampen outside noise all with the help of LP SmartSlide siding.

Local Expert Service From Our Family To Yours

Nex-Gen Windows & Doors is the local favorite among Colorado homeowners.


Known for premium materials such as Infinity from Marvin, our Lifetime Installation Warranty, and exceptional service, we’re equipped to help with all your window, door, or siding needs.


Click to learn more about the products, services, and team members that make Nex-Gen Windows & Doors the right choice for your next home improvement project.

Why Settle?

Don’t settle for high energy bills and outdated designs in your home. Many of competitors present inaccurate quotes, use scare tactics and are pushy to get you buy products that are not right for your home. When it comes to installation, they can be messy and damage your property.

You Deserve More.

What Others Are Saying

I did quite a bit of research before purchasing and they had a great price for the work I wanted to get done. The workmanship was top notch and I plan to use them again.

Jamie Underwood

We have very large windows that face southwest which were replaced with new Marvin fiberglass windows 3 years ago. They are FABULOUS! There is a noticeable difference with heating and cooling bills. Ted has been amazing! Now he is back to finish up with the northeast-facing windows.

Kathy Bragg

I had these guys install a sliding glass door. It was spring so we had a couple weather glitches. They got the job done and their attention to detail was amazing. Great customer service. Always took care of any details that needed to be done. If I have any other window work that needs to be done I will be calling these guys.


Our Formula for Success


Let us know when we can stop by to view the space, discuss your needs, and provide you with a free quote.

Expand, intersect, pointers, screen resolution, spread


Compare available styles, designs, and functions with an experienced design consultant.


Relax knowing the installation will be quick and painless with no mess or damage left behind.

A Colorado Staple Built on a National Reputation

Year History of Replacement Experts

Successful Installations

Families Served

Customer Satisfaction Rating

Not only are we a trusted face in your community — we are the trusted partners of a national brand, Infinity(R) from Marvin(R). This window manufacturer ranks #1 in customer satisfaction for its quality and longevity and considers us Diamond-level partners in the windows industry nation wide.


We don’t hide behind a nationally accredited brand service standard — we let our service speak for itself.


If you’re looking for a local recommendation for windows, door, or siding replacement, schedule your free quote or give us a call today.

We understand that Colorado homeowners have to endure more than their fair share of extreme weather conditions.

Your home is your biggest investment. Protect this investment with products and services which have proven to outlast the competition in the harsh Colorado elements.


Hail, wind, extreme temperatures, and high altitude will take their toll on the exterior of your house from season to season which means that eventually you’ll be faced with the decision to replace or repair your windows, doors, or siding. And if you’re like most homeowners, it may be your first experience in doing so.


You deserve to work with a team that offers decades of direct insight into which brands can withstand the elements along with proven installation techniques to keep your home looking beautiful and your family feeling safe and comfortable.