Why Choose Nex-Gen?

Local Service

You deserve to work with a team who can predict the unique challenges you might face before the renovation starts. In Colorado, those challenges can be extensive.


We know Colorado. That’s why we’ve specifically curated our windows, doors, siding, and installation techniques to withstand the harsh Colorado weather and the harsh UV rays, temperature fluctuations, and hail damage that come along with it. 


Since our founding in 2000, our top priority has been to provide the best for our customers. This standard for superior customer service is the cornerstone of what we do and is why we have earned a 94% customer satisfaction rating. 


Simply put — we are more than a business — we are a family. By choosing Nex-Gen, you become a part of the family as well.

Nationally Branded Products

We believe in the products and the techniques we use to install your doors and windows — so much so that we offer a warranty that extends well beyond the standard manufacturer warranty that comes with any of the products we have available.


With the Nex-Gen Peace of Mind Warranty, all future maintenance and repairs are 100% covered for as long as you own your house, no questions asked.

Our Promise to You

Transparent Interactions

We don’t believe in scare tactics or hidden fees. You’ll receive a detailed proposal with no hidden costs, no disclaimers, and best of all, no surprises.

Specialized Knowledge

40 years in the industry guarantees we’ve dealt with every imaginable scenario. Above all, we’re problem solvers who pair your unique issue with the best solution for your home.

Progressive Attitude

Our name reflects our commitment to forward thinking, innovative products, and solutions. We’re invested in creating a customer experience unparalleled in the home remodeling industry.

Specialized Knowledge

We don’t leave room for surprises. We share our process upfront, then deliver on our promise. The job doesn’t end until you’re completely satisfied with the results.

Meet the Nex-Gen Family

Brent Rajewski, owner and president of Nex-Gen Windows and Doors, was quite literally born into the home renovation industry.

His father, Ted Rajewski, trained him at an early age in the most effective techniques for installing replacement doors and windows. Over the years, Brent became an integral part of the family business and realized first hand the importance of working one-on-one with customers to earn their trust and provide only the best products available on the market.

Nex-Gen was officially launched in 2007 and quickly earned a reputation for being the most trustworthy window replacement company in northern Colorado. Today, Brent is proud to serve not only northern Colorado but every city along the front range with two showrooms located in Fort Collins and Colorado Springs.

Brent maintained the family focus of his business by building a team who would honor his mission to exceed customer expectations with superior products and a satisfying remodel experience from start to finish.

The company's rapid growth is largely due to Brent's commitment to excellence and a refusal to take shortcuts which could undermine the trust of his customers. His decision to partner with Marvin Windows, one of the best manufacturers available, and his installation methods have made Nex-Gen the preferred provider in Colorado.

We pride ourselves in providing superior products and a satisfying customer experience.

If you’re looking for new windows, doors, or siding, we would love to help. We partner with homeowners in Colorado’s Front Range, southern Wyoming, and the Colorado Springs area. We’re here to help you create a comfortable and stylish home while increasing the value of your investment. Click below to book your free design consultation below.