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Best Window Replacement Companies in Thornton, CO

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Written By Max Peterson|Last Updated: February 05, 2024

Replacement windows can protect your home from leaks and drafts, increase its energy efficiency, and give it some additional aesthetic appeal. A skilled window company can help you get the most value from your replacement windows, so you can maximize their lifespan.

Top Pick
  • Full-service installation
  • Large window selection
  • Nearly 30 years of experience
Best Financing
  • Full-service installation
  • In-house, U.S.-made products
  • More than 70 years of experience
Most Customizable
  • Full-service remodeling
  • 96% satisfaction rate
  • More than 30 years of experience

Top 10 Thornton Window Installation Companies

We recommend these local contractors for your window replacement in Thornton.

Thornton residents can trust the This Old House Reviews Team to provide relevant and up-to-date window company recommendations in their area. To determine which installers are the best, we focus on these five criteria:

  • Services and warranties
  • Product quality
  • Energy-efficiency guarantees
  • Professional experience and licensure
  • Customer reviews and recommendations
Champion Replacement Windows of Denver Logo

Champion Replacement Windows of Denver

Based on 1,557 customer reviews.

Services Offered

Window Replacement/installationBay WindowsGlass DoorsDouble-Hung


  • Good customer service
  • Free assessment
  • Price transparency
10035 E 40th Ave Suite 400, Denver, CO 303-800-2129 championwindow.com
Champion Replacement Windows of Ft. Collins Logo

Champion Replacement Windows of Ft. Collins

Based on 777 customer reviews.

Services Offered

Glass DoorsBay WindowsDouble-HungWindow Replacement/installation


  • Free assessment
  • Price transparency
  • Good customer service
5850 Byrd Dr, Loveland, CO 970-744-2604 championwindow.com
Power Home Remodeling Logo

Power Home Remodeling

Based on 2,686 customer reviews.

Services Offered

Energy-Efficient OptionsWindow Replacement/installation


  • Good customer service
7304 S Joliet St #100, Centennial, CO 303-357-2484 powerhrg.com
Window World of Denver Logo

Window World of Denver

Based on 342 customer reviews.

Services Offered

Double-HungBay WindowsWindow Replacement/installationEnergy-Efficient OptionsCustom Window DesignsTriple Pane GlassGlass Doors


  • Price transparency
  • Educational website
  • Timely service
480 E 76th Ave Bldg 5e, Denver, CO 303-574-9594 windowworldcolorado.com
DaBella Logo


Based on 844 customer reviews.

Services Offered

Window Replacement/installationDouble-HungGlass DoorsVinyl Frames


  • Good customer service
  • Timely service
6600 E Hampden Ave, Denver, CO 720-619-8704 dabella.us
True View Windows & Glass Logo

True View Windows & Glass

Based on 345 customer reviews.

Services Offered

Window RepairMirrorsWindow Replacement/installationTempered GlassGlass DoorsGlass Showers


  • Free assessment
  • Good customer service
  • Price transparency
3200 W 71st Ave #20, Westminster, CO 720-431-8783 trueviewglass.com
K&G Window Pros Logo

K&G Window Pros

Based on 352 customer reviews.

Services Offered

Window Replacement/installationGlass Doors


  • Good customer service
  • Free assessment
  • Educational website
203 Telluride St Suite 850, Brighton, CO 720-328-2786 kgwindowpros.com
Lifetime Windows & Siding Logo

Lifetime Windows & Siding

Based on 1,039 customer reviews.

Services Offered

Glass ShowersFiberglass FramesGlass DoorsEnergy-Efficient OptionsCustom Window DesignsDouble-HungWindow Replacement/installation


  • Free assessment
  • Educational website
  • Price transparency
9525 E 40th Ave Unit 160a, Denver, CO 303-536-8809 lifetimewindows.com
BlueBird Windows & Doors Logo

BlueBird Windows & Doors

Based on 294 customer reviews.

Services Offered

Energy-Efficient OptionsWindow Replacement/installationGlass DoorsBay WindowsDouble-Hung


  • Free assessment
  • Price transparency
  • Educational website
1200 Diamond Cir Unit J, Lafayette, CO 303-810-2888 gobluebirdco.com

More Local Window Companies

Colorado Glass and Mirror LLC

User Reviews: 4.6/5 

1400 W 70th Ave
Denver, CO 80221

Smart Windows

User Reviews: 4.6/5 

740 S Pierce Ave # 5
Louisville, CO 80027

KV Windows Inc.

User Reviews: 4.5/5 

3660 W 73rd Ave
Westminster, CO 80030

Carlson Siding & Construction

User Reviews: 4.5/5 

13395 Olive St
Thornton, CO 80602

New Windows for America

User Reviews: 4.5/5 

33 N Main St
Brighton, CO 80601

Colorado Classic Exteriors: Windows, Doors, Pergolas

User Reviews: 4.5/5 

7985 Vance Dr #202
Arvada, CO 80003

To share feedback or ask a question about this article, send a note to our Reviews Team at reviewsteam@thisoldhousereviews.com.

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Facts about Thornton
Annual Energy Efficient Windows Savings:$455
Average Max Temp:63°F
Average Min Temp:43°F
Average Daily Sunlight:61%
Average Annual Snowfall:55.3"
Average Monthly Precipitation:1.25"

Expert Tips By

This Old House empowers homeowners with the knowledge and tools they need to tackle various projects and navigate the complexities of homeownership.

How To Choose a Window Company in Thornton

With Thornton's large population, you're sure to find a reputable window company that aligns with your values and preferences. As you reach out to companies, keep the following factors in mind:

Window Cost by Type

When you're shopping for new windows, it's important to remember that there's more to cost than just purchase price. You want a window with top-notch quality and durability. Choosing economy windows could actually increase your overall cost, due to their shorter lifespan and more intensive maintenance needs. The age of your home, together with the sizes, materials, and styles of windows you select, can affect pricing. Single-hung windows often cost less due to their straightforward style and simple mechanisms, while new skylights cost more to prepare for and install. A professional can guide you through selecting the products that fit your needs.

In this table, you can find cost data for the most common residential window types to determine how much you might pay.

Window TypesAverage Cost
Glass Block$44-$565

Window Material Cost

Materials also help determine a window's cost. You might select a material based on the local climate, your desired look, and your energy efficiency goals. For example, wood windows can give your home an organic design without breaking the bank, but you'll have to invest more toward maintenance. Aluminum and composite windows cost more up-front, but they're incredibly durable against the elements, so you'll spend far less on maintenance.

Window TypesAverage Cost

Other Window Replacement Costs

Your total cost for new windows will also include applicable warranty fees, permit application fees, and labor. Ensure that you discuss each of these elements with a sales representative before committing to a window company.

Experience and Training

Select a company that focuses on window repair and installation, and look for this information on its website:

  • How long it's been serving the Thornton area
  • Photo galleries of completed projects
  • Private credentials attesting to its workmanship
The more experience a company has, the better its service and workmanship.

Licensing and Credentials

Colorado's contractor licensing requirements are distinct compared to many states. There is no central board that licenses window companies, but they might still need licenses from local authorities in which they operate. Colorado Springs and Denver license window installers, treating them as either general contractors or building contractors. For other areas, contact your local authorities.

Types of Windows Offered

No two companies offer the same window designs and materials. Find one that's an expert in the type you want for your home.

  • Awning
  • Bay
  • Bow
  • Casement
  • Crank-out
  • Custom
  • Double- or single-hung
  • Egress
  • Garden
  • Jalousie
  • Picture
  • Sliding
  • Skylight
  • Specialty
  • Storm
  • Transom
  • Vent
Equally important to your desired windows' shape is their framing. Ask your window provider if it offers the frame material you want, such as fiberglass, vinyl, composite, wood, or aluminum.

Customer Feedback

One of the greatest ways to vet a company is to see what other customers have said about their experiences. Trustworthy sources for customer reviews include Trustpilot, the BBB, and Google Speak with people you know who have used a company you're interested in, and ask a representative for a copy of its reference list.

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Frequently Asked Questions About Window Replacement in Thornton

Why should I hire a professional to install or replace my windows?

By working with a professional, you don't need to worry about making measurement mistakes or lacking the right tools. A window installation crew is well-equipped with the right supplies and knowledge to do the job safely and precisely. You can also get fast, informed answers to your questions and customized help to make the most of your new windows

Are there tax incentives for installing energy-efficient windows?

Yes. No matter where you're located, you can claim a federal tax credit of up to $3,200 per year on up to 30% of your window replacement's cost. Further, most state and some local governments offer tax breaks of their own. We recommend contacting your local tax authority for specific information about tax incentives available in your area.

How can I gauge the quality of a replacement window?

One of the first metrics you'll see when looking at a replacement window is its U-factor. The lower this number, the better the window is at blocking extreme cold and heat from entering your home. Other numbers to consider include:
  • "visible transmittance," which indicates how much light enters through the window
  • "solar heat gain coefficient," which shows how much UV light the window absorbs and releases as heat
  • "Condensation resistance," which shows how well a window can resist moisture (the higher the number, the better)
  • "Air leakage," which evaluates how easy it is for air drafts to occur (the lower the number, the better)

To share feedback or ask a question about this article, send a note to our Reviews Team at reviewsteam@thisoldhousereviews.com.

More Window Resources

National Windows Company Ranking Methodology


Energy Star