20 Best Window Companies in Longmont, CO (2025 Reviews)

When the time comes to replace your windows, our list of the top window installation companies can help you find the right provider for you.

We analyzed all the top-rated window companies in Longmont and selected the best 20 based on:

  • Customer reviews
  • Window installation expertise
  • Popularity with home-owners like you
EcoWatch Local Advisors

By EcoWatch Local Advisors

Updated January 24, 2025

Why you can trust EcoWatch

Our panel of energy experts work tirelessly to create unbiased reviews and informative content to help homeowners make educated decisions. No other windows site has covered energy efficiency and sustainability as long as EcoWatch, which means we're going to help you find windows replacements that will save on your energy bill and put more money back in your wallet.

Whether you're updating for aesthetics or have windows that need repairs, windows play a crucial role in conserving your home's electricity. Damaged or outdated windows could lead to having higher electric bills during the winter or summer months.

Replacement windows improve your home’s insulation, not only making you more comfortable during extreme temperatures, but also saving you money and helping the environment.

So if you’re building a new home, renovating or replacing your windows in Longmont, you’ve found the best place to get started.

Advertisement

Best Availability

Renewal by Andersen

★★★★★
4.5
  • Great Industry Reputation
  • Award-winning Company
  • Member of US Green Building Council
  • Manufactures products in-house
Save $375 Off Each Window
Get Estimate

Best Energy-Efficient Features

Champion

★★★★★
4.5
  • Many years of experience
  • Low prices relative to competitors
  • Limetime warranty
Save 35% + $100 off per window!
Get Estimate

Power Home

★★★★★
4.5
  • Uses eco-friendly materials
  • Well-trained, certified installers
  • Lifetime or lengthy warranty
Next-Day Appointments Available
Get Estimate

Best Window Installation & Replacement Companies in Longmont

The EcoWatch Reviews team researched dozens of window providers across Longmont to narrow our list down to the top ones. The companies in this article passed our review standards for energy-efficient offerings as well as price, customer service, local expertise and beyond.

Window World logo
Best Affordability

Window World

★★★★★
BBB Rating: A+
Locations: Nationwide
Founded: 1995
Pros:
  • Pros icon EnergyStar Partner
  • Pros icon Large serice area
  • Pros icon Low prices relative to competitors
  • Pros icon Great industry reputation
  • Pros icon Lifetime warranty
Cons:
  • Pros icon Quality of service will depend on your area

Window World is the largest window replacement company in the country, known for its vinyl windows and affordability. This company has 27 years of experience in the window installation business, and it has established itself as one of the most reputable companies in Longmont.

It is certified by the Environmental Protection Agency (EPA) and Energy Star and supports charities like St. Jude Children’s Research Hospital.

Energy Efficiency of Window World Windows

There are a wide variety of window types that Window World offers, some of which are Energy Star products. Its high-performance Low-E (low-emissivity) coatings and argon gas insulation offer exceptional efficiency and performance for any home.

How much does Window World cost in Longmont?

Although pricing information is not readily available on Window World’s website, it's known for offering some of the most affordable window installations around. You can request a free quote on its website for more information about pricing.

Renewal by Andersen logo
Best Overall

Renewal by Andersen

★★★★★
BBB Rating: A
Locations: Nationwide
Founded: 1995
Pros:
  • Pros icon Great industry reputation
  • Pros icon Award-winning company
  • Pros icon Member of US Green Building Council
  • Pros icon Manufactures products in-house
Cons:
  • Pros icon No lifetime warranty
  • Pros icon More expensive than competition

Renewal by Andersen is a subsidiary of the Andersen Corporation, a major manufacturer of windows and doors. This company has 27 years of experience in the window installation business, and it has established itself as one of the most reputable companies in Longmont.

It uses in-home estimates and advanced digital tools to help you plan and visualize your project before getting started.

Energy Efficiency of Renewal by Andersen Windows

There are a wide variety of window types that Renewal by Andersen offers, some of which are Energy Star products. A handful of windows manufactured by the Andersen corporation were awarded Energy Star’s “Most Efficient” in 2021, and Andersen was named Energy Star’s Partner of the Year in 2019.

How much does Renewal by Andersen cost in Longmont?

Although pricing information is not readily available on Andersen’s website, based on customer feedback, you can expect to pay anywhere between $750 to $1,250 per window for an installation with Andersen. You can request a free quote on its website for more information about pricing.

One thing to note is that the companies in this section are national, meaning the quality of customer service may vary depending on your local team. We have tried to stay unbiased and transparent by including both pros and cons for every company.

More Window Companies in Longmont

Renewal by Andersen Window Replacement

Longmont, CO
4.8
★★★★★
  • Pros icon Price Transparency
  • Pros icon Free assessment
  • Pros icon Good Customer Service

Services Offered

  • Service icon Double-Hung
  • Service icon Vinyl Frames
  • Service icon Energy-Efficient Options
  • Service icon Metal Frames
  • Service icon Window Replacement/Installation
  • Service icon Glass Doors
  • Service icon Custom Window Designs
  • Service icon Bay Windows

Website: https://fortcollinswindow.com/
Address: 14330 Longs Peak Ct, Longmont, CO 80504
Phone: (970) 305-5060

Champion Replacement Windows of Ft. Collins

Loveland, CO
4.6
★★★★★
  • Pros icon Price you're quoted is the price you pay
  • Pros icon Good Customer Service
  • Pros icon Price Transparency
  • Pros icon Free assessment
  • Pros icon Products made in the USA
  • Pros icon ENERGY STAR® certified

Services Offered

  • Service icon Glass Doors
  • Service icon Double-Hung
  • Service icon Window Replacement/Installation
  • Service icon Bay Windows

Website: https://www.championwindow.com/Ft-Collins/
Address: 5850 Byrd Dr, Loveland, CO 80538
Phone: (970) 744-2604

Champion Replacement Windows of Denver

Denver, CO
4.4
★★★★★
  • Pros icon Price Transparency
  • Pros icon Free assessment
  • Pros icon Good Customer Service

Services Offered

  • Service icon Window Replacement/Installation
  • Service icon Double-Hung
  • Service icon Glass Doors
  • Service icon Bay Windows

Website: https://www.championwindow.com/Denver/
Address: 10035 E 40th Ave Suite 400, Denver, CO 80238
Phone: (303) 800-2129

Power Home Remodeling

Centennial, CO
4.4
★★★★★
  • Pros icon Good Customer Service
  • Pros icon Price Transparency
  • Pros icon Free assessment
  • Pros icon Timely Service

Services Offered

  • Service icon Energy-Efficient Options
  • Service icon Window Replacement/Installation

Website: https://powerhrg.com/
Address: 7304 S Joliet St #100, Centennial, CO 80112
Phone: (303) 357-2484

DaBella

Denver, CO
4.4
★★★★★
  • Pros icon Wide range of styles
  • Pros icon Customized to your home
  • Pros icon Good Customer Service
  • Pros icon Timely Service
  • Pros icon Triple-pane vinyl windows

Services Offered

  • Service icon Vinyl Frames
  • Service icon Glass Doors
  • Service icon Double-Hung
  • Service icon Window Replacement/Installation

Website: https://dabella.us/location/colorado/
Address: 6600 E Hampden Ave, Denver, CO 80224
Phone: (720) 619-8704

Window Nation

Aurora, CO
4.3
★★★★★
  • Pros icon Educational Website
  • Pros icon Price Transparency
  • Pros icon Free assessment
  • Pros icon Good Customer Service

Services Offered

  • Service icon Double-Hung
  • Service icon Custom Window Designs
  • Service icon Window Replacement/Installation
  • Service icon Bay Windows
  • Service icon Energy-Efficient Options
  • Service icon Glass Doors

Website: https://www.windownation.com/denver-window-replacement/
Address: 2450 Airport Blvd, Aurora, CO 80011
Phone: (720) 409-0170

Custom Exteriors

Berthoud, CO
5.0
★★★★★
  • Pros icon Good Customer Service
  • Pros icon Price Transparency
  • Pros icon Educational Website
  • Pros icon Free assessment
  • Pros icon Timely Service

Services Offered

  • Service icon Window Replacement/Installation
  • Service icon Bay Windows
  • Service icon Vinyl Frames
  • Service icon Glass Doors

Website: https://customexteriorsllc.com/
Address: 18674 Co Rd 3, Berthoud, CO 80513
Phone: (970) 460-8714

Loveland Window Cleaning Services

Loveland, CO
5.0
★★★★★
  • Pros icon Free assessment
  • Pros icon Good Customer Service

Services Offered

  • Service icon Energy-Efficient Options
  • Service icon Window Replacement/Installation

Website: http://www.lovelandwindowcleaningservices.com/
Address: 1083 Winona Dr, Loveland, CO 80537
Phone: (970) 541-3787

DMD Window & Door

Wheat Ridge, CO
5.0
★★★★★
  • Pros icon Good Customer Service
  • Pros icon Timely Service
  • Pros icon Free assessment
  • Pros icon Price Transparency

Services Offered

  • Service icon Vinyl Frames
  • Service icon Glass Doors
  • Service icon Custom Window Designs
  • Service icon Energy-Efficient Options
  • Service icon Window Replacement/Installation
  • Service icon Wood Frames

Website: https://www.dmdbuilders.com/
Address: 4251 Kipling St #190, Wheat Ridge, CO 80033
Phone: (303) 757-2721

Powerhouse Roofing and Exteriors

Greeley, CO
5.0
★★★★★
  • Pros icon Price Transparency
  • Pros icon Free assessment
  • Pros icon Educational Website
  • Pros icon Good Customer Service

Services Offered

  • Service icon Window Replacement/Installation

Website: http://powerhouseroofingco.com/
Address: 1907 1st Ave, Greeley, CO 80631
Phone: (970) 324-7651

AllGuard Windows and Doors Fort Collins

Fort Collins, CO
5.0
★★★★★
  • Pros icon Good Customer Service
  • Pros icon Price Transparency
  • Pros icon Free assessment

Services Offered

  • Service icon Window Replacement/Installation
  • Service icon Double-Hung
  • Service icon Glass Doors
  • Service icon Energy-Efficient Options
  • Service icon Wood Frames
  • Service icon Metal Frames
  • Service icon Fiberglass Frames
  • Service icon Vinyl Frames

Website: https://allguardwindows.com/
Address: 456 S Link Ln, Fort Collins, CO 80524
Phone: (970) 481-5907

Bright Idea Egress — Window Kits

Sheridan, CO
5.0
★★★★★
  • Pros icon Timely Service
  • Pros icon Educational Website
  • Pros icon Good Customer Service
  • Pros icon Free assessment
  • Pros icon Price Transparency

Services Offered

  • Service icon Wood Frames
  • Service icon Window Replacement/Installation
  • Service icon Metal Frames

Website: https://brightideaegress.com/
Address: 3971 S Decatur St Unit C, Sheridan, CO 80110
Phone: (303) 761-3730

Storm Exteriors

Centennial, CO
5.0
★★★★★
  • Pros icon Timely Service
  • Pros icon Free assessment
  • Pros icon Good Customer Service
  • Pros icon Educational Website
  • Pros icon Price Transparency

Services Offered

  • Service icon Window Replacement/Installation

Website: http://www.stormexteriors.com/
Address: 7853 E Arapahoe Ct #3100, Centennial, CO 80112
Phone: (720) 900-1316

United Windows Pro - Windows and glass repair

Aurora, CO
5.0
★★★★★
  • Pros icon Fast emergency response
  • Pros icon Educational Website
  • Pros icon Timely Service
  • Pros icon Free assessment
  • Pros icon Good Customer Service
  • Pros icon Commercial and residential
  • Pros icon Financing options available
  • Pros icon Price Transparency

Services Offered

  • Service icon Window Repair
  • Service icon Tempered Glass
  • Service icon Triple Pane Glass
  • Service icon Window Replacement/Installation
  • Service icon Glass Repair
  • Service icon Wood Frames
  • Service icon Glass Doors
  • Service icon Energy-Efficient Options

Website: https://www.unitedwindowspro.com/
Address: 4515 S Nepal Ct, Aurora, CO 80015
Phone: (720) 400-2929

Colorado Windows and Restoration

Highlands Ranch, CO
5.0
★★★★★
  • Pros icon Timely Service
  • Pros icon Good Customer Service
  • Pros icon Free assessment
  • Pros icon Price Transparency

Services Offered

  • Service icon Window Replacement/Installation
  • Service icon Glass Doors
  • Service icon Double-Hung

Website: http://www.coloradowr.com/
Address: 9609 S University Blvd #630414, Highlands Ranch, CO 80130
Phone: (303) 953-0691

All-Star Construction Windows & Doors

Parker, CO
5.0
★★★★★
  • Pros icon Educational Website
  • Pros icon Free assessment
  • Pros icon Good Customer Service

Services Offered

  • Service icon Mirrors
  • Service icon Glass Showers
  • Service icon Glass Repair
  • Service icon Energy-Efficient Options
  • Service icon Vinyl Frames
  • Service icon Window Replacement/Installation

Website: http://www.allstarconstruction.org/
Address: 515 Singing Hills Rd Unit 104, Parker, CO 80138
Phone: (303) 646-3018

WestPro | Roofing, Siding, Windows

Longmont, CO
4.9
★★★★★
  • Pros icon Free assessment
  • Pros icon Good Customer Service
  • Pros icon Educational Website
  • Pros icon Price Transparency

Services Offered

  • Service icon Skylights
  • Service icon Window Replacement/Installation
  • Service icon Glass Doors
  • Service icon Storm/Impact Windows

Website: https://westproroofing.com/
Address: 1321 Sherman Dr, Longmont, CO 80501
Phone: (303) 834-9236

Rocky Mountain Glass & Shower LLC

Longmont, CO
4.9
★★★★★
  • Pros icon Price Transparency
  • Pros icon Good Customer Service
  • Pros icon Free assessment
  • Pros icon Educational Website

Services Offered

  • Service icon Tempered Glass
  • Service icon Energy-Efficient Options
  • Service icon Glass Doors
  • Service icon Window Replacement/Installation
  • Service icon Mirrors
  • Service icon Glass Showers
  • Service icon Window Repair

Website: http://www.rmglass.com/
Address: 13631 N 115th St, Longmont, CO 80504
Phone: (970) 347-9710

BlueBird Windows & Doors

Lafayette, CO
4.9
★★★★★
  • Pros icon Good Customer Service
  • Pros icon Free assessment
  • Pros icon Price Transparency
  • Pros icon Educational Website

Services Offered

  • Service icon Window Replacement/Installation
  • Service icon Double-Hung
  • Service icon Glass Doors
  • Service icon Energy-Efficient Options
  • Service icon Bay Windows

Website: https://www.gobluebirdco.com/
Address: 1200 Diamond Cir Unit J, Lafayette, CO 80026
Phone: (303) 810-2888

Slade Glass Co.

Boulder, CO
4.9
★★★★★
  • Pros icon Price Transparency
  • Pros icon Educational Website
  • Pros icon Free assessment
  • Pros icon Good Customer Service

Services Offered

  • Service icon Mirrors
  • Service icon Glass Repair
  • Service icon Glass Showers
  • Service icon Window Replacement/Installation

Website: http://sladeglass.com/
Address: 1770 38th St, Boulder, CO 80301
Phone: (303) 276-1550
Longmont Window Cost Calculator

Calculate how much you can expect to pay for window installation and replacement in Longmont, CO using our customized window cost calculator.

Estimated Window Cost:
161 homeowners have requested a free estimate in the last 3 days.

Estimates will vary based on window dimensions and other unique factors to your home. Getting in touch with a local window installer is the best way to get an accurate cost estimate for your home.

How Installing Energy-Efficient Windows in Longmont Saves You Money

Upgrading to energy-efficient windows can improve the comfort of your home and help you save on electricity bills. Here are more details about how upgrading your windows could help you:

  • Decrease your carbon footprint: In Longmont, you can reduce your indirect greenhouse gas emissions by about 460 pounds per year once you switch to energy-efficient windows.
  • Save on electricity bills: Since energy-efficient windows decrease the amount of energy used to heat or cool your home, the switch can help you save about $449 annually on your energy bills in Longmont.
  • Protect your investment: When your home is on the older side, your windows could also be outdated or damaged. Upgrading and repairing your windows is an important part of maintaining your property and its value.
  • Protect your valuables: Many Energy Star certified windows have low-emissivity coatings, which not only provide better insulation for your home, but also filter out damaging UV rays, preventing fading of your furniture, carpet and other valuables.

Estimated Cost of Window Replacement in Longmont

Windows come in all shapes and sizes, so costs and services will differ remarkably. Here are the average costs and services that you can find from window installation companies.

How Much Do New Windows Cost?

According to our market research, the average cost to replace a single window is about $600. However, window installation costs can range from $200 to $1,200 per window. But prices vary remarkably depending on the size of your home, complexity of the installation, your location and the quality of the company you choose. Many window companies also provide door installations, which carry a higher price tag.

Keep in mind that energy-efficient windows may come at a higher price point, but Energy Star estimates the upgrade will save you between $101 and $583 per year when you replace single-pane windows and between $27 and $197 per year when you install double-pane, clear glass windows. Your savings will vary based on your local climate, energy rates and individual home characteristics.

The cost of your window installation will also vary depending on the kind of material you choose for the frames. Wood windows are generally the most expensive, but it depends on whether they are solid wood or clad with aluminum or vinyl. Fiberglass windows also tend to be somewhat more expensive than vinyl, but they are more efficient.

What Services do Window Installers Offer?

In regard to window replacements, there are generally two kinds that your provider will offer: full-frame and pocket installations.

Full-frame installations are necessary when you want a new style or your window has significant deterioration. With this service, your installers will replace the whole window, including the frame, trim and sill. Pocket installations are on the simpler end and won’t carry as large a bill, as they involve simply replacing the window within its existing frame. But if the frame has any damage or rot, you may have to get a full-frame installation instead.

If you’re hiring a reputable window installation company, your company will be able to advise you on the best type for your project. In Longmont, the choice will mostly be influenced by the efficiency of your home and how old your existing frames are.

Advertisement

Best Availability

Renewal by Andersen

★★★★★
4.5
  • Great Industry Reputation
  • Award-winning Company
  • Member of US Green Building Council
  • Manufactures products in-house
Save $375 Off Each Window
Get Estimate

Best Energy-Efficient Features

Champion

★★★★★
4.5
  • Many years of experience
  • Low prices relative to competitors
  • Limetime warranty
Save 35% + $100 off per window!
Get Estimate

Power Home

★★★★★
4.5
  • Uses eco-friendly materials
  • Well-trained, certified installers
  • Lifetime or lengthy warranty
Next-Day Appointments Available
Get Estimate

How We Choose the Best Window Installers in Longmont

In our hunt to make your home improvements easier and more eco-friendly in Longmont, EcoWatch evaluated many companies before landing on these. We’ve decided to review the best window installers in Longmont primarily based on energy efficiency, as it’s what’s best for the environment and for you as a homeowner. Energy Star certified windows can reduce your energy bills by hundreds of dollars. Along with energy efficiency, our rating methodology considers the following factors:

Service Area

This one is pretty self-explanatory, but we’ve chosen to highlight window installers that serve Longmont so you can find the best window installation company near you.

Work Quality

We’re willing to bet that you’re not looking for a company to do a shoddy job installing windows. We’ve vetted each company in our guide to make sure its contractors are well-qualified and that the company has received tons of positive customer feedback to vouch for its service.

Customer Reviews

Another self-explanatory yet very important review factor is customer feedback. If the majority of customers don’t have positive feedback about their service from a certain company, you won’t see it featured on EcoWatch.

Cost

This one is a give-and-take: similar to other services, cheap window installers may not provide the highest quality service. On the other hand, we want to ensure we’re highlighting companies that offer a range of price and financing options so they’re accessible to most homeowners.

Warranty

As discussed previously, windows are a serious investment, so you’ll want to make sure that investment is protected. Window installation companies that have lengthy warranties for products, parts and installation (aka workmanship) rank higher with EcoWatch.

Years of Experience

Due to Longmont’s climate, homeowners need to be wary of rot, low efficiency and water damage. We factored in local experience to reflect the ability of Longmont window companies to prepare homes for the climate. If a company has less than 10 years of experience, it loses points in this category.

Longmont, CO Window Replacement FAQs

How much does a window install cost?

The national average cost of replacing a window is about $600 but can range between $200 and $1,200, depending on a few different factors. The price is typically influenced by the type and material of the window, the location of your property and the size of the window. Also, bear in mind that energy-efficient windows may cost more upfront but can save you hundreds of dollars a year in energy bills.

What are the most common kinds of replacement windows?

The most common kinds of windows for homes include: picture windows, transom windows, slider windows, awning windows, double-hung and single-hung windows, casement windows and bay windows.

When do I have to use a window installation company?

You should use a window installation professional whenever you need to upgrade your windows. Installing windows is a involved process that can take a lot of time, so it’s best handled by the professionals.

What time of year is a good time to replace my windows?

Replacement windows can be installed at any time, but autumn might be the best season. Regardless of when you install them, the contractors will take steps to make sure that too much hot or cold air doesn’t get into your house, so the temperature outside isn’t necessarily a big factor. What’s more important than the temperature is that the weather should be dry.

Should I replace my windows all at the same time?

If you want to get more efficient windows and save money on energy costs, replacing all of your windows at the same time is the only way to see a noticeable difference. On the other hand, if you have just one or two windows that are damaged or drafty, you can replace just those.