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
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Why you can trust EcoWatch
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 Damaged or outdated windows could lead to having higher electric bills during the winter or summer months.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.
Best Availability
Renewal by Andersen
- Great Industry Reputation
- Award-winning Company
- Member of US Green Building Council
- Manufactures products in-house
Best Energy-Efficient Features
Champion
- Many years of experience
- Low prices relative to competitors
- Limetime warranty
Power Home
- Uses eco-friendly materials
- Well-trained, certified installers
- Lifetime or lengthy warranty
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
EnergyStar Partner
Large serice area
Low prices relative to competitors
Great industry reputation
Lifetime warranty
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 WindowsThere 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
Great industry reputation
Award-winning company
Member of US Green Building Council
Manufactures products in-house
No lifetime warranty
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 WindowsThere 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, COPrice Transparency
Free assessment
Good Customer Service
Services Offered
Double-Hung
Vinyl Frames
Energy-Efficient Options
Metal Frames
Window Replacement/Installation
Glass Doors
Custom Window Designs
Bay Windows
Champion Replacement Windows of Ft. Collins
Loveland, COPrice you're quoted is the price you pay
Good Customer Service
Price Transparency
Free assessment
Products made in the USA
ENERGY STAR® certified
Services Offered
Glass Doors
Double-Hung
Window Replacement/Installation
Bay Windows
Champion Replacement Windows of Denver
Denver, COPrice Transparency
Free assessment
Good Customer Service
Services Offered
Window Replacement/Installation
Double-Hung
Glass Doors
Bay Windows
Power Home Remodeling
Centennial, COGood Customer Service
Price Transparency
Free assessment
Timely Service
Services Offered
Energy-Efficient Options
Window Replacement/Installation
DaBella
Denver, COWide range of styles
Customized to your home
Good Customer Service
Timely Service
Triple-pane vinyl windows
Services Offered
Vinyl Frames
Glass Doors
Double-Hung
Window Replacement/Installation
Window Nation
Aurora, COEducational Website
Price Transparency
Free assessment
Good Customer Service
Services Offered
Double-Hung
Custom Window Designs
Window Replacement/Installation
Bay Windows
Energy-Efficient Options
Glass Doors
Custom Exteriors
Berthoud, COGood Customer Service
Price Transparency
Educational Website
Free assessment
Timely Service
Services Offered
Window Replacement/Installation
Bay Windows
Vinyl Frames
Glass Doors
Loveland Window Cleaning Services
Loveland, COFree assessment
Good Customer Service
Services Offered
Energy-Efficient Options
Window Replacement/Installation
DMD Window & Door
Wheat Ridge, COGood Customer Service
Timely Service
Free assessment
Price Transparency
Services Offered
Vinyl Frames
Glass Doors
Custom Window Designs
Energy-Efficient Options
Window Replacement/Installation
Wood Frames
Powerhouse Roofing and Exteriors
Greeley, COPrice Transparency
Free assessment
Educational Website
Good Customer Service
Services Offered
Window Replacement/Installation
AllGuard Windows and Doors Fort Collins
Fort Collins, COGood Customer Service
Price Transparency
Free assessment
Services Offered
Window Replacement/Installation
Double-Hung
Glass Doors
Energy-Efficient Options
Wood Frames
Metal Frames
Fiberglass Frames
Vinyl Frames
Bright Idea Egress — Window Kits
Sheridan, COTimely Service
Educational Website
Good Customer Service
Free assessment
Price Transparency
Services Offered
Wood Frames
Window Replacement/Installation
Metal Frames
Storm Exteriors
Centennial, COTimely Service
Free assessment
Good Customer Service
Educational Website
Price Transparency
Services Offered
Window Replacement/Installation
United Windows Pro - Windows and glass repair
Aurora, COFast emergency response
Educational Website
Timely Service
Free assessment
Good Customer Service
Commercial and residential
Financing options available
Price Transparency
Services Offered
Window Repair
Tempered Glass
Triple Pane Glass
Window Replacement/Installation
Glass Repair
Wood Frames
Glass Doors
Energy-Efficient Options
Colorado Windows and Restoration
Highlands Ranch, COTimely Service
Good Customer Service
Free assessment
Price Transparency
Services Offered
Window Replacement/Installation
Glass Doors
Double-Hung
All-Star Construction Windows & Doors
Parker, COEducational Website
Free assessment
Good Customer Service
Services Offered
Mirrors
Glass Showers
Glass Repair
Energy-Efficient Options
Vinyl Frames
Window Replacement/Installation
WestPro | Roofing, Siding, Windows
Longmont, COFree assessment
Good Customer Service
Educational Website
Price Transparency
Services Offered
Skylights
Window Replacement/Installation
Glass Doors
Storm/Impact Windows
Rocky Mountain Glass & Shower LLC
Longmont, COPrice Transparency
Good Customer Service
Free assessment
Educational Website
Services Offered
Tempered Glass
Energy-Efficient Options
Glass Doors
Window Replacement/Installation
Mirrors
Glass Showers
Window Repair
BlueBird Windows & Doors
Lafayette, COGood Customer Service
Free assessment
Price Transparency
Educational Website
Services Offered
Window Replacement/Installation
Double-Hung
Glass Doors
Energy-Efficient Options
Bay Windows
Slade Glass Co.
Boulder, COPrice Transparency
Educational Website
Free assessment
Good Customer Service
Services Offered
Mirrors
Glass Repair
Glass Showers
Window Replacement/Installation
Calculate how much you can expect to pay for window installation and replacement in Longmont, CO using our customized window cost calculator.
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.
Best Availability
Renewal by Andersen
- Great Industry Reputation
- Award-winning Company
- Member of US Green Building Council
- Manufactures products in-house
Best Energy-Efficient Features
Champion
- Many years of experience
- Low prices relative to competitors
- Limetime warranty
Power Home
- Uses eco-friendly materials
- Well-trained, certified installers
- Lifetime or lengthy warranty
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.