20 Best Window Companies in Killingly, CT (2025 Reviews)

Window World is the largest window replacement company in the country, known for its vinyl windows and affordability. Window World has about 27 years of experience in the industry, and it currently provides services to 200 locations nationwide.

If you’re looking for a company that is certified by the Environmental Protection Agency (EPA) and Energy Star and supports charities like St. Jude Children’s Research Hospital, Window World may be the company for you.

Its high-performance Low-E (low-emissivity) coatings and argon gas insulation offer exceptional efficiency and performance for any home. Not all of Window World’s offerings are Energy Star certified, so make sure you mention that you’re interested in Energy Star windows when inquiring.

Prices are not available on Window World’s website since the cost of window replacement differs based on how many and what type(s) of windows you need. However, it's known for offering some of the most affordable window installations around. For more detailed information on the cost, you can inquire about a quote from the company.

Renewal by Andersen is a subsidiary of the Andersen Corporation, a major manufacturer of windows and doors. Andersen has about 27 years of experience in the industry, and it currently provides services to nearly every state except Mississippi and West Virginia.

If you’re looking for a company that uses in-home estimates and advanced digital tools to help you plan and visualize your project before getting started, Andersen may be the company for you.

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. Not all of Andersen’s offerings are Energy Star certified, so make sure you mention that you’re interested in Energy Star windows when inquiring.

Prices are not available on Andersen’s website since the cost of window replacement differs based on how many and what type(s) of windows you need. However, based on customer feedback, you can expect to pay anywhere between $750 to $1,250 per window for an installation with Andersen. For more detailed information on the cost, you can inquire about a quote from the company.

Aeroseal Windows is an installer that mainly serves commercial and multifamily properties, and also specializes in railings. If you’re looking for residential window installations, you should probably refer to one of the other companies on this list. Aeroseal has about 23 years of experience in the industry, and it currently provides services to 13 states and Washington D.C.

If you’re looking for a company that installs windows and doors at businesses across the Eastern U.S, Aeroseal may be the company for you.

The company claims it helps businesses save on energy expenses and reduce their carbon footprints with energy-efficient windows, as well as practices like Low-E glass coating, weatherstripping and more. Not all of Aeroseal’s offerings are Energy Star certified, so make sure you mention that you’re interested in Energy Star windows when inquiring.

Prices are not available on Aeroseal’s website since the cost of window replacement differs based on how many and what type(s) of windows you need. However, it provides high-quality windows at a competitive price point. For more detailed information on the cost, you can inquire about a quote from the company.

Window Nation is a company that serves hundreds of thousands of homeowners, mostly in the mid-Atlantic region of the U.S. Window Nation has about 16 years of experience in the industry, and it currently provides services to residents within 75 miles of its showrooms, which are in 13 states.

If you’re looking for a company that gives customers the opportunity to view products and to speak to a representative in person in its showrooms, Window Nation may be the company for you.

Each product has windowpanes coated with a Low-E (low emissivity) glaze that prevents damaging UV rays from heating your home. Plus, the spaces between double- and triple-pane windows are filled with argon gas that’s been proven to improve home insulation. Not all of Window Nation’s offerings are Energy Star certified, so make sure you mention that you’re interested in Energy Star windows when inquiring.

Prices are not available on Window Nation’s website since the cost of window replacement differs based on how many and what type(s) of windows you need. However, based on customer feedback, you can expect to pay between $300 and $525 per window installed, making it a more affordable option compared to competitors. For more detailed information on the cost, you can inquire about a quote from the company.