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When you buy new windows and doors form Big L, you can rest easy knowing our work and products are backed by our Total Trust Guarantee.

2019 BNBEA Business Ethics Award Winner

Big L is honored to be the winner of the 2019 Buffalo Niagara Business Ethics Award, in the mid-sized company category.

Hassle-Free Financing Options

We make it easy to realize your dreams today! Big L offers a variety of great financing options including "same as cash" financing with no interest and no payments for one year.


Best home window replacement company in Buffalo and Western New York

Big L Windows & Doors in greater Buffalo, NY offers home window replacement & replacement doors featuring Marvin windows for homeowners & builders. Our extensive selection of cutting edge products deliver unmatched beauty and state-of-the-art performance for energy savings, reduced maintenance and a more comfortable home.

Big L Windows & Doors delivers a wide array of custom-made styles, decorative options, complementary trim selections, and performance packages for a fully customizable solution to suit your individual needs.

We have a reputation for making a Big difference – a Big difference in sales, service, installation, and products.

Our professional approach, highly trained staff, and affordable pricing will help take the stress and confusion out of your new project.

View our window and door products and professional services.

News and Events

All About Patio Door Replacement

Patio doors are one of the most important, yet understated, features of any home. If you are looking for ways to improve access to your backyard or balcony or if you want to allow for more natural light within your...

Bay Windows Vs Bow Windows

Bay windows vs bow windows, which are better? There are many reasons to consider upgrading your home to include a new set of projection windows or replacement bay windows. Perhaps you are looking to expand your...