A-1 Windows & Doors LLC

Quality Window & Door installation done right the first time.

Visit our gallery of windows, doors, siding and other renovations!

Visit Our Before and After Gallery Page

Make an appointment to come see our showroom, and the many samples of products offered.



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If you have a home improvement project in mind, call us today and come see the quality of the products we offer. Make an appointment to come see our showroom! We have samples of many of the windows offered in this marketplace on display, so you can make an educated decision on the products for your home.


Hours of operation are Monday - Friday 8 a.m. to 4 p.m.


Get a FREE quote TODAY!




We specialize in the installation of new construction and replacement windows. We offer many brands of vinyl, wood, and composite windows in all styles.



We install fiberglass, vinyl, wood, and composite doors and patio doors, as well as offer installation of interior & storm doors.



We install all varieties of wood and vinyl siding, offering top performing brands, styles, and colors.


Other Services


In addition to our standard services, we build decks and three-season rooms, install gutters, shutters, and offer light remodeling and finish carpentry. A wide variety of products are available in our showroom to look at and try out! Our showroom is available by appointment only, so call today! Make an appointment for a free in-home estimate.




You'll notice the difference right away!


There are many benefits in replacing the windows, doors, or siding on your home! These benefits include, but are not limited to:

  • Protection from the elements
  • Increased home value
  • Reduced maintenance
  • Enhanced look of your home
  • Increased use of space
  • More light & functionality

Hours of operation are Monday - Friday 8 a.m. to 4 p.m.


Get a FREE quote TODAY!



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     Contracting with A1 Windows & Doors, LLC was a dream come true. The moment I met with the owner, Dan, and his office Mgr., Sharon, I knew I had found the company for me. I am a retired painting contractor who was a perfectionist about my work, diligent about customer communication, use of quality products, and a WOMAN. Everyone at this company was professional, knowledgeable, and respectful, in addition to Dan, Don, and Kyle all possessing Master carpentry skills. They handled all unseen issues (there were three) with solutions communicated to me immediately (no surprises). They are a perfect team and, for me, the perfect number of people I can deal with in my home with three indoor cats. I got 24 new windows (Mercury Excelum EOS+) installed by skilled craftsmen and I never had to clean up the interior of the house, the yard, or the garage when they left everyday! As I said...A DREAM COME TRUE! So, if you don't want a nightmare, call A1 Windows & Doors, LLC.

Thank you all! The windows are beautiful, they function smoothly, no more drafts, and they are made in Connecticut!

- G. B. -

     Just want to highly recommend Dan DiMenna of A-1 Windows and Doors, LLC out of Simsbury! Had three older Mercury Excelum windows repaired and an awesome high-quality replacement storm door installed at a very reasonable price and excellent workmanship. They were on-time and great to work with. They will be replacing the front door and storm door next year for certain. Again, highly recommended!

- Dennis H -

     Daniel was wonderful. He listened to what I wanted and helped me design a storm door and front door that is perfect. Install team was great. Couldn't have asked for better customer service from start to finish.

- Nance C -

     I have an old home and a couple of weeks ago, a French door with 10 panes just crumbled in my hands when I opened it. I didn't know where to turn but I did go to a Simsbury neighbors website and saw quite a few recommendations about A-1 Windows & Doors. I called them and immediately Dan came over to evaluate my situation. A decision was made, and he came back and took the door away and I chose to repair the door to original status instead of getting a new door. I wanted to maintain the authenticity of the room with these doors. To my delight, today Dan returned my door and rehung it. It is perfect and looks exactly like it did. Problem solved and the price was reasonable. I was very impressed! Thank you A-1!

- Marisa M -

     We have had A1 perform a number of jobs at our house and are always very happy with the results. They are very professional and do great work at a reasonable price.

- Colleen D -



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NAHB Member


RRP-certified firm NAT-49554-3


We are a BBB Accredited Business with an A+ BBB Rating, in addition to being an NAHB Member, and an RRP-certified firm.