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Serving the Golden Horseshoe for 40 years, the secret to our success is really no secret at all – we take great pride in our quality, service, installations and our people. “Everyone at QSI is committed to the best window and door installation experience possible and this has been our guiding principle since 1976.”

Rely on QSI for best performance windows and doors. Featuring the latest in advanced technology, all of our windows are ENERGY STAR® certified, and most of them actually meet the 2020 Most Efficient designation!

At QSI, we’re your local experts for high-end windows and doors in Hamilton and the Golden Horseshoe, including: Oakville, Burlington, Niagara, Grimsby, Cambridge, Kitchener, St. Catharines, Halton & all surrounding municipalities. We proudly feature all our quality products on display in full scale, just how they would be installed on your own home. Visit our newly renovated 6,000 sq ft showroom in the Hamilton Mountain Industrial Park, at the top of the Red Hill Valley Parkway. It’s worth the drive to Hamilton! Book your free in-home consultation or come visit our showroom at 175 Nebo Rd. Hamilton, Ontario.

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Schedule your free in-home, no-obligation quote today.

All QSI window styles from fixed, sliding to casement are designed using QSI SMARTComfort technology, far exceeding Energy Star requirements today. Our range of options can be customized for design and budget, giving you three different quality levels all within the same manufactured product line.


Enhance your curb appeal and add value to your home with a custom designed entrance door manufactured using insulated steel or wood grain fibreglass panels. French design swinging or sliding patio doors in two, three and four panels enhancing your view, enjoying the outdoors in complete comfort.


All QSI window styles from fixed, sliding to casement are designed using QSI SMARTComfort technology, far exceeding Energy Star requirements today. Our range of options can be customized for design and budget, giving you three different quality levels all within the same manufactured product line.


Enhance your curb appeal and add value to your home with a custom designed entrance door manufactured using insulated steel or wood grain fibreglass panels. French design swinging or sliding patio doors in two, three and four panels enhancing your view, enjoying the outdoors in complete comfort.


Bring the outdoors indoors! Everyone wants a sunroom so they can enjoy their back yard year round in all kinds of weather. After a good days work, relax and unwind in what becomes everyone’s favorite room in the house, your QSI sunroom.


Increase the comfort of your back yard patio or deck with an attractive and stylish retractable patio awning or unobstruct your view with retractable screen doors.

QSI Is Proud to Service the Following Areas

Experience the difference QSI SmartComfort Home Products make.

  • We are completely satisfied with the installation, quality of the product (front door) and follow up service. We had a minor flaw in the glass and the service department promptly addressed the issue and replaced the glass insert. QSI gets top marks for standing by their products.Tom, Hamilton
  • QSI did work at my grand parents house years ago. Had them do our upstairs windows. Great workmanship, quality and service. The new windows are much quieter since we do back on to a busy road. Also notice them to offer much better insulation. Highly recommend QSI to anyone.Mark, Ancaster
  • We are very impressed with QSI. The installer’s are very professional, and they got the job done quickly, but were very efficient. In every way we would rate QSI excellent!Gramigna, Smithville
  • Just had two new windows installed. Competitive price but best part was attention to detail and cleanliness during installation. These guys are efficient and competent and the new windows look great! Well done. You’ve earned a repeat and loyal customer!Glenn, Burlington
  • We had our original windows replaced in February. These guys were quick and friendly! What a difference the new window make with keeping the house comfortable. They did a beautiful job and I wouldn’t hesitate to recommend them to anyone (-:Jennifer, Hamilton
  • QSI provided a great experience in our purchasing of replacement windows, and doors. Their experienced crew very efficiently installed the new windows and doors, and the quality of product was excellent . Clean-up was super and there were no problems. We were extremely satisfied. James their salesman was terrific in suggestions.Robert, Ancaster
  • Phenominal. The workers worked very well together. One did one thing, while the other did something else. They cleaned up everything both inside and out. The cost is a little bit higher, but it is money well spent. I would use them again in a minute.Jim, Haldimand
  • I would like to say that i had QSI come in and give me a quote on windows then we decided to go with them and we got our windows on the main floor done and a couple of the basement ones done. They did a excellent job and they did it in a timely matter and cleaned everything up. I was very happy with the service from them.Diane, Hagersville
  • Sales representative was very professional and helpful in selecting the product and style they we were looking for.. the product had a slight defect and the representative was very responsive to our concerns and the result was very satisfied customers. we have employed this company many many times over the years and have yet to be disappointed in their workmanship, product line or professionalism.Sally, Farmington
  • We needed windows replaced in our entire house and had QSI supply and install the windows. They were very informative during the consultation and measurement appointment. When the installers arrived, they were polite and professional. They took their time in completion of the details of installation, such as the appearance of the caulking and cleaning all of the windows when they were done. They also finished the inside of the new windows for us.Lou, Brantford
  • The windows are wonderful, quiet, and much warmer.The men did great work, everything placed in to a tee. The windows were framed with nice solid wood,not plastic or skimpy looking wood, nicely mitered and cleaned up after the job was finished. They took all the garbage away and left nothing behind. This job was done over a year ago and we are still very happy. Thanks guys.Brenda, Beamsville
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