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About GEM Windows & Doors

Founded in 1961 by John Christopoulos to manufacture and install energy-efficient storm windows and doors. From GEM’s original showroom located at Dundas & Brock, the company continued to grow and evolve, eventually relocating to its current location at 1590 The Queensway. GEM proudly features one of Toronto’s largest and most innovative industry showrooms!

Today, GEM Windows and Doors is still family-owned and operated by the Christopoulos family, offering a large selection of quality residential and commercial windows, doors, awnings, pergolas, garage doors, window coverings, and related accessories. Over the years the window and door industry has evolved and seen many companies come and go, GEM Aluminum Manufacturing, known as GEM Windows and Doors,  is the exception innovating and evolving with the industry. GEM is proud to be the oldest window and door retail company in the Greater Toronto Area.  

 At GEM two things haven’t changed, first, we still have our original phone number 416-533-4331 and the other is GEM's commitment to customer satisfaction. GEM has a well-earned reputation as Toronto’s oldest and most trusted window and door company in the GTA. Our longevity is based on our staff and their many years of experience and industry product knowledge and expertise. GEM representatives listen carefully to all our customers, assessing their needs and goals, and presenting product options and choices with solutions to meet them. GEM’s experienced and well-trained sales and production staff members look after our customers, from their first point of contact to a visit at our 5,000 square foot state-of-the-art showroom, right through to installation and beyond.

GEM’s showroom has the widest available product mix to meet our client's needs, we are design experts and GEM prides itself on value engineering any project, big or small.  GEM’s staff listens to our customers providing them with customized, unique solutions and product lines, our approach is not "one-size-fits-all", rather it's tailored to each customer's project, budget, and objectives. 

We work with our customers to accomplish their goals:

  • Making your home or commercial space more comfortable

  • Increasing your homes energy efficiency and reducing your energy bills

  • Letting in more light & maximizing the view

  • Making your home more secure

  • Addressing specific problems such as UV damage to floors and furniture

  • Reducing or eliminating maintenance

  • Improving the aesthetics of your home for better curb appeal, improved functionality, and increase overall property value






GEM Windows and Doors had been awarded ENERGY STAR Retailer of the Year in 2018 and 2019 by the Canadian Federal Government. GEM Windows & Doors continues to support ENERGY STAR and to source new and innovative products from around the world for our customers in the GTA and Southern Ontario.

“Toronto-based GEM differentiates itself by focusing on ENERGY STAR certified products, providing personalized service and professional installations, featuring innovative energy-efficient products, and thus protecting the planet along the way. GEM has instituted a long-term commitment to support the ENERGY STAR program and increase brand awareness in Canada.” - Minister of Energy 

GEM’s hard work and dedication allowed us to overcome many challenges in our industry caused by COVID-19. Being featured on the cover of the industry publication Fenestration Review GEM was able to showcase and share our success with other industry leaders to help us all through this unprecedented time. 

GEM is also a member of Fenestration Canada, which is the voice of the fenestration industry in Canada and which wrote the original CSA standards for the window and door industry.

GEM has also been awarded a HomeStars Best Of The Best Award for 2023, our third consecutive Best of Award, for our commitment and dedication to customer service and excellence of workmanship. 



GEM does not just sell any products, we do our research. GEM partners with manufacturers that offer great reliability, outstanding customer service, and the highest and very best quality product lines. We ask our manufacturers tough questions and work with them to ensure the products are what customers want, have great warranties, and are Window-Wise and Energy Star certified.

To keep up to date on the industry around the globe, our team is familiar with many key window manufacturers selling products in Canada and around the world. A fact that our manufacturing partners understand and respect. 


A high-quality windows and doors installation is just as important as the products being installed. All GEM Windows installers are experienced, well-trained, and service-oriented professionals. GEM is a member of the Window Wise Certified Installation Program. Window Wise is an independent third-party industry association of widow and door experts that verify installations to ensure the quality of the work.  GEM welcomes the idea of having an expert from the industry association inspect our installation work!

GEM’s production and installation department coordinates with our customers to get an installation date that works best for them. GEM has multiple crews that have been part of our team for over 20 years, some crews are even specialized in high-end products to ensure a top-quality installation every time. With skilled install teams GEM will not over-book our crews or rush a job just to move on to the next one. When our team pulls up to your home their focus is your installation. 

All GEM installations come with a 5-year labour warranty, and our 60+ years in business guarantees we will be around to honour our installation and labour warranties.


GEM’s pricing is competitive and in line with the current industry and market rates. GEM may not always be the lowest price, but we are always the best value (price vs quality). GEM is confident that our pricing is fair & competitive, offering a product equivalent price match guarantee. 

GEM’s Guarantee: Provide a written lower quotation for your project with products and installation of an equal quality and GEM will match the lower price and beat it by 10% of the difference.


GEM is a leader in offering energy-efficient products that help reduce CO2 emissions and reduce energy costs for our customers, offering a multitude of High Efficiency and Energy Star-rated products.  We recycle all of the glass and aluminum materials from old windows and doors we remove. Observing LEED certification principles, we’ve updated our showroom lighting (interior and exterior) to reduce energy consumption. GEM is taking steps to implement additional energy-saving measures like an all-electric vehicle fleet and recharging stations for our customers and GEM vehicles. GEM continues to look for ways to reduce our carbon footprint and do our part for the environment.

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