Our Story

aboutDiamond Windows & Doors was founded in 1992 by Tony Tseng. Tony followed in his father’s footsteps into the building and construction industry as a contractor and property developer in Taiwan and later New York City when he arrived to America. After years of experience in the big apple, Tony decided to take his knowledge to Boston and start Diamond Windows & Doors. Using his understanding of the industry, Tony has made it his goal to meet and exceed the requirements of architects, developers, and home-owners. With this knowledge and the contacts that he has made over the years, Tony soon had a successful window manufacturing business operating out of a 20,000 sq-ft facility in the Brighton-Allston neighborhood.

Following the exact standards required in the construction industry, Tony has stayed true to his roots. Knowing that the quality of a house, loft or condo, is only as good as what you put in it, Diamond seeks to maintain a high standard for our products. With this in mind, our vinyl windows have already evolved into a third generation of high performance windows as we are always looking for ways to improve our product. This includes sourcing and comparing the highest quality materials and hardware out there. With the boom of the vinyl industry back in the 1990s and early 2000s, Tony decided it was time to take it to the next level and upgrade Diamond’s facility. This led to the acquisition of a 100,000 sq-ft facility in Dorchester, a local neighborhood in Boston.

As our customers’ needs have grown, so have we. Diamond has enjoyed steady growth over the years and is continuously looking for new ways to expand and improve our product lines, as well as our manufacturing systems. Since moving into our  facility in Dorchester, we’ve expanded beyond residential windows to offering a full line of heavy commercially rated aluminum windows as well as custom replicated historic windows for projects that must meet the strictest of historical and landmark building codes. These projects have included replacing old steel and wood windows with our thermally broken aluminum windows. Not only can our aluminum windows be used in historic applications, they have been used as part of storefronts, in-door divider systems, and new construction projects.