(From their site) Whether you are remodeling, renovating or building a new home, Alside vinyl windows deliver unmatched beauty and state-of-the-art performance for energy savings, reduced maintenance and a more comfortable home.
Each window is custom-made from virgin vinyl resin combined with the best stabilizers and impact modifiers for consistent color and strength. Alside insulated glass units use the latest technology to ensure the best possible insulation performance and seal strength. And Alside features a wide array of styles, decorative options, complementary trim selections and performance packages for a fully customizable product to suit your personal style.
Alside windows are custom-made to fit your current window openings precisely. They are easier to install because they require no additional wall construction, in comparison to stock windows found at your local retailer.
Featuring a broad range of styles; from single- and double-hung, sliding, fixed lite, casement and awning, bay, bow and garden window models – and even patio doors; Alside understands that your vision has no limitations. Without compromising performance or beauty, our unlimited choice of products are designed to bring your vision to reality. Visit their site
The superior performance of Sheffield® windows starts with innovation. Every precision-engineered component contributes to superior energy savings. The multi-chamber design helps trap dead air to produce an effective insulating barrier, while extra-thick, fusion-welded frames and sashes provide superior structural strength and create a permanent barrier against air and moisture infiltration, adding up to greater energy savings – and lower utility bills.Learn more

There's a unique feeling of confidence that comes from knowing you have chosen UltraMaxx® windows from Alside. They are not only beautiful; their heavy-gauge, fusion-welded vinyl sash and mainframe structure makes them incredibly strong and tough. Years of operation and harsh weather won't diminish their quality or performance. And they offer superior resistance to the elements and to air and water infiltration. Learn more

Excalibur® windows from Alside are beautiful and remarkably solid, sturdy and stable. Plus, our beveled mainframe design is exceptionally slim and refined. Their sleek construction easily complements any type of architecture
You’ll find that Excalibur vinyl frames will never chip, peel, crack or warp, and will never need painting or caulking. And Excalibur's tilt-in sashes make cleaning a pleasure. You'll save money on energy bills because Excalibur's superior all-weather performance helps reduce heating and cooling costs. Learn more