inland Window and doors


Fiberglass is a great frame material for windows and is known for its strength, durability and performance. As a building material, fiberglass is nothing new. It’s been around for a long time- floating boats and adding strength to ladders for many years. But, until recently, the complex profiles required for window designs have been impossible to attain with fiberglass. You can buy fiberglass windows and patio doors designed to maintain their beauty in every season, in any climate.

Fiberglass windows look like wood. They can be painted and stained, and come in a wide array of colors but best of all fiberglass is impervious to water, cold, heat and ultraviolet rays. Unlike wood, fiberglass frames won’t crack from dryness, swell, peel or warp. What’s more, because fiberglass frames are basically glass fibers and resin, the frames expand and contract very little and at about the same rate as glass. This puts less stress on the seals and increases their durability and effectiveness.

Advantages of Fiberglass

Fiberglass is produced using a process called pultrusion. Glass rovings and mats are pulled at tremendous forces through a resin bath and a series of dies. These materials combine and catalyze to provide tensile and torsion strength. All final products undergo extensive testing for quality and consistency.

  • Traditional wood profile
  • Extremely strong—can hold large expanses of glass
  • Low maintenance
  • Paintable

The Ultra™ Series

Is the ultimate window frame material for new construction and fiberglass replacement windows.  Because it's made of glass fibers, it expands and contracts at the same rate as the insulated glass it holds, thereby putting less stress on the seals, reducing the chance for seal failure and creates a clear, fog-free window that lasts for years and years.

All of our fiberglass windows withstand the harshest weather yet look like traditional painted wood windows. Milgard offers the option of custom colors applied at the factory, all custom made to your home's exact specifications at no extra charge, and no extended lead time. Custom hardware finishes are available from our wide selection of hardware finishes and grid options.  And, all Milgard fiberglass windows are covered by our Full Lifetime Warranty with Glass Breakage.

Select an Operating

Ultra™ Series Window

  • Single hung Ultra™ Series Fiberglass Window
  • Double hung Ultra™ Series Fiberglass Window
  • Horizontal Slider Ultra™ Series Fiberglass Window
  • Picture Ultra™ Series Fiberglass Window
  • Radius Ultra™ Series Fiberglass Window
  • Casement Ultra™ Series Fiberglass Window
  • Awning Ultra™ Series Fiberglass Window
  • Bay Ultra™ Series Fiberglass Window
  • Bow Ultra™ Series Fiberglass Window