Fiberglass Windows

Fiberglass windows consist of strands of extremely fine glass fibers made from silica sand, limestone, and soda ash. These strands are woven together, pulled through a resin bath, and then placed in a heated die to cure. The frames have air cavities that can be filled with foam or a hollow core, providing excellent insulation, while the frame expands and contracts at the same rate as the glass window pane it holds. This minimized expansion and contraction reduces the leakage of air, making fiberglass an extremely energy-efficient window material.

Top Fiberglass Window Benefits

  • Fiberglass windows provide the highest level of energy efficiency available.
  • Fiberglass is extremely durable with a lifespan of 50-80 years.
  • Fiberglass doesn’t warp, crack, or rust and is extremely difficult to damage.
  • These windows are available in a range of styles and colors perfect for any home design.
  • Fiberglass is environmentally friendly and a great choice for eco-conscious homeowners.

The Finest Fiberglass Manufacturer Chosen For You

Let us use our experience and industry knowledge to your benefit. With over 30 years in the window industry, time has allowed us to determine the clad-wood manufacturer’s who deliver the best blend of quality and price, or best VALUE for you. Our chosen manufacturer partners create value in four essential areas: consistency of quality and service over the years, level of warranty support to you, industry longevity, and product innovation. Our valued manufacturer partners for clad-wood windows is:

The Milgard Ultra Series fiberglass windows are top of the line when it comes to window technology. Fiberglass is an eco-friendly window material that provides the highest energy-efficiency levels available. Fiberglass is made primarily of silica sand, an abundant natural resource. Glass is made primarily of sand. Thus the frame and glass expand and contract at roughly the same rate while remaining resistant to swelling, rotting, and warping, allowing for a longer lifespan.

Features and Benefits: 

  • Extremely durable with an expected lifespan of nearly 80 years.

  • Strong frame material allows for large custom sizes

  • Paintable frames that homeowners can update to match current home color trends

  • Low expansion/contraction rate through 100-degree temperature changes means less glass and caulking failure over time

  •  An Energy Star package tailored to the Seattle region for optimal energy efficiency.

  •  Custom colors, hardware, and glass options to match any home design.

 

Milgard Ultra Series C650 Fiberglass Windows

Window Configurations Combinations Hardware Features Color Options Grid Options Glass Textures Tint Options Screen Options
Picture window
Picture window 2-lites verticle
Picture window 2-lites horizontal
Picture window 3-lites verticle
Picture window gable
Picture window 3-lites horizontal
Picture window gable triangle
Picture window hexagon
Picture window octagon
Gable (3-side, 4-side, 5-side)
4-sided gable and square picture windows
Picture window over awning
4-sided gable windows over picture windows
Folding Nesting Operator
Sash locks
Interior Colors
White (any exterior color)
Harmony (harmony exterior only
Bark (bark exterior only)
Black bean (black bean exterior only)

Exterior Colors
Frost
Harmony
Bark
Black bean

Interior Grids
Flat GBG Grid
Sculptured GBG Grid
3/4″ Vintage SDL
1-1/8″ Vintage SDL
1-1/8″ Craftsman SDL
1-1/8″ Legacy SDL

Exterior Grids
Flat GBG Grid
Sculptured GBG Grid
3/4″ Vintage SDL
1-1/8″ Vintage SDL
1-1/8″ Craftsman SDL
1-1/8″ Legacy SDL

Obscure Aquatex
Obscure Clear 42
Obscure Delta Frost
Obscure Frosted Glue Chip
Obscure Glue Chip
Obscure Matelux
Obscure Narrow Reed
Obscure P516
Obscure Rain
Cardinal Low-E
Solar Bronze
Solar Gray
Standard Mesh
PureView Mesh
Milgard Ultra Series C650 Fiberglass Picture Window Size Chart

Comparing Fiberglass to Vinyl and Clad-Wood Windows

When compared to other window materials, we consider fiberglass to be the highest quality material available. It provides optimal levels of performance and durability along with a considerable number of design options.  

While fiberglass is certainly more energy-efficient and durable than vinyl window materials, it’s also significantly more expensive. Because of this, we recommend fiberglass windows to homeowners who want the best material money can buy and vinyl windows for homeowners who desire comparable performance at a more affordable price. 

When deciding between fiberglass and clad-wood windows, the decision boils down to your design preference. While fiberglass outperforms vinyl clad-wood windows, they are better suited for modern home designs whereas clad-wood windows are an excellent choice for traditional home designs. 

 

 

Milgard Ultra Series

Milgard Tuscany Series

Milgard Trinsic Series

ProVia Aeris Series

Frame Material

Fiberglass

Vinyl

Vinyl

Vinyl Clad Wood

Strength

Excellent

Excellent

Very Good

Excellent

Durability

Excellent

Very Good

Very Good

Very Good

Large Size & Custom Designs

Excellent

Very Good

Good

Excellent

Energy Efficiency

Excellent

Excellent

Excellent

Excellent

% Glass to Frame

Excellent

Very Good

Excellent

Very Good

Curb Appeal

Excellent

Excellent

Excellent

Very Good

Exterior Colors

6

7

7

19

Warranty

Excellent

Excellent

Excellent

Very Good

Price

$$$$

$$$

$$

$$$$

 

Top-Rated Window Installation for the Seattle-Tacoma-Gig Harbor-Everett Area

When you choose Lake Washington Windows and Doors for your window installation project, you’ll receive the highest quality windows available, delivered with unsurpassed customer service. And with every installation you get Lake Washington Windows and Doors' exclusive Leak Armor Installation that ensures the best protection around your window openings.

Financing Options with Convenient 10 Minute Approvals   

In addition to special offers and promotions, ask  our sales representative about our quick, digital financing application process.   From low-interest traditional loans to no down-no payment-no interest deferred financing plans,  we can help you fund your replacement window project so you can mobilize your cash for other investments.  We are a proud partner of Enerbank Finance, the largest lender for the home improvement industry.   See how much you can be pre-approved for.  

Every Window Includes a Limited Lifetime Warranty

The beauty of working with the top window manufacturers in the industry is the support you can expect before, during, and after installation. Both Milgard and ProVia offer limited lifetime warranties. However, the likelihood that you’ll need to take advantage of these warranties is low.

Milgard Lifetime Warranty Guarantee

Milgard’s award-winning windows and doors are built to last. However, if you ever encounter an unexpected problem, you can rest assured that their lifetime warranties cover your purchase.

ProVia Limited Lifetime Warranty Guarantee

ProVia offers limited lifetime warranties, covering the original customer and up to one subsequent homeowner, on all their windows and doors for those who need assistance.

Receive Our Patented Leak Armor Protection with Every Installation

We include our patented Leak Armor protection with every window we install. Developed through thousands of customer installations and years of experience, we utilize layers of flashing, pans, and sealants in a specific manner to provide commercial-grade sealing to residential homes.

Fiberglass Window FAQs

Are Fiberglass Windows better than vinyl?

From a performance perspective, fiberglass outranks vinyl in strength, durability, energy efficiency, and maintenance. However, when considering the cost and desired aesthetics of your windows, choosing which material is “better” comes down to a homeowner’s personal preference.

Are Fiberglass Windows worth it?

The popularity of fiberglass windows is higher than ever. While the upfront cost is more significant, fiberglass provides benefits that vinyl windows simply do not. If you’re willing to spend the money upfront and reap the return on investment over time, then fiberglass windows are a worthwhile option for you and your home. 

Are Fiberglass Windows better than clad-wood?

When deciding between fiberglass and clad-wood windows, the decision boils down to your design preference. While fiberglass outperforms vinyl clad-wood windows, they are better suited for modern home designs whereas clad-wood windows are an excellent choice for traditional home designs. 

What style and color options are available with fiberglass windows?

Fiberglass is a versatile material that can be molded and configured into most window styles. Milgard offers a range of interior and exterior colors along with several different glass textures and window grids. Visit our window style page to explore the fiberglass options we provide.

Are fiberglass replacement windows durable?

Fiberglass windows do not very damage easily. They will resist dents, scratches, warping, rotting, and corroding. The material is also strong and rigid, allowing fiberglass windows to be up to eight times stronger than vinyl windows and require much less maintenance.