Residential

Zenith Series Windows

Experience comfort and home efficiency with Alpen's Zenith fiberglass residential windows. Zenith blends durability with North American style and functionality, offering energy efficiency, comfort, and lasting craftsmanship.

NFRC Certified to R-10
ENERGY STAR® Most Efficient, and DECLARE label “Red List Approved”
Variety of window types in customizable colors, including black
Proudly designed, developed and manufactured in the USA

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Design Options

Configurations

Selected:

Fixed Windows

Awning Windows

Casement Windows

Single Hung Windows

Double Hung Windows

Horizontal Slider Windows

Also available in combination assemblies and radius shapes (i.e. Arch top, Traps Casement/Fixed/Casement Combo)

Finish

Selected:

Midnight Black

Classic Collection

Pure White

Classic Collection

Umber Bronze

Classic Collection

Bronze

Signature Collection

Alpine Ivory

Signature Collection

Sand Dune

Signature Collection

Riverstone

Signature Collection

Boulder Grey

Signature Collection

Silver Mist

Signature Collection

Bison Brown

Signature Collection

Red Canyon

Signature Collection

Pine

Signature Collection

Stormy Sky

Trend Collection

Verde Valley

Trend Collection

Deep Water

Trend Collection

Split Finish and Custom Colors Also Available.

Note: Colors are representative and can vary. Request color cards or painted fiberglass samples here.

Handles

Selected:

Attraction^TM Handle

Description: The slender handle features a filled back that enhances its appearance, prevents folding, and ensures smooth operation. A concealed magnet in the cover secures the handle, creating a seamless, easy-to-clean surface. Made from durable zinc, the handle and cover come in various finishes.

Operation: For use with Casement and Awning style windows

For use with Casement & Awning style windows

Optional. For use with Single Hung and Sliding style windows

Glass

Selected:

Triple-pane

Whole-window thermal performance ratings up to R-7 (U-0.14).

Long strand pultruded fiberglass frame provides superior strength and thermal performance.

Super-insulating closed-cell foam in both the frame and sash cavities enhances thermal insulation.

Industry-leading technology allows for product availability at high altitudes.

Air infiltration rates as low as 0.01 CFM per square foot offer exceptional air-tightness and energy efficiency ding triple and quad-pane ThinGlass ensures exceptional thermal efficiency and durability.

Gas retention tech.

Enhanced sound reduction capability.

As a global leader in ultra energy efficient window, door and glass solutions, all Alpen Zenith Series fiberglass windows and doors are carefully designed to meet the energy efficiency needs of our changing world.

Discover our Product Catalog for more information.

Residential Zenith Series Windows - Product Catalog

[DOWNLOAD]

This specification system has been prepared to assist design professionals in the preparation of project or office master specifications. It follows guidelines established by the construction specifications institute, and therefore maybe used with most master specification systems with minor editing.

3-Part Guide Specification

[DOWNLOAD]

BIM & CAD

Awning & Casement

Double Hung

Fixed High Profile

Fixed Low Profile

Horizontal Slider

Single Hung

Grandline Sliding Door

[PDF][DWG]

Narrowline Sliding Door

[PDF][DWG]

Mulling Information

[PDF]

Zenith Series Anchor Strap Installation Guide

[DOWNLOAD]

Zenith Series Installation Guidelines-FIN Installation

[DOWNLOAD]

Fixed window NFRC Certified to U-0.10 (R-10), operable windows (open and close) NFRC Certified to U-0.14 (R-7.1)

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Why Choose Zenith?

Long-Lasting Durability

Long-strand pultruded fiberglass makes Zenith stronger than aluminum pound for pound and more durable than wood and vinyl. In the latest Inline Fiberglass lifecycle assessment of windows for the North American residential market, they found that fiberglass windows have 38% longer useful life expectancy than vinyl.
Fiberglass withstands extreme temperatures and high wind loads without maintenance worries. Fiberglass frames expand and contract very little in heat or cold—800% less than vinyl. They expand at a similar rate as glass, keeping a tight seal over years of temperature changes. This compatibility prevents air leaks and maintains energy efficiency.

Superior Water and Air Resistance

Zenith windows are built to withstand severe weather conditions and hold the AAMA certification for exceptional wind, water, and air resistance. Advanced sealing technology provides protection against water damage and air infiltration (as low as 0.01 CFM per square foot).

North American Styling & Architectural Freedom

Superior strength-to-weight ratios make the Zenith series an ideal option for large window openings. Lightweight glazing solutions and low-profile frames enable high glass-to-frame ratios, allowing more natural light.
Custom sizes, shapes, hardware options, and colors seamlessly integrate with your design plan.

Enhanced Peace and Quiet

Zenith windows provide significant noise reduction with sound attenuation performance up to STC 39, creating a peaceful and ultra-quiet indoor environment.

Healthy and Safe Living Spaces

Zenith is the first North American window certified under the Living Building Challenge Declare label "Red List Approved". This means it does not contain harmful chemicals. High-quality, low-VOC paints minimize off-gassing, contributing to superior indoor air quality.
Triple gasket seals and insulating properties prevent mold and mildew growth, maintaining a healthy living environment.
AAMA certification includes forced-entry resistance testing to help prevent forced entry. Forced entry resistance tests assess windows and doors to see how well they restrain, delay, or frustrate forced entry.

Future-Proof Your Home

Zenith windows and doors are a long-term investment that adds value to your home. They are made with durable materials and pioneering technologies like Thin Glass and Suspended Films. This ensures they meet future building standards, keeping your home's envelope ahead of the curve.
High-performance products like Zenith save you money on energy bills. They also give you flexibility for future home upgrades. An efficient building envelope can help optimize modern HVAC solutions such as electric heat pumps. This can help with long-term energy savings and a smaller carbon footprint.

Sustainability
Focused

At Alpen, we deliver exceptional value by making our top-tier windows and doors accessible to a broader audience. We want to ensure as many people as possible can enjoy the benefits of high performance. By expanding our reach, we're purposefully contributing to a greener, more climate-resilient world.

Affordability without Compromise

At Alpen, we believe in delivering exceptional value. One of our core missions is to demonstrate that high performance doesn't have to have an exorbitant price tag. We're committed to making our products accessible, ensuring that many can enjoy the benefits of high performance.
By expanding our reach, we're able to contribute to a built environment that is greener and more climate-resilient.

Ensuring Customer Success

When you invest in Alpen products, you're also buying our expertise and support for the long term. Our customer success team provides project expertise, technical proficiency, and readily available resources.
We are one of the few American-made passive house-certified window providers. As a result, our lead times are shorter than imported products. This helps to ensure your project remains on track and responsive to your demanding construction schedule. With Alpen, gain greater control over your timeline and take advantage of flexibility tailored to your team's needs.

Unparalleled Performance and Comfort

At Alpen, we set the bar for thermal efficiency with industry-leading performance ratings, far surpassing Energy Star standards and meeting the most rigorous Passive House requirements. Our residential windows and doors feature advanced, lightweight, high-performance triple and quad pane glazing that effectively blocks summer heat, retains winter warmth, and maximizes natural daylight. Enjoy unparalleled comfort in every room of your new home or after a window replacement project, throughout every season.

Certified for Passive House

Alpen was the first North American window manufacturer to achieve dual certification from both PHIUS and PHI. We specialize in high-performance building products, with a focus on energy-efficient windows and doors. Our Passive House-certified products help architects, general contractors, and developers meet or exceed modern energy codes and build climate-responsive buildings.

Explore Passive House

See Zenith in the Field

Meadow House

Fargo House

Anti-Ski House

Explore Residential Product Catalog

Frequently Asked Questions

What’s the difference between Zenith and Tyrol?

Zenith is an energy-efficient fiberglass window with North American outswing functionality, achieving up to R-10 rating. Tyrol uses fiber-reinforced uPVC frames with European inward swing functionality, achieving up to R-11. Zenith focuses on fiberglass durability and environmental benefits, while Tyrol highlights European engineering and aesthetic versatility. Both products are energy star certified.

Are fiberglass windows and doors energy efficient?

Yes, fiberglass is a highly energy-efficient insulator with low thermal conductivity, helping maintain consistent indoor temperatures. Fiberglass stability prevents air leakage and can accommodate energy-efficient triple or quadruple glazing.

What type of windows will be the most energy efficient?

The most energy-efficient windows use advanced frame materials with high thermal resistance. Then they incorporate multi-pane insulated glass units with gas fills between the panes. Finally, precise construction prevents air leakage through gaps.

How long do fiberglass windows last?

Fiberglass window manufacturers build products to last 50 years or more. Resistant to warping, rotting, and corrosion, fiberglass withstands harsh weather without deterioration. Its strength and stability maintain window integrity over time, ensuring efficiency and functionality for decades. The Zenith Series includes a full lifetime warranty while you own and reside in your home.

Why do fiberglass doors and windows cost more than alternatives?

When considering vinyl vs fiberglass windows, fiberglass has a higher material cost than alternatives. It requires complex manufacturing processes like weaving fibers into resin-impregnated fabrics under controlled conditions. Though costlier upfront, fiberglass offers superior durability, thermal efficiency, and design flexibility.

Related Products

Zenith Series Doors

Tyrol Series Windows

Tyrol Series Doors

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Zenith Series Windows

Design Options

Fixed Windows

Midnight Black

Midnight Black

Pure White

Umber Bronze

Bronze

Alpine Ivory

Sand Dune

Riverstone

Boulder Grey

Silver Mist

Bison Brown

Red Canyon

Pine

Stormy Sky

Verde Valley

Deep Water

AttractionTM Handle

Triple-pane