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GreenGirt XO™

GreenGirt XO™ is a structural thermal framing system for windows and openings.
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Stop losing money
at the perimeter

Fix the connection your energy model ignores, and outperform every other efficiency upgrade on the project—GreenGirt XO is the structural thermal framing system designed to do exactly that.

Structural thermal framing system for windows and openings

GreenGirt XO™ is a structural thermal framing system for windows and openings. Proudly made in the USA by Advanced Architectural Products, GreenGirt XO effectively tackles the critical challenge of thermal loss at building openings by eliminating through-wall metal, conductive metal angles, and inefficient wood-blocking. By aligning the thermal plane of the window with the thermal plane of the insulation, the overall efficiency of the building envelope is enhanced by the GreenGirt XO system, achieving up to 97% thermal efficiency and more than doubling the effective R-value when compared to legacy systems. Supported by expert engineering, this system seamlessly integrates into the building’s façade, providing a sophisticated and efficient solution to optimize window and opening performance. Engineered with true flexibility in mind, GreenGirt XO accommodates a wide range of window types and sizes. Its modular design allows customization to project-specific requirements. The system includes composite fiberglass headers, sills (with or without integrated rails) and jambs; aluminum and galvanized dead load clips; header angles; header, jamb, and sill aluminum flange inserts (available in standard and spacer variants); and self-sealing anchor plates, all customized to your project in collaboration with the A2P engineering team. To understand the problem GreenGirt XO solves and how to evaluate any window framing system, read our guide to structural thermal window framing.
How It Works
Downloads
How to Install
 
How It Works

The GreenGirt XO system adheres to the eight continuous insulation best practices. Additional features that make the GreenGirt XO system stand out as the best choice for your building include:

Doubling Thermal Efficiency at Windows

GreenGirt XO aligns the thermal plane of the window with the thermal plane of the insulation for enhanced energy performance—meeting the window alignment requirements in ASHRAE 90.1-2022.

 

Designed for Versatile Opening and Insulation Options

GreenGirt XO is flexible to meet the needs of any building opening, including punched openings, storefronts, curtain walls, and ribbon windows, to ensure seamless integrations and superior performance. Also designed to work with any type of insulation.

Eliminates Metal Angles and Wood Blocking

Revolutionize your build by replacing traditional metal angles and wood blocking with innovative composite metal hybrid materials for a more efficient and sustainable construction approach.

Resistant to Creep and Fatigue

Engineered with advanced composite metal hybrid materials, GreenGirt XO prevents fastener creep, resists fatigue and ensures lasting structural integrity.

Committed to Sustainable Design

By increasing energy efficiency at building openings, GreenGirt XO reduces energy waste, conserving resources and reducing embodied carbon emissions. To ensure full transparency, GreenGirt XO is complete with a Declare label, an EPD, and uses Red-List free materials.

GreenGirt CMH XO

GreenGirt XO™ Configuration Options

Compatible InsulationMineral wool, spray foam, rigid insulation
System ComponentsGreenGirt XO structural support, integrated aluminum flanges
Compatible SubstratesCMU, masonry, metal studs, wood studs
GreenGirt XO Length96"
GreenGirt XO Depths2", 3", 4", 5", 6" (1/2" spacers can be used to accommodate all depths)
Compatible Insulation Thickness2", 3", 4", 5", 6" (1/2" spacers can be used to accommodate all depths)
Compatible CladdingAll
Drainage Plane LocationBehind or in front of GreenGirt XO

Downloads

Download essential technical documents to streamline your design, specification, and installation process.
Brochure
Installation Guide
Safety Data Sheet
Installer Notes
Details
CAD Files
REVIT Files
LEED Worksheet
EPD
Specifications
AN Best of Products award badge for GreenGirt CMH XO
The GreenGirt CMH XO structural thermal framing system for windows shown installed on stud wall framing with sheathing, weather-resistive barrier, GreenGirt CMH Z-girt system, mineral wool insulation, and cladding.
The GreenGirt CMH XO system installed with GreenGirt CMH Z-girts for maximum thermal efficiency, bringing the thermal plane of the window forward and into alignment with the thermal plane of the continuous insulation system.
Comparing legacy framing systems to the GreenGirt CMH XO system: a clear demonstration of how aligning the window with the continuous insulation layer will more than double the window’s thermal efficiency.
The full set-up of the GreenGirt CMH XO structural thermal framing system for windows, consisting of modular composite fiberglass header, sill, and jambs, with aluminum flange components and dead load clips, prior to installation showcasing how the different components will fit together.
The composite fiberglass sill component (without standard integrated sill) of the GreenGirt CMH XO system, prior to installing modular aluminum flanges and dead load clips, demonstrating the various depth options in 2, 3, 4, 5, and 6 inches.
The composite fiberglass header component of the GreenGirt CMH XO system, prior to installing the aluminum header angle or header flange, with options for various depths of 2, 3, 4, 5, and 6 inches, for a fully aligned, high-performance frame.
The composite fiberglass left jamb component of the GreenGirt CMH XO system before adding the modular aluminum flanges, showing various depths (2, 3, 4, 5, and 6 inches) available for customization.
The composite fiberglass right jamb component of the GreenGirt CMH XO system before adding the modular aluminum flanges, showing various depths (2, 3, 4, 5, and 6 inches) available for customization.
The modular aluminum header angle flange insert for GreenGirt CMH XO separate from the composite fiberglass base, designed to eliminate water intrusion and direct water away from the header.
The modular header, jamb, and sill aluminum flange inserts available for attachment to the composite fiberglass components of GreenGirt CMH XO. In standard and spacer (plus half inch) variants. Pictured left to right: mini flange insert, mini flange spacer insert, flange insert, flange spacer insert, header angle insert, and header angle spacer insert.
An underside view of the dead load clip options available for installation with the composite fiberglass sill component of the GreenGirt CMH XO system, customizable for sills with integrated rails and aluminum dead load clips (top) or with a smooth sill plate and galvanized dead load clips (bottom).
The different sizes available for GreenGirt CMH XO’s aluminum dead load clips—providing varying capacity, sizing, and spacing options to meet project-specific structural requirements based on window size, type, etc.; engineering/design included with every GreenGirt CMH XO order.
The full integration of the GreenGirt CMH XO system’s modular sill component, with the forward-facing aluminum flange insert and two dead load clips attached to the composite fiberglass sill (with integrated rail) before installation.
A section of the GreenGirt CMH XO system’s header with the modular aluminum header angle insert attached to the composite fiberglass base, ready for installation
The GreenGirt CMH XO system won the BUILDINGS 2024 Product Innovation Award, which recognizes innovation in building materials and solutions for architects, building owners, facility managers, and product specification influencers. A2P is proud to have GreenGirt CMH XO highlighted for its innovation in structural framing, increasing thermal efficiency that goes above and beyond legacy systems.
The GreenGirt CMH XO system was announced as a finalist for the 2025 Architizer A+ Product Awards in the Architectural Design category. This award highlights the best products of 2025 in the world. A2P celebrates this achievement as GreenGirt CMH XO continues to deliver innovation to securing windows structural integrity and thermal efficiency.

Frequently Asked Questions (FAQs)

What is GreenGirt XO™?

GreenGirt XO™ is a structural thermal framing system for windows and openings designed to reduce thermal loss by eliminating through-wall metal, through-insulation fasteners, conductive metal angles, and inefficient wood blocking.

The GreenGirt XO™ system is assembled from project-customized components coordinated with our engineering team, including composite fiberglass headers, sills (with or without integrated rails), and jambs. The system also includes aluminum and galvanized dead load clips, header angles, standard and spacer aluminum flange inserts for the header, jamb, and sill, and self-sealing anchor plates.

GreenGirt XO™ is supplied in 96-inch lengths and offers widths of 2, 3, 4, 5, or 6 inches, with 1/2-inch spacers available to accommodate all depths.

The flanges on GreenGirt XO™ are aluminum and don’t have a stainless steel option. The dead load clips, however, are available in aluminum (standard), 1/4″ steel (galvanized or stainless), and 12-gauge steel (galvanized or stainless), so stainless is available on the dead load clips for coastal, high-humidity, or otherwise corrosive environments.

GreenGirt XO™ is compatible with all cladding types, including ACM, fiber cement, metal panel, high-pressure laminate, stucco, brick, terracotta, stone, GFRC, wood, and copper.. On the substrate side, it’s compatible with masonry, concrete, or metal or wood studs with sheathing.

GreenGirt XO™ is compatible with mineral wool, spray foam, and rigid insulation, in thicknesses from 2″ to 6″.