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Passive House Institute Cold Climate Certified Windows

Less than five years ago, Innotech Windows + Doors introduced our first Passive House Institute certified window system. Since then,  we have launched five new Passive House Institute certified components – a testament to our passion for performance and our ongoing investment in research and development.

In recent years, adoption of the Passive House standard has continued to increase in both Canada and the United States, with many building codes identifying the standard as an approved path to achieve mandated performance requirements. As a result, Innotech has manufactured and installed thousands of Passive House Institute certified windows and doors for single family homes and multi-family developments.

Innotech is excited to launch our newest Passive House Institute certified window system: the Defender 88PH+ XI. The Defender 88PH+ XI window system builds on over twenty years of high-performance fenestration manufacturing experience to reach a North American industry milestone.

Cold Climate Certified Windows Manufactured in North America

The Defender 88PH+ XI is the first Passive House Institute cold climate certified window system manufactured in North America and the first uPVC Passive House Institute cold climate certified window system manufactured in the world!

The Passive House standard as defined by the Passive House Institute (PHI) has seven climate regions. The cold climate region, or climate region 2, covers much of the northern United States and southern Canada. Cold climate certified windows must have a U-value (Uw) of no more than 0.60 W/(m²K), a U-value installed (Uw,inst) of no more than 0.65 W/(m²K) and a minimum temperature factor of 0.75 (fRsi=0.25m2k/W). These U-values and temperature factor help ensure a comfortable year-round indoor conditions for homes and buildings built to the Passive House standard in the cold climate region.

Map of Passive House Institute climate regions.

Map of Passive House Institute climate regions.


The Defender 88PH+ XI offers Passive House building professionals designing and building in climate regions 1, 2 and 3 a locally manufactured fenestration system from a long-standing Canadian manufacturer.  The Fixed Window has a Uw of 0.59 W/(m²K), Uw,inst of 0.60 W/(m²K) and temperature factor of 0.77, while the Operable (Tilt + Turn) Window has a Uw of 0.60 W/(m²K), Uw,inst of 0.64 W/(m²K) and temperature factor of 0.78. Both the Fixed Window and the Operable Window achieve a Passive House efficiency class of phA for the cold climate.

Engineered for North American Projects

In addition to PHI certification, the Defender 88PH+ XI is also certified by the National Fenestration Rating Council (NFRC) and tested to comply with the North American Fenestration Standard/Specification (NAFS). The result is a comprehensively engineered, tested and certified high-performance fenestration system with outstanding thermal insulation, air, water and sound resistance, and durability specifically designed for North American building projects.

Reliable Strength and Stability for Windows and Doors with Colour Finishes

The Defender 88PH+ XI is part of the Defender 88PH+ System product family – an advanced fenestration system that is engineered to provide strength and stability. Innovative reinforcements improve structural performance and significantly reduce thermal conductivity. This allows the Defender 88PH+ System, including the Defender 88PH+ Pro and XI, to be reliably designed in extra-large sizes and a range of durable colour finish options.

For additional information on the Defender 88PH+ XI and our Passive House Institute certified windows, click here.