In-Depth: Integrating the Defender 88PH+ Window into the B.PUBLIC Prefab R35 Performance Wall

November 4, 2025
In Depth

The Defender 88PH+ window system manufactured by Innotech Windows + Doors is engineered for seamless integration into the B.PUBLIC Prefab R35 Performance Wall, a high-performance panelized wall assembly designed for exceptional energy efficiency, airtightness, and durability. Together, these systems create a resilient enclosure solution that delivers consistent results—whether assembled in a factory or installed on-site.

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Structural Integration

The Defender 88PH+ is installed using steel strap anchors that connect the window securely to the structural framing within the R35 Performance Wall. This method ensures proper load transfer while maintaining the integrity of the continuous insulation layer.

Steel strap anchors on top and sides are positioned to distribute loads evenly, as well as accommodate for building settlement and movement over time.

• A 1 ½″ × 1 ½″ steel L-angle at the sill provides a provides a structural connection and a continuous back-dam.
• A 1 ⅛″ plywood sill plate provides a durable substrate for anchoring and long-term stability.
• A face-mounted header above the window supports structural continuity in alignment with the wall panel’s framing system.

Thermal Continuity

The window is strategically positioned within the insulation plane of the R35 Performance Wall, ensuring a smooth transition between the window frame and wall insulation.

• The hybrid frame of the Defender 88PH+ provides a thermally broken connection that limits conductive heat loss.
• This alignment maintains the wall’s high thermal performance by preventing thermal bridging at the rough opening.

Air and Water Control Layers

Air and moisture management are key to long-term performance and durability. The Defender 88PH+ installation employs multiple, redundant layers of sealing to ensure continuous protection.

• TESCON VANA tape is applied at the exterior frame-to-wall interfaces to provide airtightness and a water barrier.
• EXTOSEAL ENCORS tape at the sill acts as the impermeable primary water barrier, channeling any incidental moisture outward while protecting the substrate. The EXTOSEAL ENCORS tape wraps from the exterior panel face to the solid back-dam and up to create a seamless watertight barrier.
• CONTEGA SOLIDO IQ tape is applied to the interior frame-to-wall interface to provide a smart vapour permeable continuous airtight layer.
• All connections are integrated with the B.PUBLIC Performance R35 wall’s air and water barrier membranes to maintain system continuity. The following combined membranes in the wall assembly ensure robust air, water and vapour control layers:
  -The exterior face is sealed with the SOLITEX ADHERO 3000, a self-adhering monolithic vapour permeable weather resistant barrier membrane.
  -The interior face is sealed with the INTELLO X, an airtight smart vapour variable membrane.

All air and moisture management products mentioned above are available from 475 High Performance Building Supply.

High Performance Synergy

The integration of the Innotech Defender 88PH+ with the B.PUBLIC R35 Performance Wall represents a thoughtful balance between engineering precision and building science. This combination delivers:

• Airtight, watertight, and thermally robust enclosures
• Predictable installation quality in both panelized and site-built applications
• Exceptional thermal, energy and acoustic performance aligned with high-performance building standards, such as the Passive House standard

By aligning prefabricated enclosure systems with advanced fenestration engineering, these systems are helping to define the next generation of low-carbon, high-comfort, and high-performance homes.

For additional information on B.PUBLIC Prefab’s many wall, floor and roof solutions, visit www.bpublicprefab.com.

Ready to master high-performance prefab construction?

Join B.PUBLIC Prefab for their upcoming Builder Training, where installers, contractors, and construction professionals get hands-on experience assembling the R35 Performance Wall and learning proven installation techniques for airtight, durable, high-performance envelopes.

• Hands-on wall + window installation
• Best practices for airtightness, water management, and detailing
• Learn directly from the B.PUBLIC team of enclosure experts

Date: January 23-24, 2026
Location: Las Vegas, New Mexico

Space is limited—register today to secure your spot.