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Fiberglass Composite ThermoPlus Casement is coming out at the end of 2022! Our newest introduction, purposely created to meet Passive House Standards, fulfills the requirements of our most forward thinking and design minded residential and commercial clients for performance windows. The ThermoPlus Casement represents the fullest expression of what we call the Art + Practice of Fenestration bringing further value to our 1800 Series Casement portfolio, and a partner to the very successful 4700 Series.


  • Improved Thermal Performance without requirement of steel
  • Sizes that accommodate up to 30 % larger openings before needing steel reinforcement going over 76 in (1.9 m) in height
  • Fusion-welded corners offer increased thermal and acoustical performance
  • Permanent water and air sealing
  • Multiple locking points surrounding the sash create extra security, tighter sealing and comfort
  • Industry-leading warranty with Double (25mm) and Triple (33-44 mm) glazing

Key Performance Data

           0.15 (IP)            0.85 (SI)

U-Value Best Thermal NFRC

720 Pa 
15 psf

Water Penetration Resistance

0.020 L/s*m² (A2)
0.001 cfm/ft²

Air Infiltration

* All data shown are for double paned windows and doors. For more information about performance data for specific configurations and add-ons, please speak to our design representative

Max Operating Sash Size (W or H)

42”W or 84”H (max 70’ sq glass)

Configuration Options



Small Picture

Double Casements


Fixed Sash