The RESISTA is a Passive-House Certified series with aluminum-clad frames for windows and doors, durable Roto hardware, available in several wood and finish options. Frames are optimized for over-insulation and smooth thermal-bridge free installation into walls.

All Optiwin windows are available in Custom Dimensions and Fully supported by 475 for best performing installation detailing (thermal bridges/airsealing).

For Custom Solutions:

Product Specifications


  • Class A Passive House certification
  • Frame width: 3 11/16" (95 mm)
  • Gaskets: 4
  • Suitable for low energy and Passive house in most USA climate zones
  • Narrow frames that are optimized for over-insulation in high R-walls
  • Customizable high or low SHGC
  • Options for hardware, insect screens, alu-sills and interior/exterior finishes
  • Foam-free frames insulated with wood fiberboard
  • Exterior finish: available in any RAL color of your choice
  • Interior finish: available in a variety of interior finishes
  • Options for hardware, insect screens, alu-sills and roller shutters


  • Customizable high or low SHGC (30-40-50)
  • Uwindow: 0.132 Btu/h ft2 F (0.65 W/m2K)
  • Uglass: 0.088 Btu/h ft2 F (0.5 W/m2K)
  • Super Spacer: 0.016 Btu/h ft2 F (0.23 W/m2K)