R5 Triple Pane Windows and Patio Doors

R5 insulation rating = U-value .20

R5 is Eco-Friendly Energy Efficiency

Common Energy Star windows and patio doors only have an R rating of 3. We designed a series with an R rating of 5 for the ultimate in energy efficiency.

How Much Difference Does an Energy Efficient Window Make?

Heat and cold transfer through windows causes approximately 30% of heating and cooling energy costs nationally. That is an annual 4.31 quadrillion BTU of energy consumption.

R5 = U-Value .20

U-value is the rate of heat flow through a window; the lower the value, the better the insulating quality. Most commonly the U-value is used to measure a window's total insulating value. R-value is the resistance of a material to heat flow; the higher this number, the better the insulating value.


  • Reduced heat loss in the winter, better than typical Energy Star or Low-E windows
  • Potential for significant reduction in energy costs
  • Moderate to significant reduction in noise levels compared to double pane windows


  • Triple-Glazed: the insulated glass unit on an R5 window has three panes of glass
  • Krypton Gas Filled Between the Panes: Krypton has significantly better insulating qualities than Argon
  • Double Low-E glass: Low-E is on the exterior pane and the interior pane

Lang Windows and Patio Doors with the R5 Upgrade

R5 is available on all Lang vinyl windows and patio doors, except Rezilience:

Platinum Series
Powerweld Series
Renaissance Series
Glide Patio Doors (Vinyl)