With 300+ square feet in windows spec’d for the house, I have been doubtful about whether it would be feasible to stay within budget and specify high-performance triple pane window. However, today I got the answer to that question-a resounding yes!

Intus windows which are well-loved by the Passive House community make an extraordinarily high performance triple pane window available at $26 a square foot. They sport a u-value of 0.126 which translates to an R-8. For comparison, Andersen 400 series windows which are typically regarded as high-performance are typically an R-2 and no where near as beefy as the Intus.

I had an opportunity to visit Performance Building Supply in Portland which is the northeast dealer for Intus Windows. They have both installed windows and cut-away sections in their showroom. Seeing the window “in-the-flesh” certainly sold me on using Intus instead of an Andersen or Marvin.

Performance Building Supply was quite knowledgable and offered to support the Builder through the install of the window. The only downside to the window is the 12-14 week lead time.

Now that the window is chosen, the challenge becomes adequately detailing installation procedures which result in a great seal between the windows and SIPs.