[turbo6bar]

Don't see any reason to go with triple pane when the rest of your house has poor insulation. Your dollar goes furthest addressing the area with least insulation.

The triple pane I have seen start at R-4 and go up to R-6. A vanilla double pane is R-3. You're paying a large premium for 30-50% gain in insulation. Spend the bucks on sealing leaks, HVAC ductwork, and installing insulation where none existed before.

If you're really into crunching numbers, buy one of several HVAC programs that calculates heat loss/gain (Manual J calcs). You will get numbers and you can make changes in insulation levels/window R-value to see effect.

Agree with svan. Triple pane is best when used with a house design for high efficiency. Jurgen