Myth #6: Six Inches of fiberglass equals R-19 and pretty good for Maine.
Truth: NOT!!! Effective R-value of this type wall is actually R-12 or lower.
Wood framing every 16 inches (R-value = 5), represents 20% of the area of the wall and lowers the overall R-value. Added to that, fiberglass insulation is not a good air infiltration barrier (leaky!) and you have a pretty poor insulation method for Maine
Goals for New Construction: We recommend an effective R-40 minimum walls with no thermal breaks and very tight. For Deep Energy Retrofits, we recommend a minimum of R-30.