Insulation myths are just like all other myths—you should always think critically and dig a little deeper to separate the myths from the facts.
MYTH: Insulating the ceiling will just cause more heat to leak out of the windows.
TRUTH: Adding insulation to one part of a home won't increase the "pressure" on heat losses through other parts. However, it is true that poorly insulated areas will be the major losers of heat, and that they often merit attention before improving already well-insulated parts of the home. To best insulate a home, large and small leaks must be addressed.
MYTH: More insulation is always better.
TRUTH: Unless insulation is installed properly and combined with proper air sealing, it doesn’t perform up to its potential. Depending on your climate, extra insulation may not improve efficiency or comfort enough to make the investment worthwhile. You have to consider the entire house as a system and make your decisions on insulation accordingly.