US building codes are also increasingly strict about insulation and energy efficiency. Premium home builders go even further with insulation. In some locations, new houses are so well insulated and sealed that extra fresh air heat recovery units are necessary to exchange the indoor air.
I recently noticed in the house I just purchased that a lot of cold air was coming in behind my kitchen cabinets and appliances. I pulled out my range and noticed that cold air was rushing through the gap between the drywall and the floor. Fortunately a can of expandable foam was an easy fix.
This house is only 2 years old. Corners were cut when building which makes this home not as efficient as it could be. I'm hoping to make gradual improvements.
Even though my electricity rate is only around $0.12/kwh and my gas bill isn't high, I'd still like to do what I can both for the environment and to save money.
In Canada (Quebec) we pay 0.06$/kWh but the government gives incentive for energy efficiency as a tax deductible.