For years in Canada we've already been building to standards like these, and more. Better insulation and tighter construction cost more up front but are cost-effective by reducing energy costs over time. The higher energy costs go, the more significant the saving.
Some financial institutions allow a higher mortgage payment for super-insulated houses because they know the household's utility bills will be less than average.
One financial advisor I know says that rather than investing in stocks, bonds, etc., many households would get a higher return on investment (tax-free, no less) by putting more insulation into their attics. Only after you've done everything you can to make your home more energy-efficient should you start "regular" investing.
