Your state and local building codes probably include minimum insulation requirements, but to build an energy-efficient home, you may need or want to exceed them. For maximum energy efficiency, you should also consider the interaction between the insulation and other building components. This is called the whole-house systems design approach.
To properly insulate a new home, you first need to know where you need to insulate and the recommended R-values for each of those areas. Use the U.S. Department of Energy's Zip-Code Insulation Program to determine where you need to insulate and the recommended R-values based on your climate and type of heating and cooling system, etc. The program also will provide cost estimates and a rate of return.
Once you know where you need to insulate and the recommended R-values, review our information on the types of insulation available to help you decide what type to use and where.
Before you insulate a new home, you also need to properly air seal it and consider moisture control.
Article source: The U.S. Department of Energy’s Office of Energy Efficiency and Renewable Energy (EERE). For the most up-to-date information please visit the EERE website.