Your roof and attic will play the most crucial role in your home's energy efficiency "system," reducing your energy costs not only during the winter heating season, but during the summer as well.

The standard is a minimum of R-44 attic insulation, or R-46 for optimum energy savings.

Raising the roof

The area where the roof meets the sidewalls is prime spot for air leaks, so ask your builder about "raising the roof." You can choose from a standard four-inch truss, and eight-inch "energy-efficient" truss and the "super-efficient" 12-inch version.

Choosing an eight- or 12-inch "raised-heel" roof truss allows extra room to add insulation along the edges of the attic. This construction option might increase your initial costs by about $500, but the costs can be paid back in energy savings within the first year.

Cathedral and vaulted ceilings

Keep in mind that "raising the roof" doesn't mean raising the ceiling. While cathedral and vaulted ceilings are very popular in new homes, they greatly minimize the area available for attic insulation.

Make sure your builder properly insulates your high ceilings with rigid foam board insulation, while allowing for adequate ventilation.

Don't forget the shingles

The type of shingles on your roof can also affect energy use. Dark gray or black shingles will trap a large amount of heat during the summer, but absorb only a small amount during the winter when it's needed.

Light-colored shingles, on the other hand, can help reduce attic temperatures by reflecting the sun's rays.