Southern California Gas customers may be eligible for loans for installing energy efficient windows. The loans range from $2,500 to $20,000 and are available through the Home Energy Upgrade Financing program. To apply for the loan, you'll need to connect with a Viewtech-approved contractor.

Also, through the rest of 2010, you can take advantage of the federal energy efficiency income tax credit for ENERGY STAR windows and doors. To qualify for the tax credit, which is equal to 30 percent up to $1,500 of the cost of efficient windows and doors, you'll need to meet the eligibility guidelines. Windows, for example, must have a U-factor and SHGC of 0.30 or less.