You may want to take advantage of the federal Residential Energy Efficiency Tax Credit, which provides homeowners with a credit equal to 30 percent of the cost of energy efficiency upgrades including windows for up to $1,500. To qualify, your windows will have to reach a certain energy efficiency standard.

Choosing Efficient Windows in San Francisco

Although San Francisco’s climate is relatively mild, ENERGY STAR windows with a U factor and SHGC of 0.3 or less will still be the best choice for energy efficiency in a new home. The U factor is most generally more important for cold climates and the SHGC is more important for hot climates, so in a mixed climate, a 0.3 for both is a good rating to look for.

If you’re planning to replace all of the windows in your existing home with energy-efficient models, you may want to get an energy audit for your home before investing in new windows. The reason for this is because although energy-efficient windows can save you money, they may not be the most cost-effective energy efficiency improvement for an existing home. An audit will analyze your home as a system and may find that you’d save more energy and money by upgrading your attic insulation or sealing your ducts. These measures are also much less expensive than replacing windows, so you would likely have a much faster return on your investment.

If you’d like an idea of what measures might be most effective for your home, check out our quick and easy online auditor. This tool will calculate how well your home performs, give you a list of upgrade suggestions and estimate how much money the upgrades can help you save.

Updated July 20, 2010