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Selecting the Best Windows for Your Home

Local architect Mike Di Blasi found replacement windows that match the character of his Mediterranean-style home.


Label Reading Know How
Your first and best step when shopping for replacement windows is to look for the ENERGY STAR® label. Products with this label save energy and money and help protect the environment.

A National Fenestration Rating Council (NFRC) label (shown below) provides performance factors for new windows. The most important numbers to note are U-factor, or U-value, and SHGC:

  • U-factor measures the rate of heat transfer through the window. The lower the U-factor, the better. For California, the U-factor must be less than 0.40 to meet ENERGY STAR® criteria.
  • SHGC (Solar Heat Gain Coefficient) measures heat gain from sunlight. The lower the SHGC, the better. For California, SHGC must be below 0.40 to meet ENERGY STAR® criteria.

Window Wisdom

You feel a draft in your home and wonder how cold air is getting inside. It's more likely that warm air is finding its way out - through your windows. Up to one-third of heat loss in older homes, and even some newer homes, occurs through the windows.

Rather than throw on another sweater or crank up the heat (and next month's gas bill), consider replacing your windows with energy-efficient models.

Or have these thoughts put your window upgrade plans on a permanent standstill?

I installed double-paned windows in the 1980s, so I'm set:

Today's energy-efficient windows can insulate up to four times better than the best windows available 15 years ago thanks to

  • Double, triple, even quadruple glazing
  • Thicker air spaces, up to 1 inch, between panes, as well as low-conductivity gas, such as argon, between the panes
  • Edge spacers made of silicone foam, rubber, or vinyl and frame and sash construction in vinyl and fiberglass that make windows more airtight

Energy bill savings won't cover the replacement cost for years:

According to ENERGY STAR®, the price of window replacement may not be recovered in the short term. But, your energy bills will be up to 15 percent lower, saving money in the long run. And new windows can mean a higher home resale value.

Finally, who can put a price on these benefits?

  • Fewer drafts
  • Less outside noise
  • Less fading in carpets, furniture, and artwork
  • Easier window maintenance and cleaning.

Installing replacement windows will be a nightmare in my older home:

Many Alamedans have successfully installed windows in their classic houses with energy-efficient and aesthetically pleasing results. Local architect Mike Di Blasi replaced drafty, single-pane, metal windows in his 1925 Mediterranean style home with vinyl, double-pane windows. "It was really easy," he said, "and the double-hung style of the new windows is more in keeping with the character of the house."

Your new window installation project will require review by the City of Alameda Building Department, 747-6800. Members of homeowners associations should check to see if advance approval is required as well.

Remember, even the most efficient windows can't compensate for gaps and air leak caused by poor installation. Find a qualified window installation contractor by contacting the Contractors State License Board at 800-321-CSLB or www.cslb.ca.gov.

Choosing new windows is too difficult. I'll just use extra blankets and stick with the windows I have:

These Internet sites will step you through window-buying basics, terminology, and contractor selection:

For more details on choosing your new windows, see "Label Reading Know How".

Alameda Power & Telecom, an ENERGY STAR® partner, encourages Alamedans to buy energy-efficient products.

References:
ACEEE Consumer Guide to Home Energy Savings, 8th Edition
ENERGY STAR® (www.energystar.gov)
PG&E (www.pge.com)