Buying New Windows

Courtesy of EnergyStar


Examine the expense, the selections, the value


So your old windows are hard to open and close, your window sills and frames are old and beyond repair, you're putting new siding on your home or you can simply afford to upgrade right now.  Where do you begin?


Go Deeper ...

Design Pressure rating (DP) measures the amount of pressure a window will withstand when closed and locked.  This rating also establishes air and water penetration, structural pressure, forced entry and operational force.  The higher the DP number, the better the performance.

Low emissivity (low-E) denotes a material's ability to restrict the transmission of radiant heat.  Such materials are designed to help keep heat inside in winter and outside in summer.

R-value measures a material's resistance to heat loss.  The higher the R-value of your window, the more efficient it will be.

The SHGC - Solar Heat Gain Coefficient - measures how well a window blocks the sun's heat.  The lower the number, the better.   In intensely sunny climates, windows can help keep the sun's heat out of a house.

The U-factor measures the rate of heat loss and how well a product insulates.  The lower the number, the better that product is at containing heat.  It's key in choosing cold-weather windows.

Visible Transmittance (VT) refers to the amount of visible light transmitted through the glass AND frame of a window.  The higher the VT, the more daylight shines through.