Choosing the ideal window should not become about what looks best, instead; consider some of the needs. Most homeowners want to reduce costs, so energy efficient should most certainly become a settling detail. Nearly every manufacture offers numerous choices of energy efficiency, but knowing and understanding the values can make a big impact in performance. For instance, the u-value; the u-value of a window is a mathematical equation carried out by the NFRC to look for the heat rate loss by any kind of window. When contemplating energy efficiency, home-owners and contractors should consider looking for a low u-value within a window that fits the budget.
Security should be another concern for homeowners. Several low income communities employ glass block windows for security; while other neighborhoods take the benefit of glass block through not only their security features, but the light transmission and privacy levels. It is the light transmission and privacy offered by glass block that encourages homeowners to pay for glass block windows. They remove cost of window treatments for privacy, but still allow the natural light to illuminate their home.
The U.S. made four inch glass block has a U-value of .51 and the newer energy efficient glass block has a U-value of .35. Most single hung and double hung windows today have a U-values as high as .65 and as low as .29, It is all dependent on the needs and options considered by the homeowner.