Not only do windows open up interior spaces to natural light and air, they are focal points to frame views to the outdoors. There are many different styles of windows, and a vast majority of the time they jive with the architectural style of a home, or at least they should. While windows are aesthetically pleasing on both the exterior and interior of your flip, they're also an important consideration for potential buyers when it comes to energy efficiency. Heat gain and heat loss through windows account for between 25 percent and 30 percent of residential heating and cooling energy use, according to the